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Home , Cyclosporiasis, Gonorrhea, Pontiac fever, Shigella boydii, Shigella sonnei, Shigellosis

State of Illinois Pat Quinn, Governor Department of Damon T. Arnold, M.D., M.P.H., Director

The Epidemiology of Infectious Diseases in Illinois, 2006 The Epidemiology of Infectious Diseases in Illinois, 2006 TABLE OF CONTENTS

Reportable Communicable Diseases in Illinois ...... 1 2006 Summary of Selected Illinois Infectious Diseases ...... 3 Acquired Immune Deficiency Syndrome/Human Immunodeficiency ...... 6 Amebiasis ...... 11 Blastomycosis ...... 13 ...... 15 ...... 17 ...... 20 Central Nervous System ...... 23 Aseptic or Encephalitis of Unknown Etiology ...... 24 Aseptic Meningitis or Encephalitis of Known Etiology, Excluding Arboviruses ...... 26 Arboviral Infections ...... 28 influenzae (Invasive Disease) ...... 37 ...... 40 meningitidis, Invasive ...... 42 ,Group B, Invasive ...... 46 ……………. ……… …….. …….. ……… …….. …….. ……… …….. ……48 ...... 49 Cyclosporiasis ...... 52 ...... 53 Producing E. coli, Enterotoxigenic E. coli, Enteropathogenic E. coli ...... 56 Foodborne and waterborne outbreaks ...... 61 Giardiasis ...... 88 Hemolytic Uremic Syndrome ...... 92 ...... 94 ...... 98 Hepatitis C, Acute...... …...... 101 Hepatitis C, Chronic or Resolved ...... 103 Histoplasmosis ...... 105 Legionellosis ...... 108 ...... 112 ...... 118 Measles ...... 123 Mumps ...... 125 Orf ...... 128 Pertussis ...... 129 Q ...... 132 Rabies ...... 134 Rabies, Potential Human Exposure ...... 144 Rocky Mountain ...... 149 (Non-Typhoidal) ...... 152 Sexually Transmitted Diseases ...... …… ...... 163 ...... 163 ...... 165 ...... 167 ...... 170 Staphylococcus aureus, Intermediate or High Level Resistance ...... 177 Streptococcus pyogenes, Group A (Invasive Disease) ...... 178 S. pneumoniae, Invasive ...... 181 Tetanus ...... 184 Tick-borne Diseases Found in Illinois ...... 185 Due to Staphylococcus aureus ...... 187 Tuberculosis ...... 189 ...... 193 ...... 195 Varicella ...... 197 Vibrio, Non-cholera...... 199 ...... 201 Non-foodborne, Non-waterborne Outbreaks, 2006 ...... 203 Reported Cases of Infectious Diseases in Illinois, 2006 ...... 233 Methods ...... 234 Reportable Communicable Diseases in Illinois The following diseases must be reported to local health authorities in Illinois (those in bold are also nationally notifiable, which means reportable by the state health department to the U.S. Centers for Disease Control and Prevention):

CLASS 1(a) - The following diseases are reportable by telephone immediately (within three hours): 1. Anthrax 5. Smallpox 2. Botulism, foodborne 6. Tularemia 3. 7. Any suspected bioterrorist threat 4. Q-fever or event

CLASS 1(b) -The following diseases are reportable within 24 hours of diagnosis: 1. Botulism, infant, wound, and other 12. Measles 2. Cholera 13. Pertussis 3. of the newborn 14. Poliomyelitis 4. Diphtheria 15. Rabies, human 5. Foodborne or waterborne illness 16. Rabies, potential human exposure 6. Hemolytic uremic syndrome, post-diarrheal 17. Typhoid fever 7. Hepatitis A 18. 8. Any unusual case or cluster of cases that may 19. Enteric infections indicate a public health hazard (E. coli)0157:H7 and other 9. , meningitis and other enterohemorrhagic E. coli, invasive disease enterotoxigenic E. coli) 10. . Meningitis and invasive enteropathogenic E. coli) disease 20. Staphylococcus aureus infections with 11. Streptococcal infections, Group A, invasive intermediate or high level (Including toxic shock syndrome) and sequelae resistance to vancomycin to group A streptococcal infections (rheumatic fever and acute glomerulonephritis)

(Continued on attached page)

1 CLASS II-The following diseases shall be reported as soon as possible during normal business hours, but within seven days (exceptions to the seven-day notification requirement are marked with an asterisk; see note below.) 1. AIDS 27. Malaria 2. Amebiasis 28. Meningitis, aseptic (including arbovirus ) 3. Blastomycosis 29. Mumps 4. Brucellosis 30. Ophthalmia neonatorum (gonococcal)* 5. Campylobacteriosis 31. Psittacosis 6. Chanchroid* 32. Reye’s syndrome 7. Chickenpox 33. Rocky Mountain spotted fever 8. Chlamydia* 34. Rubella, including congenital 9. Cryptosporidiosis 35. Salmonellosis (other than typhoid) 10. Cyclosporiasis 36. Shigellosis 11. Ehrlichiosis, human 37. Staphylococcus aureus infection, toxic shock granulocytic syndrome 12. Ehrlichiosis, human 38. Staphylococcus aureus infections occurring in monocytic infants under 28 days of age (within a health care 13. Encephalitis care institution or with onset after discharge) 14. Giardiasis 39. Streptococcal infections, group B, invasive disease, 15. Gonorrhea* of the newborn 16. Hantavirus pulmonary 40. Streptococcus pneumoniae, invasive disease syndrome (including susceptibility test results) 17. Hepatitis B 41. Syphilis* 18. Hepatitis C 42. Tetanus 19. Hepatitis, viral, other 43. 20. Histoplasmosis 44. Tuberculosis 21. HIV infection 1 45. Yersiniosis 22. Legionnaires’ disease 23. 24. 25. Listeriosis 26. Lyme disease *Must be reported by mail or by telephone to the local health authority within five days The occurrence of any increase in incidence of disease of unknown or unusual etiology should be reported, with major listed. When an epidemic of a disease dangerous to the public health occurs and present rules are not adequate for its control or prevention, more stringent requirements shall be issued by the Illinois Department of Public Health.

2 2006 Summary of Selected Illinois Infectious Diseases In Illinois, the communicable disease (CD) surveillance system relies on the passive reporting of cases required by state law. Diseases are made reportable because regular and timely information is necessary for prevention and control efforts. The current reportable disease list mandates reporting, within specific time frames, of certain diseases and of selected positive laboratory tests. Surveillance of notifiable diseases provides public health workers the opportunity to ensure that ill persons receive appropriate treatment, provide contacts with needed or other preventive treatments, and halt outbreaks. The effectiveness of the surveillance system relies heavily on the support of health care providers, laboratories and local health departments in submitting information on reportable disease cases. In Illinois, regulations require reporting by physicians, nurses, nurses aides, dentists, health care practitioners, laboratory personnel, school personnel, long-term care personnel, day care personnel, and university personnel. Notifiable disease data are submitted by the Illinois Department of Public Health (the Department) on a weekly basis to be included with national data in the Morbidity and Mortality Weekly Report (MMWR). CD rules also include laboratory reporting. Some isolates are required to be forwarded to the Department. For selected agents and situations, pulse field gel electrophoresis may be performed to subtype isolates. Three diseases – cholera, plague, and yellow fever - are internationally quarantinable and notifiable. There are 56 diseases or conditions listed as nationally reportable to the U.S. Centers for Disease Control and Prevention (CDC). This number reflects certain combinations; for example, HIV and AIDS are combined under one category as are invasive group A streptococcus (GAS) and toxic shock syndrome due to GAS. Diseases reportable to CDC but not reportable in Illinois in 2006 include individual cases of animal rabies, severe acute respiratory syndrome, varicella, coccidioidomycosis, associated pediatric mortality, and yellow fever. Animal rabies testing is only performed by state laboratories, so reporting is complete through state laboratory reporting. Other diseases in Illinois of public health importance can be reported as cases or clusters of unusual illness. Varicella and severe acute respiratory syndrome (SARS) reporting in Illinois was mandated in 2008. In 2006, the 10 most frequently reported notifiable infectious diseases (excluding AIDS) in the United States were chlamydia, giardiasis, gonorrhea, AIDS, salmonellosis, shigellosis, varicella, Lyme disease, pertussis, syphilis and tuberculosis. In 2006, 65 different types of infectious diseases were reportable to the Illinois Department of Public Health (see pages 1 and 2). Many of the reportable diseases are discussed in this annual report along with some non-reportable diseases of importance in 2006. Case numbers for the various infectious diseases listed in this summary should be considered minimum estimates. There are several reasons why reported numbers are lower than the actual incidence of disease: Many individuals do not seek medical care and thus are not diagnosed; some cases are diagnosed on a clinical basis without confirmatory or supportive laboratory testing; and among diagnosed cases, some are not reported. These surveillance data are used to evaluate disease distribution trends over time rather than to identify precisely the total number of cases occurring in the state.

3 The five most frequently reported nationally notifiable infectious diseases reported individually (not in aggregate form) in Illinois were chlamydia, gonorrhea, HIV/AIDS, and mumps. Diseases with increased reporting in 2006 over the previous five-year median included S. pneumoniae, , mumps, malaria, Lyme disease, blastomycosis, , Rocky Mountain spotted fever, cryptosporidiosis, histoplasmosis and pertussis. The number of reported cases of Giardia, N. meningitidis, shiga toxin producing E. coli, hepatitis A, varicella and Salmonella have been decreasing compared to the previous five-year median. Highlights of 2006 in Illinois included: • A case of cholera acquired overseas • A Campylobacter outbreak associated with raw milk • A multi-state Salmonella ser. Tennessee outbreak linked to peanut butter • A foodborne outbreak of vomiting in students linked to tortilla shells that had high levels of calcium propionate • Three Cryptosporidium outbreaks and one outbreak associated with recreational water were reported • More than 6,800 cases of chronic or resolved hepatitis C were reported. • There were 21 cases of Lyme disease reported with exposure in Jo Daviess County making it the Illinois county with the most reported Lyme exposures. • A mumps outbreak originating in Iowa spread to Illinois and resulted in 798 cases. • A case of orf was diagnosed in a sheep handler. • The most common bat submitted for rabies testing was the big brown bat. • One case of tetanus was reported. • An outbreak of 74 cases of Shigella were reported in attendees of a day care in Morgan County. • Person to person and foodborne outbreaks were reported and affected at least 5,729 Illinois residents.

Studies mentioned in the text of this report will be referred to in the selected readings sections. The reporting of infectious diseases by physicians, laboratory and hospital personnel, and local health departments is much appreciated. Without the support of the local health departments in following up on disease reports, it would not be possible to publish this annual report. The Department hopes you find this information useful and welcomes any suggestions on additional information that would be of use to you.

Useful Contact/Surveillance Information Illinois Department of Public Health Web site www.idph.state.il.us To report cases: Contact your local health department. To refer isolates to the Illinois Department of Public Health lab ship to one of these locations: Public Health Laboratory, 825 N. Rutledge St., Springfield, IL 62761 Public Health Laboratory, 1155 S. Oakland Ave., P.O. Box 2797, Carbondale, IL 62901

4 Public Health Laboratory, 2121 W. Taylor St., Chicago, IL 60612

5 Illinois Counties

6 Acquired Immune Deficiency Syndrome/Human Immunodeficiency Virus

Background Since the first cases were reported in the summer of 1981, acquired immune deficiency syndrome (AIDS) has become one of the major health problems to emerge in the past 25 years. In 1984, the human immunodeficiency virus (HIV) was identified as the causative agent of AIDS. The disease is spread by the exchange of blood, semen or vaginal secretions between individuals. The most common routes of are 1) having sex (anal, oral or vaginal) with an infected person, 2) sharing drug injection equipment with an infected person (including insulin or steroid needles), and 3) from mother to infant (perinatal) before or at the time of birth or through breastfeeding. Within weeks to months after infection with HIV, some individuals develop a flu- like illness. After this initial illness, individuals with HIV may remain free of clinical signs for months to years. Since the progression of HIV to AIDS is as high as 50 percent among untreated infected adults monitored for 10 years, assessing the impact of the epidemic in Illinois has relied mainly on the reporting of cases that met the AIDS definition. Clinical indicators of HIV infection may include , chronic diarrhea, weight loss, fever and followed by opportunistic infections. HIV may progress to AIDS, which includes a variety of late-term clinical manifestations including low T-cell counts. Opportunistic infections associated with AIDS include Pneumocystis carinii , chronic cryptosporidiosis, central nervous system , candidiasis, disseminated cryptococcosis, tuberculosis, disseminated atypical mycobacteriosis and some forms of infection. Some cancers also may be associated with AIDS (e.g., Kaposi sarcoma, primary B-cell lymphoma of the brain, invasive and non-Hodgkin’s lymphoma). Increased knowledge of the disease and improved diagnostic and treatment methods have led to significant advances in the clinical management of HIV and resulted in a delay in the progression from HIV to AIDS and a reduction in AIDS morbidity and mortality. A number of antiretroviral agents are available for treatment of HIV/AIDS, and combination therapies have been shown to prolong and improve the quality of life for those who are infected.

Case definition In the state of Illinois, AIDS has always been reported by the patient’s name, while HIV reporting was without patient identifiers until July 1, 1999. For HIV reporting, this meant that individuals with multiple positive test results for HIV were counted as new HIV cases each time they tested positive. Case reporting by name for HIV began on January 1, 2006.

7 Over the years, there have been three case definitions for AIDS, which should be taken into account when reviewing trends over time. The changes can be referred to as pre-1987, the 1987 revision and the 1993 revision. To review the case definitions and how they have changed over time, the following editions of the Morbidity and Mortality Weekly Reports (MMWR) should be reviewed:

1) Review of the CDC surveillance case definition for acquired immunodeficiency syndrome. MMWR 1987;36 (Suppl:)1-15s. 2) 1993 revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. MMWR 1992;41(RR- 17):1-19. 3) 1994 revised system for human immunodeficiency virus infection in children younger than 13 years of age. MMWR 1994;43(RR-12): 1-19. 4) Case definitions for infectious conditions under public health surveillance. MMWR 1997;46(RR-10): 5-6.

Additional changes, including a revised case definition for HIV infection in adults and children, became effective January 1, 2000. For information about this latest revision, see “Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome; MMWR 1999; 48 (No. RR-13)”.

Descriptive epidemiology • Number of AIDS cases reported in calendar year 2006 – 1,254. The number of reported AIDS cases declined from the 1,321 cases reported in 2005. The number of reported HIV cases was 1,876, a decline over the 3,216 reported in 2005. • Risk factors – Overall, 41 percent of AIDS cases were in MSMs, followed by 16 percent in heterosexuals (Figure 1). For HIV cases, 43 percent were in MSMs and 13 percent in IDUs (Figure 2). • The majority of reported AIDS cases in 2006 were in males (964 cases or 77 percent). For all cases reported among males, men who have sex with men (MSM) accounted for the largest number of AIDS cases (500 cases or 52 percent), followed by injection drug use (IDU) with 117 cases or 12 percent (Figure 3). • Reported cases of AIDS among females accounted for 290 cases or 23 percent of the total AIDS cases reported in 2006. Among females, heterosexual contact accounted for 132 cases or 46 percent of the total, with IDU accounting for 64 cases or 22 percent (Figure 4). • The majority of reported HIV cases in 2006 were males (1,439 or 77 percent). For all cases among males, MSM accounted for the largest number of HIV cases (807, 57 percent), followed by IDU (89 cases, 6 percent) (Figure 5). • Reported cases of HIV among females accounted for 290 or 23 percent of HIV cases reported in 2006. Among females, heterosexual contact accounted for 174 of 40 percent of the total, with IDU accounting for 65 or 15 percent of the total (Figure 6). • Age – The age distribution of HIV cases in shown in Figure 7. • Race/ethnicity - African American non-Hispanics accounted for 55 percent of the AIDS cases reported in 2006. White non-Hispanics made up 26 percent of reported AIDS cases. For reported HIV cases, African American non-Hispanics comprised 52

8 percent of cases, white non-Hispanics were 33 percent and Hispanics were 12 percent. • In 2006, Cook County and the collar counties (Dupage, Kane, Lake, McHenry and Will) comprised 81 percent of the total AIDS cases. Cook County and the collar counties comprised 80 percent of the total HIV cases.

Summary The number of cases of AIDS reported in Illinois was 1,254 and the number of HIV cases was 1,876. Most reported AIDS cases were in males. The most common risk factor for transmission for AIDS in males was MSM. Heterosexual contact was the most common risk factor for females for AIDS, followed by IDU. This year was the first for named HIV reporting.

Figure 1. Reported AIDS Cases in Illinois by Mode of Transmission, 2006

25% MSM 41% Heterosexual IDU 4% MSM/IDU 14% Undetermined/other 16%

Figure 2. Reported HIV Cases in Illinois by Mode of Transmission, 2006

MSM 34% Heterosexual 43% IDU

2% MSM/IDU Undetermined/other 8% 13%

9 Figure 3. Reported AIDS Cases in Illinois Males by Mode of Transmission, 2006

23% MSM Heterosexual 6% 52% IDU 12% MSM/IDU Undetermined/other 7%

Figure 4. Reported AIDS Cases in Illinois in Females by Mode of Transmission, 2006

31% Heterosexual 47% IDU Undetermined/other 22%

Figure 5. Reported HIV Cases in Illinois Males by Mode of Transmission, 2006

MSM 30% Heterosexual IDU 57% 2% MSM/IDU 6% Undetermined/other 5%

Figure 6. Reported HIV Cases in Illinois in Females by Mode of Transmission, 2006

40% Heterosexual 45% IDU Undetermined/other 15%

10

Figure 7. Age Distribution of HIV Cases Reported in Illinois, 2006

400 300 200 100

Number of cases Numberof 0 0-12 13-19 20-24 25-29 30-34 35-39 40-44 45-49 >49 Age in years

11 Amebiasis

Background Entamoeba histolytica is a protozoan parasite that exists in two forms: the cyst and the trophozoite. It is an important health risk to travelers to the Indian subcontinent, southern and western , the Far East, and areas of South and Central America. Intestinal disease can range from mild diarrhea to with fever, chills, weight loss and bloody or mucoid diarrhea. Extraintestinal amebiasis also can occur. Persons can develop amebic liver , which is more common in males than females. This may occur within two to four weeks of infection and include fever, cough and dull aching . Some persons are . Humans are the reservoir for Entamoeba histolytica. Infection occurs when a person ingests fecally contaminated or water that contains the cyst or through oral-anal contact. The ranges from two to four weeks. In the United States, amebiasis is most commonly seen in immigrants and travelers to foreign countries. While examination of stool for ova and parasites often is done, these tests cannot differentiate E. histolytica from nonpathogenic species like E. dispar and E. moshkovskii. There are now polymerase chain reaction (PCR) and antigen detection tests which can be used for differentiation.

Case definition The CDC case definition used by the Department for a confirmed intestinal amebiasis case is as follows: a clinically compatible illness that is laboratory confirmed by demonstration of cysts or trophozoites of E. histolytica in stool, or demonstration of trophozoites in tissue biopsy or in scraping by culture or histopathology. The definition for a case of extraintestinal amebiasis is a parasitologically confirmed infection of extraintestinal tissue; or, among symptomatic persons with clinical and/or radiographic findings consistent with extraintestinal infection, demonstration of specific antibody against E. histolytica as measured by indirect hemagglutination or enzyme-linked immunosorbent assay (ELISA).

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 75 (five-year median = 75). All cases were confirmed. From 2001 to 2006, the number of cases reported per year ranged from 43 to 130 (Figure 8). • Age - Cases ranged from 12 years to 82 years of age (mean= 34 years) (Figure 9). • Gender - Males accounted for 57 percent of cases. • Race/ethnicity - Forty percent of cases were white, 28 percent were African American, with 32 percent reporting some other racial identity; 29 percent of 59 cases for whom a response is known identified themselves as Hispanic, a significantly higher proportion than in the total Illinois population (12 percent). • Seasonal variation – There was an increase in cases in February (Figure 10). • Geographic location – Fifty-five of 74 (74 percent) of cases lived in Cook County. • Clinical outcome – Five of 24 cases with information available were admitted to the hospital, and none were known to be fatal.

12 Summary The number of cases in 2006 was higher than the five-year median, Amebiasis was significantly more common in those reporting Hispanic ethnicity.

Figure 8 . Amebiasis Cases in Illinois, 2001-2006

100 86 89 75 75 80 65 60 49 40 20

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 9. Age Distribution of Amebiasis Cases in Illinois, 2006

20 15 10 5

Number of cases Numberof 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age in years

Figure 10. Amebiasis Cases in Illinois by Month, 2006

10 8 6 4 2

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

13 Blastomycosis

Background Blastomyces dermatitidis is a dimorphic fungus found in both Canada and the United States. Blastomycosis is a zoonotic disease endemic in the midwestern United States. Occasionally, outbreaks occur in areas outside the endemic areas. The ideal area for the mycelial form of the organism is soil of warm, moist, wooded areas rich in organic debris. Recreational activities along waterways are considered to be a major risk factor for infection. Transmission is usually through inhalation of spore-laden dust. Blastomycosis most commonly presents as a subacute pulmonary disease but can range from asymptomatic to disseminated disease. For symptomatic infections, the incubation period ranges from 30 to 45 days.

Case definition The case definition for confirmed blastomycosis in Illinois is culture confirmation of Blastomyces dermatitidis. If the diagnosis was based on a needle aspirate or other diagnostic specimen with demonstration of organism resembling Blastomyces or a presumptive Blastomycosis culture, it is considered a probable case.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 119 (previous five-year median= 89). All but five cases were confirmed. From 2001 to 2006, cases per year ranged from 47 to 119 (Figure 11). The 2006 incidence rate was 0.95 per 100,000 population in Illinois. • Age - The mean age was 47 years (range 15 to 85) (Figure 12). • Gender - Seventy percent were male and males were overrepresented in cases as compared to the Illinois population. • Race/ethnicity – Forty-eight percent of the cases were white, 44 percent were African American, and 4 percent were other races; 24 percent were Hispanic. • Geographic distribution – Sixty percent of the cases had residential addresses in Cook or Lake counties. • Seasonal – There did not appear to be a seasonal pattern to the cases. • Diagnosis – Of the 119 cases reported, 113 were culture positive. Six were not culture confirmed. The most common specimen source for culture was bronchial fluid (52), skin (16), lung tissue (15) and sputum (12). • Reporting – Sixty-eight percent of reports were from infection control professionals and 30 percent from laboratory staff. • Treatment – Seventy-eight percent of cases were hospitalized; six cases were fatal with a mean age of 57 years.

Summary A higher number of blastomycosis cases were reported in 2006 (119 cases) as compared to the five-year median of 89. This is the highest number of cases reported since at least 1996. Blastomycosis cases occur predominantly in adults. Many cases had symptoms of respiratory involvement, including cough, dyspnea or hemoptysis. Ninety- five percent of reported cases were confirmed by culture. Among reported cases, 60 percent of cases reported living in Cook or Lake counties.

14

Figure 11. Blastomycosis Cases in Illinois, 2001-2006

150 119 104 89 91 100 87 47 50

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 12 . Blastomycosis Cases by Age in Illinois, 2006

40 30 20 10

Number of cases Numberof 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39yr 40-49 yr 50-59 yr >60 yr Age in years

15 Botulism

Background There are three forms of botulism: foodborne, wound, and intestinal (adult and infant). Botulism toxins cause neuromuscular blockage, which results in flaccid paralysis. All forms of botulism produce the same distinct clinical syndrome, which includes symmetrical cranial nerve palsies followed by descending flaccid symmetrical paralysis that can progress to constipation, , and death. Other symptoms of botulism include diplopia, blurred vision, abnormal body temperature, and ptosis. As botulism progresses, the patient retains intellectual function. The absence of cranial nerve palsies (blurry vision, diplopia, ptosis, facial paralysis, dysphagia, severe dry mouth) rules out a diagnosis of botulism. Differential diagnoses include myasthenia gravis and Guillain-Barré syndrome. These can be differentiated using electromyography (EMG), the pattern of paralysis and reaction to Tensilon. Foodborne botulism is caused by a neurotoxin produced by botulinum and results from ingestion of preformed toxin present in contaminated food. C. botulinum is found in soil and aquatic sediments. Seven toxins (A-G) can be produced by C. botulinum. C. baratii and C. butyricum also can produce some botulinum toxins. Human cases are caused mainly by toxin types A, B, E and, rarely, F. C. botulinum can form a spore that survives cooking and food processing measures. Spore germination can occur during anaerobic conditions, consisting of nonacidic pH and low salt and sugar content. Botulism toxins are inactivated by heating. Foodborne botulism can occur in home canned and traditional native Alaskan dishes. A large outbreak of foodborne botulism occurred in Thailand due to consumption of bamboo shoots. Forty-two of 209 patients required mechanical ventilation. Treatment for foodborne botulism is prompt administration of polyvalent equine source antitoxin which can decrease progression of paralysis but not reverse existing paralysis. Equine botulinum antitoxin for types A, B and E can prevent progression of neurologic disease if administered early in the course of illness. The most common form of intestinal botulism and of botulism in general is infant botulism. It occurs in infants younger than one year of age. Infant botulism results when swallowed spores germinate and temporarily colonize the . It is believed to occur because competing organisms are not yet present in the digestive tract. Honey consumption has been linked to some infant botulism cases but probably only accounts for about 20 percent of infections. Botulism in infants younger than 12 months of age should be suspected when constipation, lethargy, poor feeding, weak cry, bulbar palsies, and failure to thrive are present. Diagnosis of infant botulism involves detection of botulinum toxin in stool or serum by using a mouse neutralization assay or the isolation of toxigenic C. botulinum in the by enrichment culture techniques. Adult intestinal botulism is rare and occurs mainly in patients with an anatomical or functional bowel abnormality or those patients using antimicrobials, which decreases the normal flora to compete with Clostridium species. Wound botulism occurs after the causative organism contaminates a wound that is anaerobic. Wound botulism has increased in recent years due to an increase in injection drug users, especially those who use heroin. Iatrogenic botulism is caused by injection of botulinum toxin for cosmetic or therapeutic purposes. The doses used for cosmetic treatment are too low to cause systemic disease.

16 If botulism is suspected, contact your local health department immediately. This will allow for rapid investigation to identify the source. If the source was a commercial product, it can be removed promptly from the market. Twenty cases of foodborne botulism were reported in 2006 to CDC. There were also 97 cases of infant botulism and 48 cases of other types of botulism.

Case definition Botulism, infant Clinical illness may include poor feeding, constipation, failure to thrive, and respiratory failure. The case definition for infant botulism is a clinically compatible case that is laboratory confirmed, occurring in a child younger than 1 year of age. Laboratory confirmation is isolation of C. botulinum from stool or detection of botulinum toxin in stool or serum.

Botulism, foodborne Clinical illness includes diplopia, blurred vision and bulbar weakness. Symmetric paralysis may progress quickly. Laboratory confirmation consists of detection of botulinum toxin in stool, serum or patient ‘s food or isolation of C. botulinum from stool. A probable case is a clinically compatible case with an epidemiologic link (ingestion of home-canned food within the previous 48 hours). A confirmed case is a clinically compatible case that is laboratory confirmed or that occurs among persons who ate the same food as persons who have laboratory-confirmed botulism.

Botulism, wound Common symptoms include diplopia, blurred vision and bulbar weakness as well as symmetric paralysis. Laboratory confirmation is by detection of botulinum toxin in serum or isolation of C. botulinum from wound. A confirmed case is a clinically compatible illness that is laboratory confirmed in a patient who has no suspected exposure to contaminated food and who has a history of a fresh, contaminated wound during the two weeks before symptom onset.

Descriptive epidemiology • There was one case of foodborne and one infant botulism case reported in 2006. • Foodborne botulism case. This case was a 70-year-old female from Cook County with botulism toxin type B. The serum test was positive, and the stool test was negative. The person became ill while in Poland and had consumed food items in Poland. Symptoms included blurred and double vision, constipation, vomiting, and weakness. • Infant botulism case – Infant developed droopy head, ptosis, difficulty breathing, poor feeding and constipation. Mechanical ventilation was required. CDC performed testing but results are unavailable. Infant was treated with BabyBIG ®. Infant was breast fed and drank some bottled water.

Suggested readings Kongsaengdao, S. et al. An outbreak of botulism in Thailand: Clinical manifestations and management of severe respiratory failure. Clin Inf Dis 2006; 43:1247- 56.

17 Brucellosis

Background Brucellosis is a systemic bacterial infection caused by Brucella species that can cause intermittent or continuous fever and headache, lower back pain, sweating and . Chronic disease can result in in the liver, spleen, brain, bone or heart valves. The incubation period varies from two to 10 weeks (range of a few days to six months). Symptoms can last from days to years. Brucella species considered of importance in human disease include B. abortus (cattle are the primary reservoir), B. melitensis (sheep and goats are the primary reservoir) and B. suis (swine are the primary reservoir). B. melitensis has not been identified in animals in the United States since 1999. Dogs are reservoirs of B. canis but are not considered to be an important public health concern in the United States. Transmission is by contact with animal tissues, such as blood, urine, vaginal discharges, aborted fetuses and placentas and by ingestion of raw milk or other dairy products. Investigation of Brucella cases could reveal foci of infection in United States livestock that should be investigated and eliminated. The disease is most common in residents or travelers to the Mediterranean, Middle East, Mexico, and Central and South America. The large majority of human Brucella cases are thought to be due to travel outside the country and consumption of contaminated products from those countries. Brucella is also a Class A bioterrorism agent. Biosafety level 3 is recommended for laboratory manipulation of isolates. Brucella is the most commonly recognized cause of laboratory transmitted infection; about 2 percent of all Brucella cases may be laboratory acquired. The infecting dose for humans is low; the organism can enter the body in many ways including through the , conjunctivae, through the or through abraded skin. Laboratory infections have been acquired from sniffing culture plates and exposure to spills. Most cases of laboratory-acquired infection are from the more virulent B. melitensis species. Unidentified specimens are often handled on an open bench, which may result in exposures. When Brucella is suspected, the clinician or forwarding laboratory should note on the laboratory submission form, “Suspect or rule out brucellosis” so appropriate precautions can be taken. Cross reactions and false positive results can result when enzyme immunoassay tests developed for Brucella endemic areas and not approved by FDA and CLIA are used for diagnosis in the United States. Screening tests should be used in situations where there was the risk of Brucella exposure and the illness is clinically compatible. Positive screening tests should be confirmed by culture or agglutination testing before initiating prolonged antibiotic therapy or public health investigations of suspected sources. Agglutination tests detect IgM, IgG and IgA antibodies. Cross reactivity to other gram negative organisms including E. coli O157:H7, F. tularensis, Salmonella and Yersinia can occur when using enzyme immunoassay tests. In some developing countries the incidence of brucellosis may be as high as 200 per 100,000, but the disease is rare in the United States. In the United States in 2006, 121 human brucellosis cases were reported to CDC. Most were in international travelers or immigrants. Illinois was third in the nation in the number of Brucella cases reported.

18 Case definition Illinois uses the CDC case definition for brucellosis. The case definition for a confirmed case of brucellosis is a clinically compatible illness with one of the following laboratory findings: isolation of Brucella from a clinical specimen, a four-fold or greater rise in Brucella agglutination titer between acute and convalescent phase serum specimens obtained greater than or equal to two weeks apart and studied at the same laboratory, or demonstration of Brucella species in a clinical specimen by immunofluorescence. A probable case is defined as a clinically compatible case that is epidemiologically linked to a confirmed case or that has supportive serology (i.e., Brucella agglutination titer of at least 160 in one or more serum specimens obtained after symptom onset).

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – Eight (seven were confirmed, and one was probable) (See Figure 13). The five-year median was seven cases. • Age – The mean age was 28 years (range 2 to 19 years). • Gender - Three cases were male, and five were female. • Race/ethnicity – Race was known for six cases and five were white and one was other race; seven cases were Hispanic. • Geographic distribution by residence – There were five cases in Cook County, and one case each in Boone, Kane and Will counties. • Case investigations - o Cases one and two – Two children from the same family contracted B. melitensis. The two children had been in Mexico. o Case three – The case had B. melitensis biovar 1 and ate unpasturized goat cheese in Mexico. o Case four – The case had B. melitensis biovar 3 and reported no travel and no consumption of unpasteurized dairy products. o Case five – The case had B. melitensis biovar 3 and consumed unpasteurized dairy products in Spain. o Case six – The case consumed unpasteurized goat cheese from Mexico brought into this country by the father. The species was unknown. o Case seven – This case with B. melitensis reported no recent travel but had eaten unpasteurized dairy products in Mexico many years previously. The patient had backache and arthralgia. The isolate from this individual resulted in Brucella infection in two out-of-state laboratory workers. o Case eight –This case had a high titer to B. abortus, and risk factors were unknown. • Diagnosis – Cultures were Brucella positive for seven cases. Results for speciation were identified for seven isolates: B. melitensis, unknown biovar (two), B. melitensis biovar 1 (one) and B. melitensis biovar 3 (four). One probable case had a high titer to B. abortus. • Clinical syndrome – Three cases were hospitalized. No deaths were reported. • Epidemiology – Four persons of seven with an epidemiologic history reported travel overseas. Six of these individuals remembered consuming unpasteurized dairy products from other countries. Symptoms reported by cases included fever (seven cases), weight loss (seven cases), night sweats (five cases) and bone involvement

19 (three cases).

Summary In Illinois, brucellosis is an uncommon disease and tends to occur primarily in individuals who have recently traveled to foreign countries and consumed unpasteurized dairy products or who have consumed unpasteurized dairy products imported from foreign countries. In 2006, there were eight brucellosis cases reported in Illinois residents, which was the third highest number among the states reporting cases (California and Texas reported higher numbers of cases).

Suggested readings Anon. Laboratory-acquired brucellosis – Indiana and Minnesota, 2006. MMWR 2008; 57(2): 39-42. Prayle, A., et.al. Public health consequences of a false-positive laboratory test result for Brucella – Florida, Georgia and Michigan, 2005. MMWR 2008;57(22):603-6.

Figure 13. Brucellosis Cases in Illinois, 2001-2006

15 13 9 10 7 8 4 5 0

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

20 Campylobacteriosis

Background Campylobacteriosis is a zoonotic bacterial enteric disease caused primarily by and occasionally by Campylobacter coli. Campylobacter organisms are motile, gram-negative bacilli with a curved shape. The infectious dose is large. The incubation period is two to five days. Symptoms may last up to 10 days and include diarrhea, abdominal pain and fever; however, many infections are asymptomatic. Sequelae may include , febrile convulsions, a typhoid-like syndrome, Guillain-Barré syndrome or meningitis. C. jejuni infection is the most frequently identified infection preceding Guillain-Barre syndrome. Reactive arthritis can occur seven to 10 days after diarrheal illness. Excretion of the organism can occur for two to seven weeks. Approximately 1 percent of the population acquires Campylobacter each year in the United States. Among all 10 diseases under active surveillance in the federal FoodNet sites (Campylobacter, Cryptosporidium, , E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and ), infection with Campylobacter comprised 5,712 of 17,252 (33 percent) of all of those reported in 2006. The preliminary overall incidence for this infection from the 10 FoodNet sites was 12.7 per 100,000 in 2006. The 2010 national health objective is for less than 12 cases per 100,000. Campylobacter decreased 30 percent from baseline data from the FoodNet sites. In a study of nationally reported cases in six states in 2002, the median interval from symptoms to interview of patient was 18 days. The reservoir for Campylobacter is animals, most commonly poultry and cattle. The most important mode of transmission to humans is the consumption and handling of raw poultry products. Campylobacter is found in approximately 80 percent of retail chicken meat. Campylobacter is also a cause of traveler’s diarrhea. Prevention of campylobacteriosis includes cooking meat thoroughly, avoiding cross-contamination between foods and handwashing after animal handling.

Case definition The case definition for a confirmed case of campylobacteriosis in Illinois is a clinically compatible illness with isolation of Campylobacter from any clinical specimen. A probable case is a clinically compatible illness that is epidemiologically linked to a confirmed case.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 1,294 (previous five-year median = 1,265); incidence rate of 10 per 100,000 (Figure 14). All but three were confirmed cases. • Gender – Fifty-six percent of cases were male. • Age - Mean age of reported cases was 47; highest incidence rate occurred in those younger than 5 years of age and those 50 to 59 years old (Figure 15). • Race/ethnicity - The majority of cases (88 percent) were in whites, with 4 percent in , 2 percent in Asians and 5 percent in other races. Those indicating Hispanic ethnicity accounted for 12 percent of the cases. There was a significantly higher proportion of whites with campylobacteriosis and a lower proportion of African Americans with the disease than in the total Illinois population.

21 • Seasonal variation - Campylobacteriosis was reported more often in the warmer months of the year in Illinois (May through October) (Figure 16). • Geographic distribution – The five counties reporting the most cases were Cook (452), Lake (127), DuPage (107), Will (62) and Kane (54). • Clinical – Ninety-eight percent of 657 reported cases reported diarrhea. Thirty-five percent of 556 cases reported vomiting. Twenty-seven percent of 956 reported cases with hospitalization information were hospitalized. One case was reported to have died as a result of this illness. • Campylobacter species identified – The species of Campylobacter was available for 427 cases. The species was identified as jejuni (394 cases), coli (18), lari (13), rectus (one) and fetus (one). • Risk factors o Travel – Fifty-six of 417 (13 percent) reported travel to another country. Forty- three of 431 (10 percent) reported travel to another state. o Animal contact – Information on animal contact was available for 409 cases. Of these, 257 (63 percent) reported animal contact. Contact with dogs was reported for 183 individuals and contact with ill dogs was reported for 23 dog owners. Eleven specifically reported contact with ill puppies. Three individuals reported contact with multiple dogs in kennels or humane societies. Of the 409 cases with animal contact information, 104 reported contact with cats. Seven cases reported contact with cats with diarrhea with four of these seven cases reporting contact with kittens with diarrhea. • Reporting – Fifty percent of cases were reported by infection control professionals and 37 percent of cases by laboratory staff. • Outbreaks – One outbreak was reported, see foodborne outbreak section for details.

Summary The incidence of the disease in 2006 was 10 per 100,000. This rate was below the 2010 national objectives of 12 per 100,000. Campylobacter infections occur more commonly from May through October. The incidence was highest in 1- to 4-year-olds and 50- to -59-year-olds. Whites are more likely to be reported with campylobacteriosis than other races.

Suggested readings Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from http://www.cdc.gov/EID/content/14/2/311

22 Figure 14. Campylobacteriosis Cases in Illinois, 2001-2006

1500 1405 1376 1400 1265 1294 1300 1204 1235 1200

Number of cases 1100 2001 2002 2003 2004 2005 2006 Year

Figure 15 . Incidence of Campylobacteriosis Cases in Illinois by Age, 2006

20 15 10

100,000 5

Incidence per 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Year

Figure 16. Campylobacteriosis Cases in Illinois by Month, 2006

250 200 150 100 50

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

23 Central Nervous System Infections

General Both aseptic meningitis and acute encephalitis were reportable in Illinois in 2006. The purpose of this reporting is to identify arboviral infections. Control measures for arboviruses are possible and include public education and mosquito control activities. Aseptic meningitis is usually a self-limiting illness characterized by sudden onset of fever, headache and stiff . A may be present along with vomiting, photophobia and nausea. In the United States, enteroviruses cause most cases with known etiology. Some arboviral infections may present as aseptic meningitis. Acute infectious and post-infectious encephalitis were reportable in Illinois in 2006. Infections are characterized by headache, high fever, meningeal signs, stupor, disorientation, coma, tremors, convulsions or paralysis. Aseptic meningitis and encephalitis are combined into two sections: unknown etiology and known etiology. Arbovirus infections were put in a third section. Cases of each type of CNS infection are shown in Table 1 and the number of reported CNS infections by year is shown in Figure 17.

Table 1. Number of Reported CNS Infections Reported in Illinois, 2006 Type of CNS Infection 2006 Aseptic meningitis, unknown 834 etiology Aseptic meningitis, known 111 virus, not arboviral Encephalitis, acute, known 26 virus, not arboviral Encephalitis, acute, unknown 101 etiology WNV 215 California encephalitis 0 SLE 0 Dengue 6 TOTAL 1,293

Figure 17. Reported Non-bacterial CNS Infections by Year in Illinois, 2001-2006

3000 2147 1858 1528 1632 2000 1480 1293

cases 1000

# reported 0 2001 2002 2003 2004 2005 2006 Year

24 Aseptic Meningitis or Encephalitis of Unknown Etiology

Background Both aseptic meningitis and encephalitis are reportable in Illinois. One of the purposes of this reporting is to identify arboviruses. Although virus isolation and serologic testing for arboviruses (during the appropriate season) is offered for free to health care providers for all persons in the state with aseptic meningitis or encephalitis, the etiology of many cases of aseptic meningitis and encephalitis remains unknown.

Case definition The case definition for aseptic meningitis in Illinois is a clinically compatible illness diagnosed by a physician as aseptic meningitis with elevated white blood cells in the CSF but no laboratory evidence of bacterial or fungal meningitis. For aseptic meningitis of unknown etiology, no virus could be isolated from the person and testing for arboviruses was negative or testing was not done. The case definition for primary encephalitis is a clinically compatible illness diagnosed by a physician as primary encephalitis. For encephalitis of unknown etiology, no virus could be isolated from the patient and there were no positive tests for arboviruses.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 935 (834 meningitis cases and 101 encephalitis cases). • Age – The annual incidence rate was highest in those younger than 1 year of age (93 per 100,000) (Figure 18). In all other age groups, the incidence rate was below 9 per 100,000. The mean age of reported cases was 23. • Gender – Fifty-one percent were male. • Race/ethnicity – The cases were white (73 percent), African American (18 percent) and other races (8 percent); 24 percent reported Hispanic ethnicity. • Seasonal variation – Cases were most common from July through October (Figure 19); Of the total cases, 578 had onsets between May 15 and October 31 (357 cases had onsets outside of this time frame). • Geographic distribution – The highest number of cases were reported from Cook (407), DuPage (108), Lake (69), Will (62) and Kane (48).

Summary Cases of aseptic meningitis and acute encephalitis with no known cause occur with greater frequency in the summer months and in those younger than 1 year of age. However, reporting of these infections is required from May 15 through October 31 resulting in an increase in reporting during these months of the year.

25 Figure 18. Incidence of Aseptic Meningitis and Encephalitis, Unknown Etiology in Illinois by Age, 2006

100

50 100,000

Incidence per 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-59 yr > 59 yr Age groups

Figure 19. Aseptic Meningitis and Encephalitis, Unknown Etiology by Month, 2006

150 100 50 0 Number of cases Numberof Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Year

26 Aseptic Meningitis or Encephalitis of Known Etiology, Excluding Arboviruses

Background Both aseptic meningitis and encephalitis were reportable in Illinois in 2006. One of the purposes of this reporting was to identify arboviruses. Virus isolation is offered to all health care providers of persons in the state with aseptic meningitis or encephalitis, and this helps to identify the etiology of some cases. Encephalitis can be caused by infectious, postinfectious and postimmunization causes. Pathogens causing infectious encephalitis include virus, arboviruses, lymphocytic choriomeningitis, mumps, cytomegalovirus, Epstein-Barr virus, human herpesvirus 6 and enteroviruses. Herpes simplex is a common cause of acute encephalitis that occurs most frequently in children and the elderly. Many encephalitis cases in the United States and Illinois are not identified as to the etiology. Aseptic meningitis is an of the meninges that cover the brain and spinal cord. It is often caused by a virus, frequently an enterovirus. Enterovirus activity usually peaks during summer and early fall. Enterovirus illness is usually mild and only a small proportion result in aseptic meningitis. Children are at greater risk of severe manifestations with enteroviruses. Adults with enterovirus are more likely to experience upper respiratory symptoms. Enterovirus is shed in saliva and feces of infected persons. Persons should wash their hands thoroughly after using the bathroom and avoid sharing drinks and utensils during an outbreak. Enterovirus infections are not nationally notifiable. Seroypes of human enteroviruses are classified into echoviruses, coxsackieviruses and polioviruses. From 1970 through 2005, the five enteroviruses most commonly reported to CDC through the national voluntary enterovirus typing included echoviruses 9,11,30 and 6 and coxsackie B5. Children younger than 1 year of age accounted for 44 percent of reports. Seventy- eight percent of reports were reported from June through October. Cerebrospinal fluid was the most common specimen type followed by respiratory and fecal submissions. They are reportable in Illinois as a part of the state aseptic meningitis reporting.

Case definition The case definition for aseptic meningitis in Illinois is a clinically compatible illness diagnosed by a physician as aseptic meningitis with elevated white blood cells (greater than 4 cells) in the CSF but no laboratory evidence of bacterial or fungal meningitis. For aseptic meningitis of known etiology, a virus could be isolated from the person and no arbovirus testing was positive in specimens from the person. The case definition for primary encephalitis is a clinically compatible illness diagnosed by a physician as primary encephalitis. For encephalitis of known etiology, a virus could be isolated from the patient and there was no positive test for arboviruses.

Descriptive epidemiology • Number of cases – The number of cases reported was 137 cases (111 meningitis and 26 encephalitis). • Age – The mean age was 29 years. • Gender – Fifty-three percent of cases were male. • Race/ethnicity – Seventy-four percent were white, 19 percent African American and 7 percent other races; 15 percent were Hispanic.

27 • Seasonal variation - Aseptic meningitis or encephalitis of known etiology, excluding arboviruses were most commonly reported from August through September (Figure 20). Of the 137 cases, 89 cases (65 percent) had onsets during arbovirus season from May 15 through October 31. • Geographic – The three counties reporting the highest number of cases were Cook (52), Winnebago (11) and Sangamon (10). • Diagnosis – identified as the etiologic agent were enterovirus, not further specified (64), herpes simplex (31), echovirus 6 (four), coxsackie B5 (three), echovirus, not further specified (three), echovirus 9 (two), coxsackie B3 (one) and coxsackie B4 (one). Unknown viruses were specified in 15 cases. Other types of organisms reported as etiologic agents included Cryptococcus (13). Summary In 358 of 1,293 (28 percent) of encephalitis and aseptic meningitis cases, an etiologic agent (including arboviruses) was identified as the cause of illness. Herpes simplex, coxsackie B5 and echovirus 6 were the most common specific viruses identified as the causative agents for aseptic meningitis and encephalitis cases. Arbovirus cases are described in a later section.

Figure 20. Aseptic Meningitis and Encephalitis, Non-Arbovirus, Known Etiology by Month, 2006

30 20 10 0 Number of cases Numberof Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Year

28 Arboviral Infections

Background Arboviruses that cause encephalitis are members of the Togaviridae, Flaviviridae or Bunyaviridae families. Humans and domestic animals, such as horses, can develop clinical disease but are usually dead-end hosts because they do not develop sufficient viremia to contribute to the transmission cycle. Arboviral infections that have ever been reported in Illinois residents due to exposure in Illinois include those due to St. Louis encephalitis (SLE), West Nile virus (WNV), California encephalitis (CE) and Western equine encephalitis (WEE) viruses. WEE has not been seen in Illinois since the 1960s. The most likely mosquito-borne diseases to occur in people in Illinois as of 2004 are WNV and CE.

WNV background WNV is a flavivirus in the Japanese encephalitis antigenic complex. Birds become infected from mosquitoes. Bird-to-bird transmission also may occur. WNV is maintained in a bird-mosquito-bird cycle with passerine birds as the primary amplifiers. Mosquitoes from the Culex genus are the primary WNV vectors. The incubation period for WNV is three to 14 days in people. WNV can cause a wide variety of clinical syndromes, including fever, meningitis, encephalitis and a flaccid paralysis characteristic of a poliomyelitis-like syndrome. About 80 percent of human infections are asymptomatic. Febrile illness (fever, headache, fatigue, backache, myalgia) is not uncommon. Gastrointestinal symptoms and a rash also may occur. The rash is usually maculopapular and appears between days five to 12 of illness. WNV produces a viremia that tends to disappear with the onset of clinical symptoms. Persons with West Nile meningitis often are hospitalized for pain control or rehydration. Most patients return home to independent living. West Nile encephalitis occurs more often in persons with immunosuppression or persons greater than 55 years of age. Physical, occupational or speech therapy is frequently needed in patients following West Nile encephalitis. Approximately 75 percent may require some type of assisted care after West Nile encephalitis. IgM antibodies can persist for up to a year following infection. Screening of blood donations for WNV began in June 2003. In a study of blood donors, the median time from WNV RNA detection to IgM seroconversion was four days and eight days to IgG conversion. The mean time to IgM negativity was 156 days. A study in Ohio in 2002 showed that only 44 percent of their study population avoided mosquitoes and only 17 percent used repellents regularly. Children spent more time outside than adults. Most of the information about WNV was obtained from television. In the United States, total human cases reported to CDC by year are as follows, 2000 (21), 2001 (66), 2002 (4,156), 2003 (9,862), 2004 (1,604) and 2005 (3,000) and 2006 (4,269). In 2006, 1,459 neuroinvasive, 2,616 WNV fever and 194 other clinical cases were reported in the United States from 43 states with 177 deaths reported. WNV activity occurred in 48 states. In Washington state, cases were reported for the first time. More than 30 percent of WNV neuroinvasive cases were from three states (Idaho, Illinois and Texas). In addition, 43 states reported WNV-infected dead birds, and 34 states reported WNV-infected horses. Culex mosquitoes accounted for 73 percent of WNV positive pools. From 2002 to 2006, cumulative incidence per state of WNV neuroinvasive

29 disease ranged from 0.2 to 32.2 per 100,000 population. The highest rates were in the northern Great Plains.

California encephalitis background CE virus is the main cause of pediatric encephalitis in the United States. The illness occurs most commonly in children younger than 15 years of age. In Illinois, cases of CE virus infection are most often reported from Peoria, Tazewell and Woodford counties. The main vector is thought to be Ochlerotatus triseriatus (tree hole mosquitoes), a container-breeding mosquito. Therefore, human activities which can increase the numbers of containers, such as tires or buckets, can increase the population of the tree hole mosquito. In 2006, the IDPH lab tested only those persons negative for WNV and younger than 18 years of age for CE due to limitations on reagents for testing. A total of 67 cases were reported in the United States from 12 states.

Saint Louis encephalitis and other arboviruses background SLE also can be identified in persons in Illinois. In 2006, 10 cases of SLE were reported from eight states. In the United States, there were also eight cases of EEE reported, one case of Powassan and no cases of WEE.

Non-endemic arboviruses background Several arboviruses seen in Illinois result from traveling overseas, including Dengue and Chikungunya. Chikungunya virus is transmitted by the Aedes mosquito. And is indigenous to tropical Africa and Asia. The primary reservoirs are primates and rodents. The incubation period is usually two to four days. Chikungunya virus is an illness characterized by fever, myalgias, lower back pain and accompanied by rash and . The arthritis primarily affects smaller joints such as the wrists and ankles. Most Chikungunya infections are asymptomatic. The diagnosis should be considered in travelers to endemic areas who have fever and arthritis. Serologic testing may be negative during the first week of infection. RT-PCR testing may be more sensitive early in the course of illness. Patients may be viremic for six to seven days (shortly before and during the febrile period). No autochtonous cases have occurred yet in the United States. Treatment consists of supportive care, including analgesics and anti-inflammatory . From 2005 to 2006, an epidemic occurred on islands in the Indian Ocean and in India. Thirty-seven cases were reported in United States travelers in 2006. In 2006, Chikungunya cases were also reported in residents of , Canada, the Caribbean and South Africa after travel to endemic areas. In a study of travelers in 2006 with symptoms of Chikungunya, travelers to the Indian Ocean Islands (Mauritius, Reunion and Madagascar) had the highest risk of infection. A rash was typically associated with the Chikungunya cases. Dengue is an arbovirus caused by four (DEN-1, DEN-2, DEN-3 and DEN-4). Dengue is the most common arbovirus in tropical and subtropical parts of the world. United States residents who travel to countries with endemic Dengue are at risk for the disease. The incubation period ranges from three to 14 days. Dengue infection can range from asymptomatic to mild to severe disease. A second infection with a different can result in Dengue hemorrhagic fever. Persons traveling to areas with Dengue should wear repellents and protective clothing. Diagnosis is by acute and convalescent serum samples. Dengue is not nationally notifiable. In a study of travelers

30 visiting a GeoSentinel surveillance clinic, 6 percent of persons returning with febrile illness had Dengue.

Arbovirus prevention background Arboviral encephalitis prevention includes limiting mosquito bites in humans and reducing mosquito habitat. Mosquito bites can be minimized by using appropriate repellents, by avoiding the outdoors during peak mosquito feeding times and by repairing screens on windows and doors. The use of repellents provides the best protection against mosquitoes. Prevention involves personal protective behaviors and mosquito control activities. People can eliminate breeding areas for mosquitoes such as standing water in clogged rain gutters. During the period May 15 through October 31, physicians and laboratories in Illinois are encouraged to submit cerebrospinal fluid (CSF) from aseptic meningitis and encephalitis cases to the Department laboratory for further testing. In addition, serum samples are requested for testing for arboviral antibody from clinically compatible cases. The CSF can be examined for antibodies to LAC, SLE and Eastern equine encephalitis.

Case definition The case definition for a confirmed case of arboviral encephalitis in Illinois is a clinically compatible illness that is laboratory confirmed at either commercial laboratories or public health laboratories. The laboratory criteria are a fourfold or greater rise in serum antibody titer; or isolation of virus from, or demonstration of viral antigen in tissue, blood, CSF or other body fluid; or specific IgM antibody in CSF. A probable case of arboviral encephalitis is a clinically compatible illness occurring during the season when arbovirus transmission is likely to occur and with the following supportive serology: a stable (twofold or smaller change) elevated antibody titer to an arbovirus, e.g., at least 320 by hemagglutination inhibition, at least 128 by complement fixation (CF), at least 256 by IF, at least 160 by neutralization, or a positive serologic result by enzyme immunoassay (EIA).

Descriptive epidemiology

California encephalitis surveillance No cases of California encephalitis were identified in Illinois in 2006.

• Past incidence - The reported cases of CE in Illinois are as follows: 1990 (one), 1991 (15), 1992 (seven), 1993 (two), 1994 (six), 1995 (five), 1996 (13), 1997 (three), 1998 (four), 1999 (three), 2000 (three), 2001 (five), 2002 (eight), 2003 (11), 2004 (eight) and 2005 (one) (Figure 21).

Chikungunya Surveillance • Number of cases reported in Illinois – Seven Chikungunya cases were reported in Illinois. Two cases were confirmed, and five cases were classified as probable. Virus was isolated from one patient specimen at CDC. • Age – Ages ranged from 29 to 78 years of age. The mean age was 57. • Gender – Five cases were male and two were female. • Race/ethnicity –Six of the cases were Asian and one was white. None reported

31 Hispanic ethnicity. • County of residence – Five of the cases resided in Cook County, and one each of the cases resided in DuPage County and Will County. • Clinical syndrome – Seven of the cases reported fever, six reported joint pain, and two each reported rash, weakness and vomiting. • Treatment - Two of three cases with a known hospitalization history were hospitalized. Of three cases with information available, none died. • Seasonal distribution – Case onsets were reported from June through November. • Travel – All cases had traveled to India prior to illness onset. • Case descriptions o One case was a 65-year-old female who traveled to India from May 27 to June 25. She had onset of illness on June 5. Serum was collected on July 5. She would not have been viremic upon her return to the United States on June 25. o A second case was a 53-year-old male with travel to India (return date August 17). Onset of illness was August 3 with serum collected on August 23. The patient may have been viremic while in the United States. o A third case was a 40-year-old Will County resident who traveled to India (dates not specified). Onset of illness was July 28 and serum was collected on September 12 (Day 46). o The fourth case was a 29-year-old male who had travel to India from June 24 through August 9. Onset of illness was August 4 and serum was collected on September 5 (day 35). o The fifth case was a 74-year-old male from Cook County with onset on November 3. He traveled to India from May 1 through November 1. o The sixth case was a 61-year-old male with onset of July 16. He traveled to India from June 21 through July 9. o The final case was a 78-year-old Asian male from Cook County with onset on September 29. He traveled to India from September 15 to September 29. Virus was isolated from this patient at CDC.

SLE surveillance Occurrence - No cases of SLE were reported in 2006.

Dengue surveillance • Number of cases reported in Illinois – Six cases of dengue were reported in 2006; all were designated as probable. • Geographic Distribution - Cases were reported from Cook (three), DuPage (two) and Winnebago (one) counties. • Age – The age of the cases ranged from 27 to 66 years. The mean age was 44 years. • Gender – Four of the cases were male and two were female. • Race/ethnicity – The race of three cases was known. Two were white and one was African American; one case was Hispanic. • Clinical presentation – All cases developed a fever. • Hospitalization – Three cases were hospitalized. • Fatalities – No fatalities were reported.

32 • Travel – All cases had a history of travel outside of the continental United States. Three traveled to Mexico, one to the Philippines, one to Puerto Rico and one to an unknown destination. • Seasonal distribution – Onsets of cases were reported from March through November. • Past incidence - The reported cases of dengue in Illinois residents for prior years are as follows: 1990 (none), 1991 (none), 1992 (none), 1993 (one), 1994 (two), 1995 (two), 1996 (none), 1997 (four), 1998 (one), 1999 (two), 2000 (two), 2001 (two) and 2002 (none), 2003 (none), 2004 (three) and 2005 (one).

West Nile virus surveillance More than 60 agencies participated in bird and mosquito surveillance in Illinois in 2006.

Human • Number of cases reported in Illinois – Two hundred fifteen WNV cases were reported; 84 (39 percent) were confirmed and 131 (61 percent) were classified as probable. The incidence in Illinois was 1.7 cases per 100,000 population. • Age – Ages ranged from 2 years to 91 years of age (mean = 53 years) (Figure 22). • Gender – One hundred twelve (52 percent) of the cases were male. • Race/ethnicity – Cases reported the following race, white (85 percent), African American (9 percent) and other (3 percent). Six percent of 168 cases reported being Hispanic. • Clinical presentation – Cases were classified as: WNF (69), neuroinvasive disease (127) and other (19) (Figure 23). Of the neuroinvasive cases, 76 were classified as encephalitis, 46 were classified as meningitis and five were classified as flaccid paralysis. For individuals older than 59 years of age, 69 percent had neuroinvasive disease as compared to 53 percent of those younger than 60 years of age. Cases exhibited the following symptoms: fever, 187 (89 percent); stiff neck, 69 (35 percent); rash, 65 (33 percent) and change in consciousness, 61 (33 percent). Sixteen persons were reported to have been on ventilators. • Hospitalization – One hundred fifty of 199 (75 percent) cases were hospitalized. • Fatalities – Ten cases were fatal. Due to age and underlying illness the direct cause of death may not have been WNV. All but two fatal cases had neuroinvasive disease. Fatal cases ranged in age from 56 to 90 years of age (mean = 76 years). • Diagnosis – The Department’s laboratory performed the MAC ELISA test on all submitted specimens. This was the first year that clinically compatible cases without laboratory confirmation at a public health laboratory could be counted as cases in Illinois. Of the reported cases, positive tests occurred as follows: both serum and CSF (39), CSF only (42) and serum only (134). • Seasonal distribution – Onset of cases ranged from May 27 (Kane County) through October 11 (Moultrie County). The highest number of case onsets occurred in August. Figure 24 shows the number of WNV infections by week. • Geographic distribution – Thirty-eight counties had evidence of WNV activity in humans (Figure 25). The largest number of cases per county (86, 40 percent) occurred in Cook County (incidence per 100,000 population = 1.5). Incidence

33 rates in selected other counties were DuPage (43, 5 per 100,000), Will (18, 4 per 100,000) and Lake (11, 2 per 100,000). • Reporting – Of the 200 cases with the reporting source listed, the most frequent reporters were infection control professionals (48 percent) and laboratory staff (51 percent). • Historical – The number of cases in Illinois was 2002 (884), 2003 (53), 2004 (60), and in 2005 (252).

Bird testing The number of counties submitting birds for WNV testing: 2004 (69), 2005 (62), and 2006 (89). Fifty-six counties in 2006 reported positive birds (63 percent of counties submitting birds for testing). Bird types that could be submitted for WNV testing was expanded to include robins, grackles, starlings, sparrows, blackbirds, cardinals and mourning doves as well as crows and blue jays. The total submitted for each species : crow (90, 64 percent positive), blue jay (57, 54 percent), house sparrow (14, 21 percent), house finch (10, 20 percent), grackle (39, 10 percent) and robin (83, 8 percent). In August, 40 percent of robins tested positive. Twenty-six other types of birds were submitted with 8 percent testing positive. Birds submitted but not testing positive included mourning dove (seven), cardinal (six), blackbird (eight) and starling (13). Birds were tested using immunohistochemistry testing (IHC). The first positive bird of the season was collected on May 24 from Cook County and the last positive bird of the season was collected on November 30 from Cook County.

Mosquito pool testing In 2006, 45 of 62 counties submitting mosquito pools for testing (73 percent) had pools which tested positive. For 2004 and 2005, 48 percent of counties had mosquito pools that tested positive. The mosquito pool testing was 2004 (66 counties submitted, with 32 positive) and 2005 (64 submitted, 31 positive). The first positive mosquito sample was collected on May 20, 2006. In 2006, of 4,047 mosquito pools (26 percent) tested positive.

WNV horse testing Twenty-one horses were reported with WNV in 2006. Seven horses died or were euthanized due to WNV resulting in a 33 percent fatality rate. None of the 21 horses were up-to-date on WNV . Horses were from Boone (two), Bureau (two), Effingham (two), Will (two) and one each from Christian, Henderson, Henry, Jackson, Kankakee, Lake, LaSalle, Lawrence, Lee, Marion, McHenry, Randolph and Sangamon. Date of report ranged from August 22 (Marion County) to October 29 (Jackson County). All were symptomatic and all tested positive by IgM ELISA.

Other species No other animals were positive for WNV in 2006.

Summary Because encephalitis cases are more commonly reported in the summer months in Illinois, the Department asks physicians to increase testing to establish the etiology

34 and to report individuals with acute encephalitis from May 15 to October 31 each year. This was the fifth year for humans to test positive for WNV in Illinois. Dead crows and blue jays tested positive for WNV in counties in Illinois. Positive dead birds were collected in Illinois between May 24 and November 30. There were no cases of CE and no cases of SLE reported in 2006. Illinois had the second highest number of reported WNV cases in the United States. During 2006, human WNV cases were reported from 38 of the 102 counties in Illinois. In 2006, the majority of the cases were in the Chicago metropolitan area.

Suggested readings Borgherini, G., et al. Outbreak of Chikungunya on Reunion Island: Early Clinical and Laboratory Features in 157 Adult Patients. CID 2007; 44:1401-07. Brown, H.E. et. al., Ecological factors associated with West nile virus transmission, Northeastern United States. Emerg Inf Dis 2008;14(10):1539-45. Division of Vector Borne Infectious Diseases, National center for Zoonotic, Vector- borne, and enteric diseases et al. Update: Chikungunya fever diagnosed among international Travelers – United States, 2006. MMWR March 30, 2007; 276-77. Busch, M.P., et. al., Virus and antibody dynamics in acute West Nile virus infection. JID 2008;198:984-993. Lanciotti, R.S., et al. Chikungunya virus in US travelers returning from India, 2006. Emerg Inf Dis 2007;13(5): 764-7. LeBeaud, A.D., et. al., Exposure to West Nile virus during the 2002 epidemic in Cuyahoga County, Ohio: A comparison of pediatric and adult behaviors. Pub Health Reports 2007;122 :356-361. Lindsey, N.P., et al. West nile virus neuroinvasive disease incidence in the United States, 2002-2006. Vector-borne and zoonotic diseases 2008; 8(1), 35-39. Nicoletti, L., et al. Chikungunya and Dengue viruses in travelers. Emerg Inf Dis [serial on the internet]. 2008 Jan. Available from http://www.cdc.gov/EID/content/14/1/177.htm. Sejvar, J.J. The long-term outcomes of human West Nile virus infection. CID 2007;44:1617-24. Taubitz, W., et al. Chikungunya fever in travelers: Clinical, presentation and course. CID 2007;45:1-4. Warner, E., et al. Chikungunya fever diagnosed among international travelers – United States, 2005-2006. MMWR 2006; 55(38):1040-2. Wichmann, O., et al. Severe Dengue Virus Infection in Traveler : Risk Factors and Laboratory Indicators. JID 2007; 195; 1089-96. Wilder-Smith, A. and Tambyah, P.A. Severe Dengue Virus Infection in Travelers. JID 2007; 195:1081-83. Wilson, M.E., et al. Fever in returned travelers: Results from the GeoSentinel surveillance network. CID 2007;44:1560-8.

35 Figure 21. California Encephalitis Cases in Illinois, 2001-2006

15 11 9 10 8 5 5 1 0

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 22 . Reported WNV Cases in Illinois by Age, 2006

80 60 40 20

Number of cases Numberof 0 0-14 yrs 15-29 yrs 30-44 yrs 45-59 yrs 60-74 yrs >74 yrs Age category

Figure 23. Clinical Syndrome for WNV Cases in Illinois, 2006

Other 11% WNV fever WNV fever WNV aseptic 32% meningitis WNV encephalitis 21% WNV aseptic meningitis Other WNV encephalitis 36%

Figure 24. Epidemic Curve for Human WNV Cases in Illinois, 2006

200 150 100 50

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Week of onset

36 Figure 25. Map of Human WNV Cases in Illinois by County, 2006

37 Haemophilus influenzae (Invasive Disease)

Background Haemophilus influenzae is an obligate pathogen of the human respiratory tract and can cause invasive disease such as meningitis, , pneumonia, and bacteremia. H. influenzae forms part of the normal flora of the human throat and is divided into six serotypes (a through f). The polysaccharide capsule is a known virulence factor and is the antigen used in serotyping. The organism is transmitted by droplets and discharges from the nose and throat. The incubation period is probably short, from two to four days. Children younger than 5 years of age should be vaccinated against H. influenzae. Prior to the introduction of against serotype b, most cases were due to serotype b. In 2006, 383 cases were reported in those younger than 5 years of age in the United States. Eight percent of all cases in children younger than five years of age were attributable to type B. Incidence has declined 99 percent since the pre-vaccination time period. In the post-vaccine era, nontypable serotypes have increased. In the United States, the incidence of all cases of invasive H. influenzae was 0.82 per 100,000 population. In the CDC Active Bacterial Core (ABC) Surveillance System sites in 2006, 3 percent of H. influenzae isolates were type B and 71 percent were non typable. The incidence was 1.6 per 100,000 at these sites.

Case definition The case definition for a confirmed case of invasive H. influenzae in Illinois is a clinically compatible illness with isolation of the organism from a normally sterile site. A probable case is a clinically compatible illness and detection of H. influenzae type b antigen in CSF.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 120 (five-year median = 120). The incidence was 0.96 per 100,000. All cases were confirmed. From 2001 to 2006, the number of cases reported per year ranged from 103 to 135 (Figure 26). • Age – Fifty-six percent of the cases were older than 49 years of age (mean = 55 years of age) (Figure 27). Two type b cases were in persons younger than 5years of age. • Gender - Fifty-five percent of cases were female. • Race/ethnicity - Fourteen percent were African Americans, 83 percent were white, and 3 percent were other races; 12 percent were Hispanic. • Seasonal distribution – H. influenzae occurs throughout the year, with an increase in the winter months (Figure 28). • Presentation – The case presentations were bacteremia (61 percent), pneumonia (24 percent), meningitis (9 percent), other (4 percent) and multiple (2 percent). • Treatment – Ninety-two percent of 111 reported cases for which information was available were hospitalized. • Serotype results – Typing results were available for 101 of 120 (84 percent) of isolates. For the 101 cases with typing available, the following serotypes were identified: f (20 cases), b (11 cases), e (nine cases), d (two cases) and a (four

38 cases. Eleven percent were type b. Fifty-five (54 percent) of the isolates were non-typable. • Mortality – Nine of 75 (12 percent) cases for which information was available died. Ages of the fatal cases ranged from 78 to 100. • Diagnosis - All cases were culture confirmed. H. influenzae was isolated from blood (102 cases), CSF (six cases) and CSF and blood (four). • Geographic location – Thirty-five percent of the cases resided in Cook County. • Epidemiology – One case was from a day care facility and five lived in residential facilities. • Reporting – All cases had a reporter listed. Reporters included infection control professionals (94), laboratory staff (22), and other (four).

Summary The number of H. influenzae cases in 2006 was the same as the five-year median. The incidence in Illinois (0.96 per 100,000) was lower than in CDC’s ABC sites (1.6 per 100,000). Of the isolates that were typed, 11 percent were type b as compared to 3 percent in CDC’s ABC sites. Cases occur throughout the year. Two type b cases occurred in children younger than 5 years of age for whom the vaccine is indicated. The 11 percent of isolates serotyped as type b was similar to the 13 percent seen in 2005. Fifty-four percent of cases in 2006 were untypable as compared to 71 percent in CDC’s ABC site in 2006. Fifty-six percent of all cases occurred in people older than 49 years of age.

Suggested readings CDC, 2007. Active bacterial core surveillance report, Emerging Infections Program Network, Haemophilus influenzae, 2006. Available via the Internet: http://www.cdc.gov/ncidod/dbmd/abcs/survreports/hib06.pdf Tsang, R.S.W., et al. Characterization of invasive Haemophilus influenzae disease in Manitoba, Canada, 2000-2006: Invasive disease due to non-type B strains. CID 2007;44:1611-4.

39 Figure 26. H. influenzae Cases in Illinois, 2001-2006

135 150 120 124 120 103 109 100

50

Number of cases of Number 0 2001 2002 2003 2004 2005 2006 Year

Figure 27. H. influenzae Cases by Age in Illinois, 2006

80 60 40 20

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-59 yr >59 yr Year

Figure 28. H. influenzae Cases in Illinois by Month, 2006

20 15 10 5

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

40 Listeriosis

Background Listeriosis is caused by infection with Listeria monocytogenes, which is common in the environment. It is a that can cause in immunocompromised persons and meningoencephalitis and febrile in immunocompetent persons. Febrile gastroenteritis is considered to be uncommon. A study in Canada identified only 17 cases of L. monocytogenes in 8,000 stool specimens submitted for diagnosis of a diarrheal illness. Patients receiving antineoplastic therapy are more susceptible to listeriosis. Bloodstream infection, sepsis and meningitis are typical clinical presentations. Listeriosis has the highest case fatality rate of any foodborne illness. Pregnant women whose gastrointestinal tracts become colonized with the after they eat contaminated foods can transmit the organism to the fetus or can contaminate the baby’s skin or respiratory tract during childbirth. The median incubation period is three weeks, which makes identifying a suspect food vehicle difficult. L. monocytogenes is found frequently in nature and can be cultured from foods and the environment, which makes typing of isolates from patients and suspected food items important. The majority of isolates from cases are 1/2 a, 1/2 b or 4b. Pulse field gel electrophoresis can be used to further discriminate between isolates. Contaminated food vehicles often identified in outbreaks of listeriosis in the United States include unpasteurized dairy products. However, other vehicles have been identified. L. monocytogenes can resist salt, heat, nitrite and acidity better than many other organisms. It also can survive and multiply at cold temperatures. Refrigerators at 40° F or below are best for reducing the potential for listeriosis. Of the 10 diseases/syndromes under active FoodNet surveillance (those caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), listeriosis comprised 138 of 17,252 (0.8 percent) of the reported infections in 2006. Incidence rates ranged from 0.1 to 0.5 per 100,000 at the 10 sites with an overall incidence of cases of 0.3 per 100,000 population. In 2006, 884 cases of listeriosis were reported to CDC from 48 states and territories.

Case definition Illinois uses the CDC case definition for Listeria cases: a clinically compatible history (stillbirth, listeriosis of the newborn, meningitis, bacteremia or localized infection) and isolation of L. monocytogenes from a normally sterile site. In the setting of miscarriage or stillbirth, isolation of L. monocytogenes from placental or fetal tissue is adequate as laboratory confirmation. A maternal-child pair will only be counted as one maternal case.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 31 total (five were described as cases of meningitis). All cases were confirmed. The five-year median is 24 (Figure 29). The 2006 incidence for all reported listeriosis was 0.24 per 100,000 population.

41 • Age - Cases ranged in age from younger than 1 year to 91 years of age; 77 percent of cases were older than 59 years of age. • Seasonal distribution – Cases occurred from January through December. • Gender – Fifty-two percent of cases were female. • Race/ethnicity - Seventy-nine percent of the cases were white, 14 percent were African American and 7 percent were other races. Nine percent reported Hispanic ethnicity. • Geographic location – Eleven of the 31 cases were reported from Cook County. Ten counties reported cases. • Diagnosis - The site of Listeria isolation was identified as follows: blood (25), cerebrospinal fluid (two), blood and CSF (one), peritoneal fluid (one), fetus (one and brain (one). CDC typed seven isolates. They were typed as 4b (three), 1 /2 a (three) and 1 / 2 b (one). • Underlying conditions – Twenty-five of 28 (89 percent) cases with information available on immunosuppressive conditions reported an immunosuppressive condition. These included pregnancy, cancer, diabetes mellitus, renal disease/dialysis or steroid therapy. • Clinical – All cases were hospitalized. One case had a spontaneous abortion. Two of 25 cases with information on mortality died. The fatal cases were 16 and 91 years of age. • Epidemiology – Five cases resided in a residential facility. • Reporting – Ninety percent of cases were reported by infection control professionals and 10 percent by laboratory staff. • There were no outbreaks of reported listeriosis in Illinois in 2006.

Summary In 2006, Illinois recorded 31 listeriosis cases; 77 percent of the cases were older than 59 years of age. The incidence rate (0.24) was within the range described by CDC’s FoodNet sites in 2006 (0.1-0.5 per 100,000).

Figure 29. Listeriosis Cases in Illinois, 2001-2006

40 32 31 30 24 23 24 24 20 10

Number of cases of Number 0 2001 2002 2003 2004 2005 2006 Year

42 Invasive Neisseria meningitidis

Background N. meningitidis is an important cause of bacterial meningitis and septicemia in the world. The bacteria that causes , N. meningitidis, is carried in the by about 5 percent to 10 percent of the population. The organism is transmitted by direct contact with respiratory droplets from the nose and throat of an infected person. Most patients acquire infection from an during face-to-face contact including coughing, sneezing and kissing and the sharing of drinks, foods and cigarettes. The incubation period ranges from two to 10 days and is usually three to four days. Meningococcal disease is an acute bacterial disease that may be characterized by fever, headache, stiff neck, delirium and, often, a rash and vomiting. It presents as meningitis in 80 percent to 85 percent of cases. Septicemia also can result from infection with N. meningitidis. The overall case fatality rate is between 10 percent and 14 percent. Eleven percent to 19 percent of survivors have permanent sequelae. Carriage of the meningococcus organism is transient and the level of carriage does not predict the course of an outbreak. Less than 1 percent of exposed persons who become infected develop invasive disease. Rates are highest in infants.. Among those aged 11 to 19 years, 75 percent of cases are caused by A, C, Y, W-135. The majority of cases in infants are group B. Antimicrobial chemoprophylaxis is used for close contacts of cases. Only close contacts should be given chemoprophylaxis due to concerns about . Vaccination can be used as an adjunct measure to protect against A, C, Y and W135 serogroups. A that protects against these serogroups was licensed in the United States in 1982. It is given routinely to military recruits and to certain travelers. A second vaccine using conjugate technology was approved in early 2005 for protection against the same four serotypes among persons aged 2 to 55 years. A against serogroup B has been used successfully in some settings overseas. It has not been approved for use in the United States. Vaccination campaigns are used in highly selected situations. One vaccination campaign occurred in New York City after 23 cases of N. meningitidis group C were identified. Eighty-three percent of cases with the same PFGE pattern over a one-year period were in persons using illicit drugs. One control measure was use of vaccination in the community at risk with 2,763 persons receiving vaccine. In May 2005, CDC recommended routine vaccination with meningococcal vaccine for adolescents, college freshman living in dormitories, and others at high risk for meningococcal disease. There may be a small risk of Guillain-Barre syndrome following meningococcal vaccination but this risk must be evaluated further. A national survey in 2006 of adolescents aged 13 to 17 identified that meningococcal vaccine had been received by 12 percent of adolescents nationally. In 2006, 1,194 cases were reported in the United States. In the CDC Active Bacterial Core Surveillance sites in 2006, 46 percent of cases presented with meningitis. The percent of cases with each serogroup was Y (40 percent), B (28 percent), C (28 percent) and other (7 percent). The national estimate for invasive disease is 0.30 per 100,000 for 2006. Completeness of reporting is important because close contacts to N. meningitidis cases need chemoprophylaxis. A study in Maine from 2001 to 2006 comparing reported cases and hospital discharge data showed that 98 percent of cases were reported.

43

Case definition The case definition for a confirmed case of meningococcal disease is a clinically compatible case with N. meningitidis isolated from a normally sterile site or from skin scrapings of purpuric lesions. The case definition for a probable case is a compatible illness with PCR positive from a normally sterile site or evidence of N. meningitidis from latex agglutination of CSF or positive immunohistochemistry on formalin fixed tissue. A suspect case has clinical purpura fulminans in absence of positive blood culture or clinically compatible case with gram negative diplococci from a normally sterile site. Suspect cases are not counted as official cases in the case count for Illinois.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 46 (incidence of 0.4 per 100,000) (five-year median = 57) (Figure 30). Forty-two cases were confirmed and four were probable. Three cases were reported to be in college students and five cases were reported to be day care attendees. One case resided in a homeless shelter. • Age - The age distribution of reported meningococcal disease is shown in Figure 31. Mean age of cases was 39 (range: younger than 1 year to 86 years of age) • Gender – Forty-four percent of cases with gender information were female. • Race/ethnicity – Twenty-six percent of cases were African American and 71 percent were white; 18 percent were Hispanic. • Seasonal distribution - Meningococcal disease occurred throughout 2006 with increases in the winter (Figure 32). • Geographic location – Forty-eight percent of reported cases were from Cook County. • Presentation – For 44 cases with case reports, the presentation of illness was bacteremia (52 percent), meningitis (43 percent), pneumonia (2 percent) and septic arthritis (2 percent). • Diagnosis - The organism was isolated from blood only (27 cases), CSF only (nine), blood and CSF (six) and joint fluid only (one). For three probable cases, diagnostic testing included identification of gram negative diplococci (two) and antigen testing of CSF (one). Serogrouping was performed on isolates from 40 (87 percent) of cases. In cases where typing was done, the serogroups identified were Y (37 percent), C (17 percent), B (32 percent), W-135 (5 percent), Z (2 percent) and nontypable (5 percent) (Figure 33). • Treatment – Forty-one of 45 (91 percent) of individuals with information available were hospitalized. • Mortality - The case fatality rate was 20 percent for 30 patients where the outcome of infection was known. Ages of the six fatal cases were 13,17, 44, 55, 69, and 86 years of age. • Reporting – Nineteen cases were reported by infection control professionals. • Clusters – None reported. No clusters requiring a vaccination campaign occurred in 2006.

44 Summary The number of N. meningitidis cases reported in Illinois in 2006 (46) was lower than the five-year median (57 cases). The incidence in Illinois (0.4 per 100,000) was higher than the national estimates of incidence for 2006 (0.3 per 100,000). Eighty-seven percent of isolates were serogrouped. Serogroup Y was the most common serogroup reported.

Suggested readings CDC. 2007. Active bacterial core surveillance report, Emerging Infections Program network, Neisseria meningitidis, 2006. Available via the Internet: http://www.cdc.gov/ncidod/dbmd/abcs/survreports/mening06.pdf. Clarke, C. and Mallonee, S. State-based surveillance to determine trends in meningococcal disease. Pub Health Reports 2009; 124:280-87. Jain, N. National vaccination coverage among adolescents aged 13-17 years- United States, 2006. MMWR 2007;56 (34): 885-888. Rea, V. Completeness and timeliness of reporting of meningococcal disease – Maine, 2001-2006. MMWR 2009; 58(7):169-172. Weiss, D., et. al. Epidemiologic investigation and targeted vaccination initiative in response to an outbreak of meningococcal disease among illicit drug users in Brooklyn, New York. Clin Inf Dis 2009;48:894-901.

Figure 30. Meningococcal Disease in Illinois, 2001-2006

100 88 73 80 57 60 46 36 34 40 20

Number of cases of Number 0 2001 2002 2003 2004 2005 2006 Year

45 Figure 31. N. meningitidis Cases by Age in Illinois, 2006

15

10

5

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-59 yr >59 yr Year

Figure 32. N. meningitidis Cases in Illinois by Month, 2006

6

4

2

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

Figure 33. N. meningitidis Cases in Illinois by Serogroup, 1993-2006

80 B 60 C 40 Y 20 Other

Number of cases 0 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year

46 Invasive Group B Streptococcus

Background Group B streptococcus and E. coli cause most cases of sepsis in infants. Around 10 percent to 35 percent of pregnant women may be colonized with group B streptococcus at the time of labor placing them at risk for transmitting the disease to their infants. Group B streptococcus infections are due to Streptococcus agalactiae and cause disease and death in newborns and morbidity in peripartum women and nonpregnant adults with chronic medical conditions. Early-onset disease of neonates (less than seven days) may consist of sepsis, respiratory distress, apnea, shock, pneumonia and meningitis. The infection is acquired during delivery or in utero. Early-onset disease is caused by maternal group B streptococcus carriage. Risk factors for early-onset group B streptococcus sepsis (that occur within 72 hours of life) include fever in the mother during labor, preterm delivery, membrane rupture greater than 18 hours before delivery and a mother with a previous infant with group B streptococcus. Infants acquire infection through aspiration of contaminated amniotic fluid or during passage through the birth canal. Late-onset disease (seven days to several months) is characterized by sepsis and meningitis and is acquired by person-to-person contact. Only about 50 percent of late- onset disease cases have been shown to be of maternal origin.

Case definition A confirmed case of invasive group B streptococcus disease is defined as isolation of GBS from a normally sterile site (e.g., blood or cerebrospinal fluid). A probable case is defined as a person who is latex agglutination positive for group B streptococcus from a sterile site. Only cases younger than 3 months of age were required to be reported in Illinois in 2006.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 89; 65 cases were less than 3 months of age. Twenty-four cases were in older age groups. • Age – Thirty-four of 65 (52 percent) of cases were younger than 3 months of age. Only cases younger than three months of age are reportable. • Gender – Thirty-four of 65 (52 percent) of all cases younger than 3 months were female. Sixty-two percent of those older than three months were female. • Race/ethnicity – Forty-five percent of all cases younger than three months were white and 42 percent were African American; 27 percent were Hispanic. There was a significantly higher proportion of African Americans with GBS as compared to their representation in the Illinois population. • Seasonal variation – Thirty-eight of 65 (58 percent) of cases younger than 3 months of age had onsets from August to December. • Diagnosis – All reported cases (all ages) were confirmed by a positive culture. The organism was isolated from blood (71 cases), CSF (12 cases), blood and CSF (four cases) and other or unknown sites (one case). • Case outcome – Sixty-three of 65 cases (97 percent) younger than 3 months of age were hospitalized; two cases were known to be fatal. For those older than 3 months of age, 20 of 23 cases were hospitalized and two fatalities were among

47 this age group. • Reporter – Eighty of the 89 cases were reported by infection control professionals

Summary Cases of invasive group B streptococcal disease in newborns can be prevented if the appropriate guidelines are followed by health care providers. Eighty-nine cases of group B streptococcus disease were reported in Illinois, the majority in those younger than 3 months of age. Although only group B streptococcal disease in those younger than 3 months of age is reportable, voluntary reporting of invasive group B streptococcus disease in persons older than 3 months of age occurs.

48 Cholera Background Cholera is a bacterial enteric disease that causes sudden onset of severe watery diarrhea and also may cause vomiting. Rapid and renal failure can occur. serogroups 01 and 0139 are associated with cholera. Serogroup 01 has two biotypes: classical and El Tor. V. cholerae O139 is present in South East Asia. Cholera is transmitted by ingestion of contaminated food or water. The incubation period is usually two to three days. The U.S. Gulf Coast can be a source of the cholera organism. Epidemics of cholera are associated with consumption of contaminated water, poor hygiene, poor sanitation and crowded living conditions. Cholera is one of three diseases requiring international notification to the World Health Organization. All domestically acquired cases had consumed seafood. Vaccines are available and are administered to travelers to countries with cholera.

Case definition A confirmed case of cholera in Illinois is a clinically compatible case (diarrhea and/or vomiting) that is laboratory confirmed. Laboratory confirmation is through isolation of toxigenic V. cholerae 01 or 0139 from stool or vomitus or serologic evidence of cholera.

Descriptive Epidemiology One cholera case was reported in Illinois in 2006. The case was a 58-year old male with V. cholerae serotype 01, type inaba, biotype El Tor and was positive for cholera toxin by PCR. The isolate was resistant to trimethoprin-sulfa methoxazol, furazolindone, nalidixic acid, sulfisoxazol, and streptomycin. The patient traveled to India for business before becoming ill. He was not vaccinated for cholera. While in India he prepared local food and drank local water. He was not admitted to a hospital and survived.

Summary One case of cholera in Illinois occurred in 2006. Cholera is reported infrequently and is usually associated with travel overseas. Illinois was one of four states reporting cases in 2006.

47 Cryptosporidiosis

Background Cryptosporidiosis is primarily a gastrointestinal disease that affects humans and 45 other species. Disease results from infection with Cryptosporidium species oocysts. There are 12 species recognized. Two species, C. hominis (previously known as C. parvum genotype 1) and C. parvum (previously known as C. parvum, genotype 2) are the most important human pathogens. C. hominis is largely restricted to humans and C. parvum to a range of species including sheep, cattle and humans. The organism is shed in the feces in the form of an oocyst, which has a hard shell to protect it from the environment. Oocysts are immediately infective upon excretion by an infected host and can be shed for up to two weeks or longer in immunocompetent humans. Infection is spread through person-to-person transmission, from direct contact with animals and by swimming in contaminated water. Approximately one to three percent of the general population may be excreting oocysts. The incubation period is an average of seven days (range is one to 12 days). Predominant symptoms include profuse and watery diarrhea accompanied by abdominal cramping. Infection in immunocompetent people lasts one to two weeks. Persons at risk for more severe infection include young children, pregnant women or persons with weakened immune systems. Oocysts of cryptosporidia can be found in many types of water including untreated surface water, filtered swimming pool water and even from chlorine-treated or filtered drinking water. The minimum level of detectable oocysts that pose a public health threat in domestic water supplies is not known. Outbreaks have occurred due to person-to- person and waterborne spread. Cryptosporidium is the leading cause of reported outbreaks of gastroenteritis linked to treated swimming venues. Of the 10 diseases under active surveillance in FoodNet sites (illnesses caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), Cryptosporidium comprised 5 percent of the reported infections. There was a preliminary incidence rate of 1.9 per 100,000 for Cryptosporidium and incidence ranged from 0.8 to 4.7 at the ten FoodNet sites in 2006. In 2006, 6,071 confirmed cryptosporidiosis cases were reported to CDC through NETSS. The number of cases was highest in those one to nine years of age. A tenfold increase occurred from summer to fall. Important features of cryptosporidiosis include: 1) waterborne outbreaks are typical, 2) oocysts are resistant to commonly used disinfectants 3) transmission can occur by direct fecal-oral contact, 4) as few as 10 to 100 oocysts can cause infection, 5) oocysts are infectious upon excretion and 6) asymptomatic infections occur. Prevention of outbreaks includes advising ill persons to wash hands with soap and water after using the toilet and before eating or preparing food, to avoid swimming in recreational water during illness and for at least two weeks after diarrhea stops and to avoid fecal exposure during sexual activity. Environmental control measures, such as hyperchlorination, may be needed when outbreaks in recreational water facilities are discovered. The first treatment for cryptosporidiosis in the United States was introduced in 2006 ().

Case definition A confirmed symptomatic case of cryptosporidiosis in Illinois is laboratory confirmed (demonstration of Cryptosporidium oocysts in stool by microscopic 48 examination, or demonstration of Cryptosporidium in intestinal fluid or small bowel biopsy specimens, or demonstration of Cryptosporidium oocyte or sporozite by a specific immunodiagnostic test such as ELISA or by PCR techniques or demonstration of reproductive stages in tissue preparations) and is associated with one of the following symptoms: diarrhea, abdominal , loss of appetite, low-grade fever, nausea or vomiting. A confirmed asymptomatic case is a laboratory confirmed case associated with none of the symptoms described above.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 258 (five-year median = 160; see Figure 29). Fifty–three cases were probable; the rest were confirmed. The incidence rate was 2 per 100,000. CDC only counted 204 confirmed cases for Illinois for 2006. • Age - Mean age for all 2006 cases was 35 years. Age distribution of cases is shown in Figure 30. • Gender – Forty-seven percent were male. • Race/ethnicity – Eighty-two percent were white, 11 percent were African American, and 6 percent were other races; 11 percent were Hispanic. • Seasonal variation - Cases peaked in July through September (Figure 31). • Clinical – Eight cases were reported to be asymptomatic. Symptoms included diarrhea (95 percent), fever (45 percent) and vomiting (56 percent); 22 percent were hospitalized, no cases were fatal. • Geographic location – The three counties with the highest incidence of cryptosporidiosis were: Tazewell (58 per 100,000), Carroll (18 per 100,000) and DeKalb (18 per 100,000). An outbreak was reported in Tazewell County that resulted in a high incidence rate. • Reporting – Ninety-two cases were reported by laboratory staff and 83 by infection control professionals. • Risk factors – o Contact with animals – Contact with animals was reported by 103 cases, including 10 who had contact with cattle. o Travel - Nineteen persons reported travel outside the United States including travel to Mexico (six) and China (four). Thirty–two cases traveled out-of-state but within the United States including ten who traveled to Wisconsin. Six of the ten cases who traveled to Wisconsin visited the Wisconsin Dells area, a popular tourist destination that has many recreational water venues. o Swimming - Seventy-one of 183 (39 percent) of the cases reported swimming in chlorinated water. Twenty-nine of 181 (16 percent) reported swimming in non- chlorinated water. o Well water exposure - Fifteen of 179 cases (8 percent) reported drinking private well water; o Day care contact – Twenty-five of 183 cases (14 percent) reported contact with a daycare o Residential facility - Eighteen of 176 cases (10 percent) had contact with a residential facility. • Outbreaks: In 2006, three recreational water outbreaks and one community outbreak occurred in Illinois; three outbreaks are discussed in further detail in the 49 foodborne and waterborne disease outbreak section. In INEDSS, 56 individual cases were specified as outbreak-related. In the outbreak reports, 65 cases were listed as linked to waterborne outbreaks. In the community outbreak, 17 persons in a neighborhood became ill with diarrhea and tested positive for Cryptosporidium. The source was not identified. All of the children shared pools and sandboxes.

Summary The number of reported cases of cryptosporidiosis in 2006 was higher than the number reported in 2005. Four outbreaks were reported in 2006. The incidence was high in Tazewell County due to an outbreak in a pool. Most cases in 2006 occurred in the late summer and early fall. The incidence of reported cryptosporidiosis in Illinois (2 per 100,000) was the same as the preliminary incidence reported by FoodNet.

Figure 29. Cryptosporidiosis Cases in Illinois, 2001-2006

600 483

400 257 161 160 200 121 102

Number of cases 0 2001 2002 2003 2004 2005 2006 Year

Figure 30. Age Distribution of Cryptosporidiosis Cases in Illinois, 2006

80 60 40 20

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Year

Figure 31. Cryptosporidiosis Cases in Illinois by Month, 2006

150

100 Outbreak 50 Non-outbreak

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Onset

50 Cyclosporiasis

Background Cyclosporiasis is caused by a protozoal organism, Cyclospora cayatensis. Clinical illness consists of watery diarrhea and abdominal cramping. Diarrhea is usually self-limiting but may be prolonged. The median incubation period is seven days. Transmission to persons is usually through drinking or swimming in contaminated water. Several international outbreaks have involved consumption of raspberries from Guatemala. Basil and lettuce also have been implicated in transmission. In 2006, 137 confirmed cyclosporiasis cases were reported to CDC through NETSS. Florida reported the most cases in 2006. Of the 10 diseases under active surveillance in FoodNet sites (illnesses caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), Cyclospora comprised 41 of 17,252 (0.23 percent) of the reported infections in preliminary data from 2006. Data from 2006 showed the incidence rate was 0.09 per 100,000 for Cyclospora and ranged from 0 to 0.3 at the ten FoodNet sites with preliminary data.

Case definition Laboratory confirmation is the finding of C. cayatensis oocysts in stool by microscopic examination or in intestinal fluid or small bowel biopsy specimens; or demonstration of sporulation or PCR positive in stool, duodenal/jejunal aspirates or small bowel biopsy specimens. CDC has two case classifications: Confirmed, symptomatic - laboratory confirmed with clinically compatible illness. Confirmed, asymptomatic - laboratory confirmed with no symptoms.

Descriptive epidemiology Number of cases reported in Illinois in 2006 – One case, which was confirmed, was reported in July from Cook County.

Summary No outbreaks of cyclosporiasis were reported in Illinois in 2006.

51 Ehrlichiosis

Background Ehrlichia are bacteria that infect a wide variety of animals and are transmitted by tick bites. Four Ehrlichia pathogens have been identified in the United States: E. chaffeensis (causing human monocytic ehrlichiosis (HME)), Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) causing human granulocytic (HGA), E. canis and E. ewingii. Only one person with E. canis has been reported and the person was not clinically ill. E. chaffeensis and E. canis mainly invade the monocyte, and the disease caused by these organisms is termed HME. A. phagocytophilum and E. ewingii invade mainly the granulocytes and the disease is referred to as granulocytic ehrlichiosis. Both HGA and HME are zoonotic diseases requiring an arthropod vector and a mammalian reservoir. A specific history of a tick bite can be elicited in about 68 percent of ehrlichiosis cases. E. chaffeensis, which causes HME, is transmitted to humans primarily by the lone star tick, A. americanum. The white-tailed deer is a major host for this tick and acts as a for E. chaffeensis. Cases of HME are most commonly reported from Missouri, Oklahoma, Tennessee, Arkansas, and Maryland. The average reported annual incidence of HME from 2001 to 2002 was 0.7 cases per million population. The blacklegged tick (Ixodes scapularis) is the vector of A. phagocytophilum which causes HGA in New England, the North Central United States and Europe. HGA is more frequently reported than HME with an average incidence of 1.6 cases per million from 2001 to 2002. States with the highest incidence were Rhode Island, Minnesota, Connecticut, New York and Maryland. E. ewingii can be carried by Ambylomma americanum. Cases of human granulocytic ehrlichiosis caused by E. ewingii have been reported primarily in immunocompromised patients from Missouri, Oklahoma and Tennessee. Infection may also occur in dogs. Both HME and HGA result in similar symptoms: fever, headache and myalgia. Cases also may have low platelets, low white blood cells and increased liver enzymes. Rash occurs in approximately one third of HME patients and is rare in patients with HGA or E. ewingii. In 25 percent of HME cases, respiratory tract involvement occurs, and in 20 percent of cases central nervous system disease occurs. More than 40 percent of HME cases require hospitalization, and severe complications can include meningoencephalitis, acute respiratory distress syndrome, toxic shock like syndrome, renal failure, coagulopathy and multiorgan failure. Serious outcomes can occur with HGA in persons with impaired immune systems. These Ehrlichia organisms can form clusters of organisms called morulae, in the white blood cells. The case fatality rate has been reported as 5 percent in HME and 10 percent in HGE. All symptomatic cases of HGA should be treated. Fever should be reduced within 48 hours of the initiation of antimicrobial therapy. In 2006, 646 HGA, 578 HME and 231 other or unknown types of ehrlichiosis cases were reported to CDC.

Case definitions HME A clinically compatible illness with demonstration of a four-fold change in antibody titer to E. chaffeensis antigen by IFA in paired serum or positive PCR and confirmation of E. chaffeensis DNA, or identification of morulae in leukocytes and a positive IFA titer to 52 E. chaffeensis antigen, or immunostaining of E. chaffeensis antigen in a biopsy or autopsy specimen or positive culture for E. chaffeensis in a clinical specimen.

HGE A clinically compatible illness with demonstration of demonstration of a four-fold rise in antibody titer to E. phagocytophila antigen by IFA in paired serum or positive PCR and confirmation of E. phagocytophila DNA, or identification of morulae in leukocytes and a positive IFA titer to E. phagocytophila antigen, or immunostaining of E. phagocytophila antigen in a biopsy or autopsy specimen or positive culture for E. phagocytophila in a clinical specimen.

Ehrlichiosis, human, other or unspecified agent A clinically compatible illness with demonstration of a four-fold change in antibody titer to more than one Ehrlichia species by IFA in paired serum samples, in which a dominant reactivity cannot be established, or identification of Ehrlichia species other than E. chaffeensis or E. phagocytophila by PCR, immunostaining or culture.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 32; Twenty-five were HME, six were HGA and one was of unknown type. All HGA cases were probable. Three HME cases were confirmed and 22 were probable. At the time when case reports were due to CDC, Illinois was recorded as reporting 23 HME, six HGA and three other or unknown ehrlichia cases for Illinois. We will use the Illinois numbers for the information listed below. • Age - Cases ranged in age from 11 to 73 years of age (mean= 49 years). • Gender - Nineteen cases were male and 13 were female. • Race/ethnicity – All but one case was white; one was Hispanic. • Geographic distribution – o Two HGA cases resided in Stephenson County, and one each in Boone, Jackson, Marion, and Sangamon counties. Four HGA cases were exposed in-state: two in Stephenson county and one each in Marion and Franklin counties. Two cases reported tick exposure in Minnesota. o The HME cases resided in Williamson (four cases), Jackson (three cases), Perry (two cases), Saline (two cases) and Cook (two cases) counties. Additionally, one HME case resided in each of Clay, Crawford, Franklin, Greene, Jasper, Pike, Pope, St. Clair and Union counties. The HME cases reported exposures in Williamson (three cases), Marion (two cases), Jackson (two cases) and Cook (two cases) counties. Also, one HME case reported exposure in each of Pope, Randolph, Franklin, Shelby, Perry, Union, Saline, Jasper and Greene counties. Four cases reported out-of- state exposures and one case reported both an in-state and out-of-state exposure. Two reported unknown exposure locations. o An ehrlichia case, unknown type, had exposure in Adams County. • Seasonal variation – Most onsets occurred between June and August (Figure 32). • Diagnostic testing – The cases of HGA were diagnosed by serologic testing (four cases), morulae in neutrophils (one case), and smear positive (one case). The cases of HME were diagnosed with antibody titers (23) and PCR (two).

53 • Outcomes – Seventy-two percent of cases were hospitalized. There were no fatalities. • Reporting – Seventy-two percent of cases were reported by laboratories. • Past incidence - Reported cases of ehrlichiosis in Illinois in past years have been infrequent : 1992 (none), 1993 (none), 1994 (one), 1995 (four), 1996 (four), 1997 (none), 1998 (two), 1999 (five), 2000 (one), 2001 (seven), 2002 (six), 2003 (nine), 2004 (12) and 2005 (seven).

Summary Thirty-two ehrlichiosis cases were reported in Illinois in 2006. Sites of tick exposure for HME cases were primarily in southern Illinois. Most onsets were from June through August.

Suggested readings Wormser, G.P. et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and : Clinical practice guidelines by the Infectious Disease society of America. CID 2006;43:1089-134).

Figure 32. Ehrlichiosis Cases in Illinois by Month, 2006

15

10

5

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Onset

54 Shiga-toxin producing E. coli, enterotoxigenic E. coli, enteropathogenic E. coli)

Background Strains of Escherichia coli that cause diarrhea are classified into pathotypes. Shiga toxin producing E. coli (STEC) may cause bloody diarrhea and hemolytic uremic syndrome because they produce Shiga toxins. Enteropathogenic E. coli (EPEC) lack Shiga toxins and cause nonspecific diarrhea in infants in less-developed countries. Enterotoxigenic E. coli outbreaks are rarely reported in the United States. E. coli O157:H7 is one type of STEC and was first recognized as a cause of human illness and associated with ground beef in 1982. E. coli O157:H7 causes primarily a diarrheal illness. The infectious dose is thought to be low due to evidence of person-to-person transmission and recreational water exposure transmission. The incubation period is from three to eight days with an average of three to four days. Occasionally, longer incubation periods have been reported. Infection with E. coli O157:H7 produces symptoms that range from mild to bloody diarrhea and that may progress to hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP); three to five percent of HUS cases are fatal. The term HUS is used to describe acute renal failure accompanied by non-immune hemolytic anemia and thrombocytopenia. It occurs most frequently in children less than five years of age after infection by an agent producing shiga toxin. The illness can involve the central nervous system (CNS), pancreas, heart and other organs. HUS can be caused by type 1 and STEC. The most common cause of HUS in the United States is E. coli O157:H7. E. coli O157:H7 is transmitted through consumption of contaminated food or beverage, person-to-person contact or swimming in contaminated recreational water. Three large multi-state outbreaks occurred in the fall of 2006 caused by contaminated spinach and lettuce. In one outbreak, consumption of fresh spinach was linked to E. coli O157:H7 in a multi-state outbreak. Twenty six states reported 183 cases. Onsets of illness were from August 19 to September 5. Two Illinois residents were affected. Another outbreak in California in 2006 was linked to consumption of raw milk. During 2006, 4,432 STEC cases were reported from 49 states. Of the nationally reported cases in 2002 in six states, the median interval from onset of symptoms to PFGE analysis was 15 days for E. coli O157:H7. The median interval from onset of symptoms to interview was 12 days for E. coli O157:H7. Of the 10 diseases under active surveillance in the FoodNet sites (illnesses caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), E. coli O157:H7 was responsible for 590 of 17,252 (3 percent) of the reported infections in 2006 data. STEC non-O157 were responsible for 209 of 17,252 (1 percent) of the reported infections. The preliminary incidence rate for E. coli O157:H7 was 1.3 per 100,000 and ranged from 0.45 to 2.9 per 100,000 at the ten FoodNet sites. The preliminary incidence rate for STEC non-O157 was 0.5. On STEC non-O157, the following O antigens were identified: O26 (28 percent), O103 (24 percent) and O111 (15 percent). CDC recommends that all bloody diarrheal stools be routinely cultured for E. coli O157:H7. Rapid tests also are available to directly detect shiga toxin in stool specimens. Specimens testing positive should be cultured to identify which organism (E. coli or Shigella) produced the shiga toxin. Broth culture media or specimens in which shiga toxin has been detected should be cultured for E. coli or submitted to the state public health laboratory for E. coli isolation. 55 Pulsed-field gel electrophoresis (PFGE) is done routinely in Illinois on E. coli O157:H7 isolates that are submitted to the state laboratory. Epidemiologic investigation into a cluster of cases should occur after finding a match by two enzyme PFGE. Single enzyme analysis is insufficient to determine whether isolates and cases are truly related. Enterotoxigenic E. coli is believed to be a common cause of traveler’s diarrhea. United States residents who travel overseas may return to the United States with ETEC. Enterotoxigenic E. coli is not identified by routine stool culture methods. Prevention measures for enteric E. coli infections include cooking food thoroughly, prompt refrigeration of foods and separation of cooked and raw foods. are contraindicated for treatment of E. coli O157:H7 infections; this treatment leads to release of toxin as bacteria die and increased risk for development of Hemolytic Uremic syndrome (HUS). Food safety practices that can decrease risk of E. coli O157:H7 from ground beef include thawing frozen ground beef in the refrigerator, not at room temperature, and cooking to a temperature of 160° F. Kitchen items in contact with raw ground beef should be washed thoroughly before reusing. Consumers must also be responsible for protecting themselves when in contact with farm animals that may carry STEC.

Case definition The case definition for a confirmed case of E. coli O157:H7 used in Illinois is a clinically compatible illness with isolation of E. coli O157:H7 from a stool specimen or E. coli O157 organisms that are laboratory confirmed as producing shiga toxin. E. coli isolated in stool from a person with clinically compatible illness that produce shiga toxin but are not identified as O157 is also reportable as shiga toxin producing E. coli, non- O157. A confirmed case of ETEC is a clinically compatible illness with laboratory confirmation of enterotoxigenic E. coli from stool. A confirmed case of enteropathogenic E. coli is a clinically compatible illness with laboratory confirmation of enteropathogenic E. coli from stool. A probable case of ETEC or enteropathogenic E. coli, or STEC is a clinically compatible case which is epidemiologically linked to cases but has not been laboratory confirmed.

Descriptive epidemiology Shiga-toxin producing E. coli, including E. coli O157:H7 • Number of cases reported in Illinois in 2006 – 125 (five-year median = 143) (see Figure 33). The incidence for E. coli O157:H7 in 2006 in Illinois was 0.77 cases per 100,000 population. Of these 125 cases, 96 were identified as E. coli O157:H7, two were identified as E. coli O157, H antigen unknown. Six were identified as STEC, non-O157 and 21 were STEC, shiga toxin positive but not cultured or serotyped. All but two cases were confirmed. CDC counted 104 STEC cases for Illinois for 2006. The 21 cases of STEC, shiga toxin positive but not cultured or serotyped were not counted in CDC numbers. Note: the information below is for E. coli O157:H7 cases only. • Age - Cases occurred in all age groups (mean = 37 years of age) (Figure 34). • Gender – Fifty-eight percent were female. • Race/ethnicity – Eighty eight percent were white, 6 percent were African American, and 17 percent were other races; 17 percent of cases were Hispanic. • Seasonal variation - The largest number of cases occurred in the months from July to September (51 percent of cases) (Figure 35).

56 • Geographic location – The county with the most cases was Cook (44 cases). • Clinical syndrome - Among those with culture-confirmed E. coli O157:H7 for which symptom information was available, 100 percent reported diarrhea, 82 percent reported bloody diarrhea, 45 percent reported vomiting and 45 percent reported fever; six cases (10 percent of patients for whom information was available) had HUS and no cases had thrombotic thrombocytopenic purpura (TTP). Two cases reportedly were put on dialysis. Sixty-three of 110 cases (57 percent) were hospitalized. One case was reported to be fatal. • Reporter – The most common reporters included infection control professionals (47 percent) and laboratories (38 percent). • Sensitive occupations - There were four cases involving healthcare workers, one involving a worker at a food service facility, one involving a worker at a daycare, and two involving workers in other sensitive occupations. • Outbreaks – Two foodborne outbreaks were reported in 2006 (see detailed description in the “Food and Waterborne Outbreaks” section). In INEDSS, six cases were reported to be associated with outbreaks.

Risk factors • Nine of 98 (9 percent) of the cases reported contact with a day care. • There were two cases attending or residing at a day care and six cases residing at a residential facility or school. • Travel – o Seventeen of 101 cases (17 percent) reported traveling to another state. . Wisconsin was the most common destination (five cases). o Four of 96 cases (4 percent) reported traveling to another country. Two traveled to Mexico, one to India and one to the Dominican Republic. • Animal Contact o Thirty-three of 83 cases (40 percent) reported contact with animals. Four cases had contact with cattle. • Well Water exposure - One of sixty cases reported drinking well water. • Recreational Water Exposure o Six cases of 97 (6 percent) reported swimming in non-chlorinated water. o Twenty of 91 cases (22 percent) reported swimming in chlorinated water. • Ground Beef Consumption – o Forty-seven of 77 cases (61 percent) reported consuming ground beef. o Eight of these cases reported consuming the ground beef undercooked.

ETEC • Number of cases reported in Illinois in 2006 - No cases or outbreaks of ETEC were reported.

Other types of reportable enteric E. coli There were no other types of E. coli infections reported in 2006.

Summary The incidence of infection with E. coli O157:H7 in 2006 was 0.77 cases per 100,000 population, which is lower than what was found in CDC’s FoodNet sites (1.3 per 100,000). 57 Most cases (51 percent) of E. coli O157:H7 occur in the months of July through September. Bloody diarrhea was reported by 82 percent of case individuals; 10 percent of patients reportedly had HUS diagnosed by a physician. Fifty-seven percent of cases were hospitalized. One Illinois case was fatal. Sixty-one percent of cases reported consuming ground beef.

Suggested readings Grant, J., et. al., Spinach-associated Escherichia coli O157:H7 outbreak, Utah and New Mexico, 2006. Emerg Inf Dis [serial on the Internet]. 2008 Oct. Available from http://www.cdc.gov/EID/content/14/10/1633.htm Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from http://www.cdc.gov/EID/content/14/2/311 Henderson, H. Direct and indirect zoonotic transmission of shiga toxin-producing Escherichia coli. JAVMA 2008; 232(6):848-859. Schneider, J. et. al., Escherichia coli O157:H7 infections in children associated with raw milk and raw colostrum from cows – California, 2006. MMWR 2008; 57(23):625- 630. State and local health departments. Ongoing multistate outbreak of Escherichia coli serotype O157:H7 infections associated with consumption of fresh spinach-United States, September 2006. MMWR 2006; 55(38):1045-6.

Figure 33. Shiga-toxin producing E. coli Cases in Illinois, 2001-2006

250 200 150 E. coli O157:H7 100 197 STEC, not further specified 173 102 96 50 124 122 41 29 Number of cases 0 2001 2002 2003 2004 2005 2006 Year

Figure 34. Age Distribution of Escherichia coli O157:H7 Cases in Illinois, 2006

30 20 10 0 Number of cases <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Year

58 Figure 35. Escherichia coli O157:H7 cases in Illinois by Month, 2006

25 20 15 10 5

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

59 Food and Waterborne outbreaks

Background The surveillance on food-related disease outbreaks (foodborne outbreaks) is significant in that food can act as a vehicle for transmission of pathogens or their by- products. Although many foodborne illnesses result in a few days of diarrhea, with additional symptoms such as fever, vomiting or muscle aches, others can have serious health effects such as hemolytic uremic syndrome, reactive arthritis, sepsis or Guillain Barré syndrome. Foodborne illness can be caused by microorganisms and their toxins, marine organisms and their toxins, fungi and chemical contaminants. There are three categories of organisms to consider in discussing the causes of foodborne illness: viruses, bacteria and parasites. For some viruses, such as hepatitis A or humans are the only reservoir. Prevention of foodborne illness depends heavily on food handlers and proper food handling practices. can occasionally cause foodborne outbreaks. Shellfish have been associated with hepatitis A virus, calicivirus and Vibrio spp. outbreaks. The use of gloves for food handlers is often recommended to decrease transmission of enteric pathogens. A study of glove use did not verify that glove wearers had less coliform bacteria on the food as compared to food handlers who did not wear gloves. It has been observed that food handlers wear the same pair of gloves for extended periods of time. Proper hygiene, such as keeping the environment clean, avoiding cross contamination, and proper can help prevent a large number of food and waterborne outbreaks. CDC estimates that in the 1990’s approximately 12 percent of foodborne outbreaks were linked to produce items. Bacteria comprise the largest category of foodborne agents. These include E. coli O157:H7, Salmonella and Listeria monocytogenes. Parasites like Trichinella in pork, Anasakis in raw fish or Cyclospora in raspberries also can cause foodborne illness. Some enteric pathogens, such as Campylobacter, Giardia and Shigella, rarely cause foodborne outbreaks. CDC’s Foodborne Disease Active Surveillance Network (FoodNet) is a system to collect information from seven states and selected counties in three states in the United States. The network provides stable and accurate national estimates of foodborne disease occurrences in the country. According to the Preliminary FoodNet Surveillance Report for 2006, there were a total of 17,252 laboratory-confirmed cases of infection in their surveillance system. The number of laboratory-confirmed causes was estimated as follows: Salmonella (15 per 100,000), Campylobacter (13 per 100,000), Shigella (6 per 100,000), Cryptosporidium (2 per 100,000), shiga-toxin producing E. coli (STEC) O157 (1 per 100,000), Yersinia (0.3 per 100,000), Vibrio (0.3 per 100,000), Listeria (0.3 per 100,000), STEC non-O157 (0.5 per 100,000), and Cyclospora (0.1 per 100,000). In 2006, 18 cryptosporidiosis outbreaks were reported in the United States. Prevention methods include education on not swimming with diarrhea, not swallowing pool water, practicing good hygiene and reporting fecal contamination to pool operators so they can disinfect appropriately. During recognized Cryptosporidium outbreaks, swimmers should be advised not to swim for two weeks after diarrhea was resolved.

60 A new foodborne and waterborne MS Access database was created at IDPH to record foodborne and waterborne outbreak information. Case definition A foodborne outbreak is an incident in which two or more persons (usually residing in separate households) experience the onset of a similar, acute illness (usually gastrointestinal) following ingestion of common food or drink. CDC has established case definitions for confirmed outbreaks and these are listed under the specific organisms in this outbreak section. For foodborne outbreaks, the number ill reflects those who meet a clinical case definition. For outbreaks where the etiologic agent was suspected and not confirmed, and the clinical syndrome matched the suspect etiologic agent but no laboratory confirmation was obtained, the suspect cause is ascribed to this etiologic agent. IDPH receives reports of potential foodborne outbreaks from many sources. Outbreak investigations, which are conducted by local health departments, may not result in a confirmed foodborne outbreak designation and will not be counted in the state totals. There are a number of reasons for this: lack of information, classification as person-person transmission or because the symptoms and incubation period do not clearly indicate a known foodborne pathogen.

Descriptive epidemiology The number of possible foodborne or waterborne outbreaks reported to IDPH by local health departments (LHDs) was 85 during 2006. The total for the year was 69 foodborne outbreaks that met the definition of an outbreak and were submitted to the Centers for Disease Control and Prevention (CDC). Of the 69 foodborne outbreaks, the etiology was confirmed in 23 foodborne, suspected in 35 outbreaks and unknown in 11 outbreaks. Four of the waterborne outbreaks were confirmed and one was unknown etiology. Five out of the 74 outbreaks were due to recreational water exposure. (Note: Drinking water outbreaks were not counted under recreational water outbreaks). In the year 2006, a total of 1,322 people were reported to have become ill as the result of the 69 foodborne outbreaks and 135 as a result of the five recreational water outbreaks. The mean number of cases ill was 20 per foodborne outbreak and 27 for waterborne outbreaks; the median number of cases ill was 11 per foodborne outbreak and 18 for waterborne outbreaks; the number of ill persons per outbreak ranged from 2 to 418 for foodborne and waterborne outbreaks combined. There were 65 persons hospitalized as a result of the foodborne outbreaks and one hospitalized due to waterborne outbreaks. There were no fatalities reported due to foodborne or waterborne outbreaks during the year 2006. Local health jurisdictions reporting foodborne outbreaks during the year 2006 were: Cook (36), Peoria (four) three each for the counties of DuPage, Kane, and Vermilion; two each for the counties of Clinton, Livingston, Pike, Will, and Winnebago; and one each for the counties of Coles, Henry, JoDaviess, Lake, Macon, Marshall, McLean, and Stephenson; and there were two multi-state foodborne outbreaks recorded. The waterborne outbreaks were reported from the counties of Winnebago (two), Lake (one), Logan (one), and Tazewell (one).

61 The 69 reported foodborne outbreaks occurred in the following months: January, six (9 percent); February, four (6 percent); March, eight (11 percent); April, seven (10 percent); May, six (9 percent); June, four (6 percent); July, six (9 percent); August, seven (10 percent); September, three (4 percent); October, four (6 percent); November, six (9 percent); and December, eight (11 percent). The recreational water outbreaks were in January, June, July and August (two). In the 69 foodborne outbreaks reported, the etiologic agent was determined to be due to bacterial agents (infection or intoxication), either suspect or confirmed, in 11 (14 percent) (Table 2 and 3). The bacterial pathogens were as follows: Salmonella spp. (four outbreaks), shiga toxin producing E. coli (two), Clostridium perfringens toxin (one), cereus/ S. aureus toxin (one), B. cereus/C perfringens toxin (one), S. aureus (one) and Campylobacter (one). The etiologic agent in 41 (59 percent) of the 69 foodborne outbreaks was suspected or confirmed to be caused by noroviruses. The IDPH laboratories were able to confirm 13 (32 percent) of these viral outbreaks. The remaining 28 (68 percent) outbreaks were classified as suspect norovirus outbreaks, largely based on symptoms, incubation and duration in the people who were affected. Two outbreaks were caused by parasitic agents and one was suspected to be due to excess calcium. Three of the recreational waterborne outbreaks were caused by Cryptosporidium, one was caused by Legionella and one had an unknown cause. Pools and water parks were the sites of exposure for the waterborne outbreaks. Although thorough investigations were conducted, there was inconclusive evidence to classify either suspect or confirm etiologic agents in 14 (20 percent) of the foodborne outbreaks and they were thus classified as etiology unknown. Food handlers were laboratory tested in nine of the foodborne outbreaks (13 percent). In six (67 percent) of the outbreaks food handlers were found to be positive for the etiologic agent implicated in the outbreak. Food handlers tested positive for norovirus in three outbreaks and Salmonella in three outbreaks. In outbreaks involving E. coli O157:H7, Salmonella serotype Berta, and a parasitic etiology, food handlers were negative. Environmental samples were taken in one foodborne outbreak and two waterborne outbreaks. In the E. coli O157:H7 foodborne outbreak samples were negative, as well as in the waterborne outbreaks tested for Cryptosporidium and fecal coliforms. Through either epidemiology, supportive information or food testing, 19 food or water items were implicated in outbreaks. In two outbreaks, chicken was implicated including chicken biryani and buffalo chicken wings. Vegetables were implicated in four outbreaks (salad in three and spinach in one). There were three outbreaks where pork was implicated, two outbreaks where beef was implicated (one corned beef and one beef burrito). Sandwiches were implicated in three outbreaks (one vegetable sandwich, one club sandwich and one turkey sandwich) and tortillas were implicated in one outbreak. Ice was implicated in one outbreak. Food items implicated in two other outbreaks included nachos with dip and peanut butter. The food causing illness in 50 foodborne outbreaks was unknown. Food was tested for pathogens in seven (10 percent) of the outbreaks. Positive foods were found in four (57 percent) of the outbreaks where samples were tested. The

62 responsible pathogens found were E. coli O157:H7, C. perfringens, S. aureus, and excess calcium. The site of food preparation in 69 foodborne outbreaks with available information were: restaurant, 47 (68 percent); caterer, seven (10 percent); banquet facility, two (4 percent); grocery, two (3 percent); private home, two (3 percent); commercial product, two (3 percent); lake side park, two, (3 percent) and farm, one (1 percent). Four (6 percent) had food preparation done at different sites (home, caterer, restaurant, church, banquet facility). The five recreational waterborne outbreaks were from entering pools and water parks. The site where the food was consumed, with 69 outbreaks were: restaurant, 34 (49 percent); home, 15 (22 percent); banquet facility, five (7 percent); church, three (4 percent); work, seven (10 percent); lake park, two (3 percent) and one each in hospital, school (1 percent each). In one outbreak (1 percent) food was consumed in multiple areas. The five recreational waterborne outbreaks had exposure to water at pools or water parks. In 28 (39 percent) of the 69 foodborne outbreaks, contributing factors were known. Contamination was noted as a contributing factor to 24 (86 percent) of the outbreaks, three outbreaks were related to proliferation/amplification factors (11 percent) and survival factors was responsible for one outbreak (4 percent).

Summary In 2006, Illinois recorded 69 foodborne and five waterborne outbreaks compared to a five-year median of 71. The most common site of food preparation in the reported outbreaks was restaurants. Improper food handling was the most commonly reported contributing factors to outbreaks. Both bacterial and viral agents were important causes of foodborne outbreaks. In the period 2002-2006, December had an increased number of outbreaks. Counts of reported foodborne and recreational waterborne outbreaks were highest in December followed by the month of May in the period, while the lowest counts were recorded during the months of July, followed by September then October.

Suggested readings Alden NB et al. Cryptosporidiosis outbreaks associated with recreational water use – Five states, 2006. MMWR 2007;56(29): 729-32.

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Table 2. FOODBORNE OUTBREAKS, CASES, AND DEATHS BY ETIOLOGY IN ILLINOIS, 2006 Outbreaks Cases Deaths Etiology# Count % Count % Count % Bacterial B. cereus/S. aureus ** 1 1 7 7 0 --- B. cereus/C. perfringens** 1 1 3 3 0 Campylobacter 1 1 18 17 0 --- Clostridium perfringens 1 1 8 7 0 --- Shiga-toxin producing Escherichia coli (O157:H7) 2 3 6 6 0 --- Salmonella 4 6 41 38 0 --- Staphylococcus aureus 1 1 23 22 0 --- Total Bacterial* 11 14 106 100 0 --- Chemicals Excess calcium 1 1 27 100 0 --- Total Chemical 1 1 27 100 0 --- Parasitic Other parasitic 2 3 62 100 0 --- Total Parasitic 2 3 62 100 0 --- Viral Norovirus 41 59 938 100 0 --- Total Viral 41 59 938 100 0 --- Confirmed etiology 23 33 Unknown etiology 14 20 189 Total 2006 69 100 1418 #Confirmed and suspected etiologies ** Suspected intoxication * Some outbreaks are suspected to be due to bacterial intoxication due to symptoms and incubation period but the specific agent was not known.

Table 3. FOODBORNE OUTBREAK PATHOGENS BY TESTING STATUS IN ILLINOIS, 2006 Confirmed Suspected Unknown Etiology Count % Count % Count % Bacterial B. cereus/S. aureus ** 0 --- 1 100 B. cereus/C. perfringens** 0 --- 1 100 Campylobacter 1 100 0 --- Clostridium perfringens 1 100 0 --- Shiga-toxin producing Escherichia coli (O157:H7) 2 100 0 --- Salmonella 4 100 0 --- Staphylococcus aureus 1 100 0 --- Total Bacterial 10 83 2 17 Chemicals Other chemical (calcium) 0 --- 1 100 Total Chemical 0 --- 1 100 Parasitic Other parasitic 0 --- 2 100

64 Total Parasitic 0 --- 2 100 Viral Norovirus 13 32 28 68 Total Viral 13 32 28 68 Total 2006 23 33 33 47 12 17 .

65 Specific types of foodborne outbreaks Bacillus cereus B. cereus causes foodborne illness through intoxication. There are two types of illness caused by B. cereus, depending on the enterotoxin elaborated by the organism. In one type, the incubation period is from one to six hours and symptoms last 12 hours or less. Almost all individuals experience vomiting and about one-third experience diarrhea. The illness is caused by a preformed enterotoxin. Rice has been associated with this type of B. cereus in past outbreaks. In the other type, the incubation period ranges from eight to 16 hours and symptoms last less than 24 hours. Diarrhea is a prominent feature but vomiting is absent. Foods associated with previous outbreaks include custards, cereals, and meat or vegetable dishes. The organism multiplies rapidly at room temperature and the spores can survive boiling.

Case definition Laboratory confirmation for B. cereus includes isolation of greater than 105 organisms per gram in properly handled food or isolation of the organism from two or more ill people and not from controls.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - None confirmed. There was one outbreak that may have been caused by either B. cereus or S. aureus intoxication as suggested by the clinical presentation and one outbreak in which the clinical picture suggested either B. cereus or C. perfringens intoxication, both were not confirmed. • Bacillus cereus had been identified as the cause of one foodborne outbreak in 2002, five outbreaks in 2003, and two in 2006; there were no outbreaks caused by B. cereus in 2004 or 2005.

Campylobacter species Campylobacter infection usually presents as bloody diarrhea, abdominal pain, nausea, vomiting and fever within two to five days of exposure. However, there are asymptomatic cases of campylobacteriosis. Cases are often associated with improper handling of raw poultry or eating raw or undercooked poultry.

Case definition Campylobacteriosis is diagnosed through isolation of the organism from any clinical specimen.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - One outbreak was confirmed and was linked to consumption of raw milk. o The source of raw milk involved in the Campylobacter jejuni outbreak was a farm selling raw milk illegally. Eighteen individuals became ill. Raw milk tested at the farm was negative for Campylobacter. The farm ceased

65 selling raw milk following this outbreak. • There was only one outbreak caused by Campylobacter in the previous 5 year period and that outbreak occurred in 2005.

Confirmed Outbreaks 1 Total number of ills 18 Average number of ills/outbreak 18 Number of cases hospitalized 0 Number of fatalities 0 Outbreak months January 1 Counties of outbreaks Coles 1 Food testing Yes, milk tested negative Environmental specimen tested none

Clostridium perfringens Another foodborne intoxication is caused by C. perfringens enterotoxin. Diarrhea is common but symptoms of vomiting and fever are usually absent. The incubation period is eight to 16 hours (usually 12 hours). The illness lasts one day or less. Almost all outbreaks are associated with the inadequate heating or reheating of meats or gravies, which allows the organism to multiply. The enterotoxin is heat-resistant.

Case definition There are three ways to establish laboratory confirmation of a C. perfringens outbreak: 1) isolation of greater than 105 organisms per gram of food that has been properly handled for testing, 2) demonstration of enterotoxin in the stool of two or more ills, or 3) isolation of greater than 106 organisms per gram in the stool of two or more ill persons.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 – One outbreak was confirmed; one outbreak was suspected to be due to either C. perfringens or B. cereus without laboratory confirmation. o An outbreak of confirmed C. perfringens occurred in Chicago. Multiple employees of a business became ill. Eight people became ill and two stool samples submitted showed greater than 106 organisms per gram. Illness began seven to 16 hours after consumption of burritos from a newly opened establishment in March 2006. The food was prepared at a restaurant in Wheeling, Illinois and was sold at the Chicago location. Investigation by the Cook County Food Protection Division (FPD) found critical violations including operating without a license and improper temperature for food storage. A citation was issued for closure of the establishment.

66 • C. perfringens caused four foodborne outbreaks in 2002, three in 2003, one in 2004, and two in 2006 and there were none in 2005.

Confirmed Outbreaks 1 Total number of ills 8 Average number of ills/outbreak 8 Number of cases hospitalized 0 Number of fatalities 0 Outbreak months March 1 Counties of outbreaks Cook 1 Food testing Yes, burritos positive

Shiga toxin producing E. coli (E. coli O157:H7 and others) Foodborne outbreaks of E. coli O157:H7 have been linked to undercooked ground beef, apple cider, sprouts and lettuce. Other types of E. coli also can be pathogenic in humans and cause outbreaks. A total of 4,432 E. coli O157:H7 cases reported to CDC in 2006. Ground beef is the most common vehicle in foodborne outbreaks. Produce-associated outbreaks are also common. Person-to-person outbreaks occur most commonly in day care centers.

Case definition Laboratory confirmation of an outbreak occurs when E. coli O157:H7 or other Shiga toxin-producing E. coli is isolated from stool of two or more ill persons or from the implicated food or water.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - Two confirmed E. coli O157:H7 outbreaks were reported. o The first outbreak occurred in Cook County in June where two cases of E. coli O157:H7 were reported by a hospital and both had a history of eating at the same restaurant in the past week. Human isolates matched by pulse field gel electrophoresis (PFGE) (pattern O609mlEX- 2c/EXHX01.0124). Both cases were seen and admitted to the same hospital. Hospital personnel reported the unusual occurrence of two cases at the same time. Environmental samples were taken from the restaurant; all were negative for the pathogen. No fatalities were reported. None of the restaurant employees reported diarrheal illness and all tested negative for bacterial pathogens. o The second outbreak occurred in August and was a multi-state outbreak. Two of the four persons tested in Illinois matched the outbreak’s PFGE pattern. Fresh spinach was the food item identified to be the likely source of the outbreak and spinach samples collected in other states matched the

67 PFGE pattern for the outbreak. Spinach eaten by ill persons was tested and positive for the pathogen. Two people were hospitalized and no fatalities occurred. Cases were also reported from other states. • There were two STEC outbreaks in each of the following years: 2002, 2003, 2004 and 2006 each; one outbreak was reported in 2005.

Confirmed Outbreaks 2 Total number of ills 6 Average number of ills/outbreak 3 Number of cases hospitalized 2 Number of fatalities 0 Outbreak months June 1 August 1 Counties of outbreaks Cook 1 multiple counties 1 Food tested 1: spinach positive Food handlers tested 1: negative Environmental specimen tested none

Enterotoxigenic E. coli Enterotoxigenic E. coli is the most common cause of traveler’s diarrhea. People are the reservoir for this organism. Transmission is usually from consumption of food or water contaminated with feces from infected persons. The incubation period is 10 to 12 hours if one toxin is present and 24 to 72 hours if both toxins are present. Symptoms are acute watery diarrhea. Three outbreaks were reported in Illinois from 1998 to 2006.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - None.

Salmonella Salmonella is the most common causative agent associated with bacterial foodborne outbreaks. The incubation period for Salmonella is six to 72 hours. Symptoms may include diarrhea, vomiting, fever and headache. One of the multi-state outbreaks in 2006 included S. ser. Tennessee associated with peanut butter. A case-control study linked illness to peanut butter consumption, and S. ser. Tennessee was found in peanut butter. S. ser. Tennessee is more likely to cause urinary tract infections than other serotypes. Another outbreak involved cases linked to fruit salad served in health care institutions in the northestern United States and Canada. The source of contamination was not identified at the processing plant.

68 Case definition A laboratory-confirmed outbreak of Salmonella occurs when bacteria are either cultured from implicated food or Salmonella of the same serotype is cultured from clinical specimens from two or more ill individuals.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - Four confirmed outbreaks were reported with 41 people ill (mean = 10 persons ill per outbreak). Outbreaks occurred in Cook (city of Chicago), Henry, and Macon Counties. One multi-state outbreak had cases who were residents of multiple counties in Illinois. The serotypes involved in the outbreaks were Enteritidis, Newport, Berta, and Tennessee. Food handlers were tested in three of the outbreaks and in two outbreaks food handlers tested positive for Salmonella. Contributing factors were unknown for three of the four outbreaks except for one where an ill food handler was a contributory factor. Food testing was performed in two outbreaks and in one outbreak Salmonella was identified in peanut butter. o The first Salmonella outbreak of 2006 occurred in late May in Macon County. Eleven individuals reported being ill after eating in one restaurant on various dates. Twenty-four possible cases gave specimens for testing and 11 tested positive for S. ser. Enteritidis. The restaurant voluntarily closed and environmental samples were taken, all of which were negative for the pathogen. Five of the 18 employees, including the cook, tested positive for S. ser. Enteritidis. Food handling employees were restricted from work until release specimens were negative and the restaurant was able to re-open after a week. There were three people hospitalized and no fatalities. o In August, nine individuals reported having symptoms of diarrhea, fever, and abdominal cramps after eating at a restaurant in Henry County. Incubation period averaged 60 hours. Seven of the nine human specimens submitted were positive for S. ser. Newport. Six food handlers were tested and one was positive for the pathogen. There were three individuals hospitalized and no fatalities. o One Salmonella outbreak occurred in October. In this outbreak, the Chicago Department of Public Health alerted IDPH to an increased number of S. ser. Berta diagnoses in one month, which is unusual given that two to seven is the average annual count for this diagnosis in Chicago. Five individuals were found to have the same PFGE pattern and all reported eating carnitas from the same grocery store. Food samples from the store, taken one month after the onset of illness, yielded negative results and eight employee samples were also negative. o The last Salmonella outbreak started in August of 2006 with the last case becoming ill on March of 2007. This outbreak was part of a nationwide outbreak of S. ser. Tennessee found in Peter Pan and Great Value peanut butter brands. There were a total of 16 people who were reported ill. Cases were from multiple counties. Three peanut butter samples in Illinois were found positive for the Salmonella strain, two of which were submitted by

69 cases. Alerts were issued both nationally and statewide on the recall of peanut butter brands Peter Pan and Great Value with numbers 2111 on their containers indicating the same manufacturing facility. • In 2002, there were six Salmonella outbreaks, five in 2003, seven in 2004, six in 2005 and four in 2006.

Confirmed Outbreaks 4 Total number of ills 41 Average number of ills/outbreak 10 Number of cases hospitalized 13 Number of fatalities 0 Outbreak months May 1 August 2 October 1 Counties of outbreaks Cook 1 Henry 1 Macon 1 Multi-county 1 Food testing positive 1 Environmental specimen tested unknown Contributing factor identified.

Suggested Readings Landry, L., et al. Salmonella oranienburg infections associated with fruit salad served in health care facilities – Northeastern United States and Canada, 2006. MMWR 2007; 56(39):1025-8.

Shigella The Shigella organism is not a common cause of foodborne outbreaks. Instead, it causes a gastrointestinal illness often transmitted from person-to-person. However, outbreaks have been associated with consumption of bean dip, lettuce, parsley and contaminated water. Outbreaks of shigellosis have also been associated with swimming in contaminated water.

Case definition The case definition for an outbreak of Shigella is identification of the same serotype of the bacteria in two or more ill persons.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - None.

70 Staphylococcal food poisoning One type of foodborne illness, classified as intoxication, is caused by enterotoxin- producing strains of S. aureus. Within 30 minutes to eight hours (usually two to four hours) after eating contaminated food, a person may experience explosive vomiting and diarrhea. The duration of illness is usually short - less than 24 hours. Humans are considered to be the primary source of the organism in foodborne outbreaks. S. aureus can be found in nasal passages, throat and hair and on the skin of healthy people; bacteria are present in high numbers in cuts, pustules and abscesses. The enterotoxins produced by S. aureus are heat stable. The organism may produce toxin in foods and then die so cultures of foods may be negative and yet the foods contained the staphylococcal enterotoxin that made people ill. Foodborne outbreaks caused by S. aureus and those caused by the B. cereus type where vomiting predominates have similar incubation periods and clinical syndromes.

Case definition Laboratory confirmation of an outbreak attributable to S. aureus requires detection of enterotoxin in food or organisms with the same phage type in stools or vomitus of two or more cases or isolation of greater than 105 organisms per gram in properly handled food.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 – One suspected outbreak and one confirmed outbreak were reported. The one suspected outbreak in February was either S. aureus or B. cereus but the agent was not confirmed. o In September, 23 people became ill after eating carnitas from a Chicago restaurant, 13 were considered probable cases due to lack of laboratory confirmation but consistent symptoms. The median incubation period was 1.75 hours and median illness duration was one day. Left-over foods were tested and were found to have large quantities of colony forming units per gram of S. aureus. Stool cultured from individuals yielded negative results. Improper food storage and temperature were found on second inspection of the facility. Three people were hospitalized and there were no fatalities. • Outbreaks: 2002 (one), 2003 (six), 2004 (two), 2005 (none) and 2006 (two). Confirmed Outbreaks 1 Total number of ills 23 Average number of ills/outbreak 23 Number of cases hospitalized 3 Number of fatalities 0 Outbreak months September 1 Counties of outbreaks Cook 1 Environmental specimen tested None Food Testing positive 1, pork carnitas

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Chemical agents This category includes toxins such as ciguatera and scombrotoxin, associated with fish consumption. Ciguatera toxin poisoning is caused by the ingestion of the toxin in predatory reef fish, such as barracuda, amberjack and grouper. The toxin is initially produced by dinoflagellates that are eaten by herbivorous fish, which are then consumed by the predatory fish. There is a test to detect the toxin in fish. However, the toxic fish have a normal taste and appearance. The toxin cannot be destroyed by cooking or freezing. Symptoms of diarrhea and vomiting develop within three to six hours after consuming contaminated fish. Neurologic symptoms may follow and persist for weeks or months. These neurologic symptoms include numbness, tingling of the mouth and extremities, muscle pain and weakness, and reversal of temperature sensation. There is no diagnostic test or treatment available for humans. Scombroid fish poisoning occurs after persons have consumed fish that contain high levels of histamine or other biogenic amines. Histamines accumulate when bacterial enzymes metabolize histidine in fish. Histamines are not destroyed when fish are frozen or cooked. This occurs when fish is held at high temperatures. Symptoms include facial flushing, sweating, rash, a burning or peppery taste in the mouth and diarrhea. More severe symptoms can occur and result in the need for medical treatment. Prevention is consistent temperature control of fish at less than 41 F at all times. Rapid cooling of fish after catch is the best method for prevention of scombroid fish poisoning. Scombridae include tuna and mackerel which have high levels of free histidine and are the main fish type linked to scombroid poisoning. Other fish implicated include mahi mahi, amberjack, bluefish, abalone and sardines. From 1998 to 2002, 118 scombroid fish poisoning outbreaks were reported to CDC.

Case definition The case definition for ciguatera toxin outbreaks is the demonstration of ciguatoxin in epidemiologically implicated fish or a clinical syndrome among persons who have eaten a type of fish previously associated with ciguatera fish poisoning. The case definition for scombroid toxin outbreaks is demonstration of histamine in epidemiologically implicated fish or a clinical syndrome among persons who have eaten a type of fish previously associated with histamine fish poisoning.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 - One suspect outbreak was reported. o In January, several Peoria area high schools reported student complaints of vomiting and abdominal cramps. There were a total of 27 ill students found who ate tortilla shells from different high school cafeterias. These tortilla shells were supplied by the same manufacturer to the schools. They were tested and no viral or bacterial pathogens found, but tortilla shells were found to have very high levels of calcium propionate, a preservative. The manufacturer voluntarily recalled the tortilla shells.

72 Chemical Confirmed Suspected* Outbreaks 0 1 Total number of ills 0 27 Average number of ills/outbreak 0 27 Number of cases hospitalized 0 0 Number of fatalities 0 0 Outbreak months January 0 1 Counties of outbreaks Peoria 0 1 Environmental specimen tested --- none Food Tested Excess calcium in tortillas from a manufacturer

Suggested readings Davis, J. et al. Sombroid fish poisoning associated with tuna steaks – Louisiana and Tennessee, 2006. MMWR 2007;56(32):817-819.

Parasitic agents There are a variety of parasitic agents that can cause foodborne or waterborne outbreaks, for example, Cryptosporidia, Cyclospora and Giardia. The incubation periods for parasitic agents can be up to 25 days.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 – 2 suspected. o One outbreak occurred in July in Kane County where attendees of a catered birthday party reported having diarrhea and abdominal cramps approximately one week after the event. There were a total of 91 exposed individuals with 44 out of the 77 interviewed reporting illnesses which lasted for one to 24 days. Despite testing, no human specimen was found positive for bacterial pathogens or for Cyclospora. Based on the incubation period, symptoms, and duration of illness, this outbreak was suspected to be Cyclospora with the absence of confirmatory laboratory diagnosis. o In August, an employee of a business in Kane County called to report that she became ill with diarrhea and had tested positive for C. difficile and that approximately 18 of her co-workers have been ill with diarrhea and abdominal cramps. Upon interview, it was found that an employee event happened in June and was catered by the same caterer as the other parasitic outbreak. Eight individuals sought medical evaluation but no pathogen was isolated. Cases were not tested for Cyclospora. Because of the incubation period, symptoms, and duration of illness, this was suspected to be due to a parasitic cause.

73 Parasitic Confirmed Suspected* Outbreaks 0 2 Total number of ills 0 62 Average number of ills/outbreak 0 31 Number of cases hospitalized 0 0 Number of fatalities 0 0 Outbreak months July 0 2 Counties of outbreaks Kane 0 2 Food handler positive for pathogen 0 Environmental specimen tested None None Food tested None

Viral gastroenteritis Noroviruses are a common cause of gastroenteritis in the United States. Estimates are that 23 million people are affected by noroviruses in the United States each year. There are five genogroups (1-5). Genogroup G1 (Norwalk virus, Southampton virus and Desert shield virus), G2 (Toronota virus, Mexico virus, Hawaii virus, Bristol virus, Lordsdale virus, camberwall virus, Snow Mountain agent and Melksham virus) and genogroup G4 infect humans, genogroup G3 has been found in cattle and genogroup G5 has been identified in mice. Sapoviruses have only been identified in humans, especially children. Noroviruses are transmitted through consumption of contaminated food or water, directly from person-to-person and from airborne droplets produced during vomiting. The most common method of spread is via the fecal-oral route. The virus is excreted in stool and vomitus for up to 10 days. The incubation period and duration of illness ranges from 24 to 48 hours. Duration of illness ranges from 12 to 60 hours. Virus shedding peaks 25 to 72 hours after exposure to the virus. Within 48 to 72 hours after symptom onset, virus concentration in the stool declines below levels detectable by electron microscopy. An experimental study in Texas found that virus could be found in stool for a median of 28 days after using RT-PCR testing. Short-term immunity occurs after infection. Vomiting, diarrhea, headache and body aches are commonly reported. A common feature of norovirus outbreaks is secondary transmission to household members not exposed to the implicated food or water. Humans are the only known reservoir for these viruses. These viruses cannot replicate outside the human body and therefore will not multiply in food items. Characteristics of the virus that facilitate spread include low infectious dose, high concentration of virus in stool, strain diversity, environmental stability and prolonged shedding. Failure of an ill food handler to perform proper handwashing may result in fecal contamination of food. Illness caused by norovirus can be suspected based on incubation period, duration of illness, symptoms or by identification of the organism in stool. Noroviruses can survive freezing and temperatures of up to 60 C and can survive

74 chlorine levels up to 10 ppm (that exceeds what is normally present in public water systems). In an evaluation of norovirus outbreaks where specimens were submitted to CDC from July 2000 and July 2004, long-term care facilities, retirement centers and hospitals were the most likely sites of outbreaks. Person-to-person transmission was most common followed by foodborne transmission. Genogroup 2 was most common (79 percent) followed by genogroup 1 (19 percent) and sapovirus (2 percent). Serogroup 2 is the prevalent genogroup for noroviruses in outbreaks worldwide. Outbreaks are not uncommon in closed settings, such as detention facilities, cruise ships, long-term care facilities and hospitals. An outbreak of norovirus affected six consecutive cruises on a single ship. Multiple strains of norovirus were identified. The virus cannot be grown in ; a polymerase chain reaction (PCR) test is used to diagnose norovirus. Testing for viral gastroenteritis in humans is not useful for screening individual samples but is useful when multiple samples are available in an outbreak. Approximately 25 state health department laboratories, including Illinois, can do the RT-PCR to detect norovirus. Norovirus can be present in stools for up to a week after illness onset. Immunity is short-lived and appears to be strain specific. Since there are so many strains, individuals can be repeatedly infected by noroviruses during their lifetime. A study of experimental infection found that norovirus was excreted a median of 28 days after inoculation using RT-PCR testing.

Case definition Several laboratory tests may help to confirm an outbreak related to norovirus. These include positive results on RT-PCR, visualization of small round structured virus (SRSV) in electron microscopy of stool from ill individuals, or a fourfold rise in antibody titer to norovirus seen in acute and convalescent sera in most serum pairs. Multiple samples are needed from each outbreak to provide sufficient specimens to verify the causative agent as norovirus. An outbreak is considered confirmed when at least two ill persons have positive laboratory results.

Descriptive epidemiology Number of outbreaks reported in Illinois in 2006 – 28 suspected foodborne outbreaks of viral gastroenteritis, based on clinical syndrome, incubation period and duration of illness and 13 laboratory confirmed outbreaks were reported. Norovirus outbreaks affected 938 people who experienced compatible illness (median = 12 ill persons per outbreak). The average number of ills per outbreak was 23 with a range of three to 418 ill persons. The median incubation period for the confirmed outbreaks was 33 hours. The 41 norovirus outbreaks occurred in the counties of Cook, (21), DuPage (3), Vermilion (3), Livingston (2), Peoria (2), Pike (2), Winnebago (2), and one each for Jo Daviess, Kane, Lake, Marshall, Stephenson, and Will. Genotyping information was available on 18 outbreaks. Three were G1 (two confirmed and one suspect), 14 were G2 (nine confirmed and five suspect) and one outbreak involved both G1 and G2. Eighty-three of the cases sought health care consultation, 10 were hospitalized, and there were no fatalities. Food handlers were tested for norovirus in four outbreaks and

75 positive food handlers were identified in all four outbreaks. In five of the outbreaks, food handlers reported illnesses. In seven of the outbreaks, specific food vehicles were implicated. < The first confirmed outbreak occurred in the city of Chicago in January. A hotel administrator informed the Chicago Department of Health of multiple gastrointestinal illnesses among attendees of a dinner event in the hotel in addition to 10 ill employees. Sanitary inspection of the hotel kitchen found improper temperature and hygienic practices. A total of 418 individuals met the case definition, 375 primary cases among guests, 35 among employees, and eight secondary cases. Laboratory testing for norovirus was positive for 14 case specimens and three food handler specimens. Twelve cases were identified with norovirus G2 at the IDPH laboratory. Two were tested at outside laboratories and were not typed.Two people were hospitalized and there were no fatalities. < Another confirmed outbreak occurred in February after the DuPage County Health Department received a complaint that several persons attending a retirement party had similar gastrointestinal symptoms as well as several people from another group attending a rehearsal dinner in the same hotel. A total of 28 persons reported illness. Primary symptoms include vomiting and diarrhea. Eight samples from the retirement party attendees and six from food handlers were tested; two were positive among patrons and two among food handlers. Four persons were identified with norovirus G2. Three food items were epidemiologically linked to illness: smoked mozzarella, tossed salad and ice water. The latter two items were in common between both groups. One laboratory confirmed food handler served during the rehearsal dinner and the other laboratory confirmed food handler helped prepare the salad. There was also some co-mingling of the two parties since they had activities in close proximity. < A norovirus-confirmed outbreak occurred in March among attendees of a party where food was catered in Will County. Seventeen of the 22 attendees reported gastrointestinal illnesses such as vomiting and diarrhea. Three stool specimens were obtained and all were positive for norovirus G2. Further investigation revealed that one party attendee was already ill with symptoms of diarrhea. None were hospitalized and there were no fatalities. < Another outbreak in March happened in a restaurant in Jo Daviess County where 13 of 17 individuals became ill after eating in a restaurant. Symptoms included vomiting, diarrhea, abdominal cramps, prostration, fatigue, and body aches with a median incubation period of 29 hours and illness duration of 50 hours. One patron tested positive for norovirus G2. A food handler was also found to be positive for the norovirus G2. The ill food handler, who tested positive, prepared the vegetables and salad. There was one person hospitalized but there were no fatalities. Salad was

76 linked to the illness. < In April, three laboratory confirmed cases were found from an outbreak involving several groups of people who ate at a restaurant in Peoria County. There were a total of 18 patrons and 15 were interviewed. Eleven of them became ill with abdominal cramps, body aches, diarrhea, headaches and vomiting. The median incubation period was 39 hours with a range of 4 to 63 hours. Illnesses lasted from 4 to 50 hours, with a median of 12 hours. There was no preparation errors found upon inspection of the restaurant facility. Norovirus G2 was confirmed in this outbreak. < Another outbreak in April involved a family that gathered in a restaurant for an Easter meal in Cook County. Eight attendees developed symptoms of vomiting and diarrhea within a median incubation period of 36 hours. The duration of illness ranged from 6 to 24 hours with a median of 9 hours. Two specimens were tested for norovirus and both were found positive for norovirus G2. It is unknown if food handlers reported illness. < In May, a catered baptism celebration reported illnesses occurring in 16 individuals of the approximately 40 attendees. Symptoms include vomiting and diarrhea with an incubation period that ranged from 7 to 65 hours (median of 29.5 hours) and lasted for 12 to 48 hours (median of 42 hours). Four stool samples all tested positive for norovirus genotype 2. There were neither hospitalizations nor fatalities. No food handlers reported illness. < Another outbreak in May happened in Winnebago County. A graduation party in a private home was attended by 50 to 60 people including a 2- year old who had been ill with diarrhea and vomiting prior to the party. Fourteen guests became ill with the same symptoms. Two specimens were submitted and were both found to be positive for norovirus genotype 2. < Another May outbreak was reported in Vermilion County. Four of five individuals reported symptoms of diarrhea, vomiting and abdominal cramps after eating in a restaurant. Two specimens were found positive for norovirus genotype 2. The incubation period ranged from 25 to 33 hours (median of 29 hours) and illnesses lasted for 12 to 24 hours (median of 18 hours). The restaurant owner and a food handler reported becoming ill several days before the meal but were not tested. < Another outbreak occurred in October in Stephenson County among several groups of people, including persons attending a wedding rehearsal, a teacher’s lunch, and in persons who purchased carry out food from a restaurant. Twenty-three persons were ill with symptoms of vomiting, diarrhea and abdominal cramps. The incubation period ranged from 14 to 48 hours with a median of 30 hours and the duration of illness ranged from 28 to 120 hours with a median of 78 hours. Two specimens were tested and were positive for norovirus G2. Twenty-three persons

77 were reported to have been ill. Food handler illness status was unknown. < In Livingston County in the month of November, another norovirus outbreak occurred among 22 individuals who became ill after eating at a restaurant. Seven specimens were submitted and all of them tested positive for norovirus. Salad was implicated as the source of illness. One case was found to have both norovirus G1 and G2. The rest were G1. At least one food handler tested positive and food handlers reported illnesses. < Two norovirus outbreaks occurred in December. One outbreak occurred in Pike County in a group who met and ate buffet food in a restaurant. Several of the people became ill with symptoms of vomiting, diarrhea and abdominal cramps. Three ill persons submitted stool specimens and all were positive for norovirus G1. There were a total of 16 persons ill among the 24 attendees. The average incubation period was 37 hours and the average duration of illness was 21 hours. No ill persons were hospitalized. Contributory factors, including food handler illness, were unknown. < Another December norovirus outbreak occurred in the city of Chicago in approximately 72 members and guests of a social club who met in a restaurant and 46 reported becoming ill with diarrhea and/or vomiting. One case was hospitalized and there were no fatalities. Three of five specimens submitted were positive for norovirus G2. There were also two attendees who reported being ill during the event, but whether they contributed to transmission cannot be established. It is unknown if food handlers reported illness.

Suggested readings Atmar, R.L., et. al., Norwalk virus shedding after experimental human infection. Emerg Inf Dis 2008; 14(10): 1553-7. Glasscock, S., et al. Multistate outbreak of norovirus gastroenteritis among attendees at a family reunion-Grant County, West Virginia, October 2006.

78

Norovirus Confirmed Suspected* Outbreaks 13 28 Total number of ills 638 300 Average number of ills/outbreak 49 11 Number of cases hospitalized 4 6 Number of fatalities 0 0 Outbreak months January 1 2 February 1 2 March 2 5 April 2 5 May 3 2 June 0 1 July 0 1 August 0 2 October 1 0 November 1 4 December 2 4 Counties of outbreaks Cook 3 18 DuPage 2 1 Jo Daviess 1 0 Kane 0 1 Lake 0 1 Livingston 1 1 Marshall 0 1 Peoria 1 1 Pike 1 1 Stephenson 1 0 Vermillion 1 2 Will 1 0 Winnebago 1 1 Food handler positive for pathogen 4 0 Environmental specimen tested unknown 1

Hepatitis A Foodborne outbreaks of hepatitis A are uncommon. When they do occur they are often associated with foods contaminated by infected food handlers. Also, contaminated produce, such as lettuce or strawberries, may also be a source of illness. The incubation for hepatitis A is 28 to 30 days. The agent can be found in feces before the onset of illness.

Descriptive epidemiology Number of hepatitis A outbreaks in 2006 – None.

79

Recreational Water Outbreaks

Background In 2005 and 2006, Illinois was one of six states reporting at least four waterborne outbreaks to CDC. Of outbreaks reported to CDC in these two years, 69 percent were caused by parasites, such as Cryptosporidium. Outbreaks of Cryptosporidium in treated waters occurs because Cryptosporidium requires extended contact time with chlorine for inactivation and oocysts can survive for several days in typical swimming pools (1-3 ppm free chlorine). Important prevention messages are to not swim with diarrhea and to not swallow water while swimming. Chemicals are important to prevent microbial and algal growth in pools. However, these chemicals can cause illness if applied in the wrong proportions.

Descriptive epidemiology Number of recreational waterborne outbreaks in 2006 – Five outbreaks were reported. The outbreaks occurred in Lake, Logan, Tazewell, and two in Winnebago County. A total of 135 persons became ill due to recreational water exposure. Three of the outbreaks were determined to be caused by Cryptosporidium, one Legionella, and one was caused by an unknown etiology. There was a total of one person hospitalized and no fatalities for waterborne outbreaks in Illinois in 2006. • The first waterborne outbreak occurred in January in Logan County. Forty-three persons became ill with legionellosis after they used the hotel pool and spa facilities. Improper disinfection of the whirlpool and spa was determined to be the contributing factor to the outbreak. • In Winnebago County during the month of June, nine of 12 swimmers in two swimming classes at a village swimming pool reported burning on different parts of the body. The teachers of the two classes also reported burning rashes. The pathogen for this outbreak was unknown but it was determined that the water was acidic and that chlorine levels were not correct. • Another waterborne outbreak happened in Tazewell in July where 65 of approximately 105 exposed persons became ill after swimming in the pool and water park in the area. Eight specimens were submitted from ill persons and seven were positive for . Water testing on August 11 (illness onsets began on July 29) showed C. parvum from Pool B by PCR at CDC and Pool A was negative. • Two waterborne outbreaks happened in August. The site of exposure in both outbreaks were water parks in the counties of Lake and Winnebago. Eighteen individuals in Lake and four individuals in Winnebago became ill after being exposed to the recreational water facilities. In Lake County, two stool specimens both tested positive for Cryptosporidium, while three of the five stool specimens tested in Winnebago County tested positive for Cryptosporidium. No water testing was done in Winnebago County. Water tested negative in Lake County on August 19 and onsets of illness were August 7.

80

Suggested readings Yoder, J.S., et. al., Surveillance for waterborne disease and outbreaks associated with recreational water use and other aquatic facility-associated health events United States, 2005-2006 and Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking – United States, 2005-2006. MMWR 2008;57(SS-9).

81 Foodborne and waterborne outbreaks in Illinois in 2006.

Exposure IDPH Log Onset Incubation Place of Number Date City County ExpIl/lExp Symptoms* Hours Food Implicated Agent Implicated Status Preparation Place Eaten Legionnaires disease and Hotel/Motel; IL2006-34 01/01 Lincoln Logan 43/900 - Legionella Confirmed Pool/Spa Hotel

IL2005-80 01/01 Chicago Cook 4/5 D,V 7 Unknown Unknown Unknown Restaurant Restaurant 18/ Whole milk, Campylobacter IL2006-1 01/03 Coles unknown D,F,AC 72 unpasteurized jejuni Confirmed Farm Private home Nachos, IL2006-2 01/15 Forest Park Cook 5/10 D,V, 37 unspecified;dips Norovirus Suspect Restaurant Restaurant

IL2006-5 01/18 Flanagan Livingston 15/17 D,V 28-52 Unknown Norovirus Suspect Restaurant Restaurant Commercial 27/ Tortilla, product at IL2006-3 01/18 Peoria Peoria unknown AC,V <1 unspecified Excess calcium Suspect School School 418/ D,F,V, AC, Restaurant at Restaurant at IL2006-6 01/30 Chicago Cook unknown BA 32 Unknown Norovirus G2 Confirmed hotel hotel 4/ Banquet Banquet IL2006-8 02/10 Arlington Heights Cook unknown D,V,AC 31 Unknown Norovirus Suspect facility facility B. cereus/ S. IL2006-7 02/10 North Riverside Cook 7/7 AC,V 0.75 Unknown aureus Suspect Restaurant Restaurant

IL2006-9 02/12 Danville Vermilion 7/7 AC,D 32 Unknown Norovirus G2 Suspect Restaurant Private home Tap water;green banquet salad; Banquet Bacility at IL2006-17 02/24 Carol Stream DuPage 28/56 D,V 32 mozzarella Norovirus G2 Confirmed facility at hotel hotel Sandwich, vegetable- IL2006-22 03/04 Morton Grove Cook 16/30 AC,D,V 31 based Norovirus Suspect Caterer Hospital

IL2006-25 03/12 Lockport Will 17/22 AC,D,V 36 Unknown Norovirus G2 Confirmed Caterer Private Home

IL2006-27 03/16 Wilmette Cook 3/3 AC,F,V 38 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-38 03/26 Chicago Cook 3/3 D,V 30 Unknown Norovirus Suspect Restaurant Restaurant vegetable- IL2006-35 03/26 Galena Jo Daviess 13/17 AC,D,V 29 based salads Norovirus G2 Confirmed Restaurant Restaurant

IL2006-43 03/27 Orland Park Cook 4/15 AC,D,V 31 Unknown Norovirus Suspect Restaurant Restaurant 8/ Clostridium IL2006-33 03/27 Chicago Cook unknown D 12 burrito, beef perfringens Confirmed Restaurant workplace Exposure IDPH Log Onset Incubation Place of Number Date City County ExpIl/lExp Symptoms* Hours Food Implicated Agent Implicated Status Preparation Place Eaten

IL2006-39 03/29 Chicago Ridge Cook 6/11 D,V 13 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-40 04/01 Dunlap Peoria 11/15 D,V 39 Unknown Norovirus Confirmed Restaurant Restaurant 82 Caterer, Church, IL2006-42 04/02 Peoria Peoria 39/57 D,V,AC 32 Unknown Norovirus Suspect Private home Church

IL2006-45 04/03 Orland Park Cook 5/8 D,V 27 Unknown Norovirus Suspect Restaurant Restaurant Grocery store, Private home, IL2006-47 04/09 Naperville DuPage 20/36 D,V, AC 31 Unknown Norovirus Suspect Restaurant Private home

IL2006-50 04/16 Orland Park Cook 8/12 AC,D,V 36 Unknown Norovirus G2 Confirmed Restaurant Restaurant

IL2006-61 04/22 Sugar Grove Kane 23/35 D,V 32 Ice Norovirus Suspect Restaurant Rental Hall

IL2006-65 04/24 Tinley Park Cook 14/20 D,V 30 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-66 05/01 Aurora DuPage 18/24 AC,D,V 29 Unknown Norovirus G2 Confirmed Restaurant Private home

IL2006-71 05/05 Wheeling Cook 5/5 D,V,AC 34 Unknown Norovirus Suspect Restaurant Office 5/ IL2006-106 05/10 Schaumburg Cook Unknown D,V 34 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-74 05/14 Roscoe Winnebago 14/55 D,V U Unknown Norovirus G2 Confirmed Private home Private home 11/Unkno IL2006-82 05/26 Decatur Macon wn D,AC, F, V 36 Unknown S. ser. Enteritidis Confirmed Restaurant Restaurant

IL2006-77 05/31 Danville Vermilion 4/5 AC,D,V 29 Unknown Norovirus G1 Confirmed Restaurant Restaurant Food at lake Food at lake IL2006-81 06/11 Carlyle Clinton 25/67 AC,D,V 33 Unknown Unknown Unknown harbor harbor Food at lake Food at lake IL2006-83 06/15 Carlyle Clinton 19/45 AC,D,V U Unknown Unknown Unknown harbor harbor Im- IL2006-87 06/16 Pecatonica Winnebago 9/12 burning rash mediate - Unknown Unknown Pool Pool

IL2006-86 06/18 Arlington Heights Cook 6/10 D,V 30 Unknown Norovirus Suspect Restaurant Private home

2/ Workplace, IL2006-88 06/25 Chicago Cook unknown D 120 Unknown E. coli O157:H7 Confirmed Restaurant not cafeteria Exposure IDPH Log Onset Incubation Place of Number Date City County ExpIl/lExp Symptoms* Hours Food Implicated Agent Implicated Status Preparation Place Eaten

IL2006-98 07/03 Batavia Kane 18/24 D,AC 144 Unknown Parasitic Suspect Caterer Workplace Banquet Restaurant, facility, banquet IL2006-89 07/08 Glenview Cook 12/26 AC,D,V 43 Unknown Norovirus Suspect Restaurant facility

83 potato salad; pork, beans, IL2006-97 07/09 Batavia Kane 44/77 D 168 baked Parasitic Suspect Caterer Club house B. cereus/ C. IL2006-91 07/16 Glenview Cook 3/5 D 14 Unknown perfringens Suspect Restaurant Restaurant 2/ IL2006-111 07/27 Dolton Cook unknown D,V 6 Unknown Unknown Unknown Restaurant Private home Pool with Pool with IL2006-101 07/29 Pekin Tazewell 65/105 D,AC Unknown - Cryptosporidium Confirmed water park water park

Private home, IL2006-96 07/30 Chicago Cook 10/30 D,V 12 Unknown Unknown Unknown caterer Private home Commercial 16/ S. ser. product, IL2007-39 08/01 Multi-County Unknown D U Peanut Butter Tennessee Confirmed Private home Private homes 9/ IL2006-100 08/01 Geneseo Henry Unknown D 60 Unknown S. ser. Newport Confirmed Restaurant Restaurant

Restaurant & IL2006-105 08/06 Peoria Peoria 39/52 D,V,AC 30 Sandwich, club Unknown Unknown Restaurant work IL2006-103 08/07 Chicago Cook 3/3 AC,D,V 43 Unknown Norovirus Suspect Restaurant Restaurant 2/ sandwich, IL2006-112 08/14 Evanston Cook Unknown AC,D 12 turkey unknown Unknown Restaurant Work 4/ IL2006-117 08/18 Rockford Winnebago Unknown D 120 - Cryptosporidium Confirmed Water park Water park 18/ IL2006-109 08/18 Gurnee Lake Unknown D 144 - Cryptosporidium Confirmed Water park Water park 5/ IL2006-113 08/23 Vermilion Unknown D,V 36 Unknown Norovirus Suspect Restaurant Restaurant 4/ spinach, IL2006-118 08/31 multiple Multi-County unknown D, HUS (1) 36 unspecified E. coli O157:H7 Confirmed Grocery store Private home IL2006-121 09/16 Naperville Will 52/69 D,AC 11 Chicken Biryani Unknown Unknown Caterer Private home 23/ IL2006-122 09/24 Chicago Cook Unknown AC,D,V 2 Pork carnitas S. aureus Confirmed Restaurant Restaurant Exposure IDPH Log Onset Incubation Place of Number Date City County ExpIl/lExp Symptoms* Hours Food Implicated Agent Implicated Status Preparation Place Eaten 13/ IL2006-124 09/26 Chicago Cook Unknown AC,D, V 9 Unknown Unknown Unknown Restaurant Restaurant 23/ IL2006-126 10/07 Freeport Stephenson Unknown D,V 30 Unknown Norovirus G2 Confirmed Restaurant Restaurant

IL2006-133 10/21 Chicago Cook 6/8 D,V 12 Unknown Unknown Unknown Restaurant Restaurant 6/ chicken, buffalo Restaurant or IL2006-134 10/25 Bloomington McLean Unknown D,V 12 wings unknown Unknown deli Private home 5/ IL2006-169 10/27 Chicago Cook Unknown AC,D,F,V 68 Pork carnitas S. ser. Berta Confirmed Grocery store Private home

84 IL2006-138 11/03 Gurnee Lake 8/10 D,V 20-28 Unknown Norovirus Suspect Caterer Work IL2006-141 11/12 Norridge Cook 7/13 D,V,HA 34 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-154 11/26 Lacon Marshall 12/41 D,V 33 Unknown Norovirus Suspect Restaurant Restaurant

IL2006-153 11/26 Milton Pike 14/32 AC,D,V 33 Unknonw Norovirus Suspect Caterer Church hall

IL2006-150 11/26 Fairbury Livingston 22/31 D,V 39 Green salad Norovirus Confirmed Restaurant Restaurant

IL2006-176 11/28 Worth Cook 7/8 D,V 8 Unknown Unknown Unknown Restaurant Restaurant

IL2006-211 12/01 Forest Park Cook 12/17 AC,D,V 39 Unknown Norovirus Suspect Restaurant Work

IL2006-172 12/05 Perry Pike 16/24 D,V 37 Unknown Norovirus G1 Confirmed Restaurant Restaurant

IL2006-175 12/08 Chicago Cook 46/72 AC,D,V 34 Unknown Norovirus G2 Confirmed Restaurant Restaurant IL2006-174 12/09 Chicago Cook 2/10 D,V 2 Unknown Unknown Unknown Restaurant Restaurant 18/ IL2006-186 12/11 Chicago Cook Unknown AC,D,V 41 Unknown Norovirus Suspect Restaurant Church 2/ IL2006-191 12/19 Northbrook Cook Unknown AC,D,V 13 Unknown Unknown Unknown Restaurant Restaurant Private home/Restaur IL2006-197 12/25 Durand Winnebago 7/9 D,V 33 Unknown Norovirus Suspect ant Private home Corned beef, IL2006-202 12/30 Forest Park Cook 22/31 AC,D,V 30 unspecified Norovirus Suspect Restaurant Restaurant * BA=body ache, BD=bloody diarrhea, D=diarrhea, F=fever, H=headache, V=vomiting, AC=cramps

85 Giardiasis

Background Giardia is the most commonly diagnosed intestinal parasite in public health laboratories. A common intestinal parasite of children, especially those attending day care, it is spread from person to person through fecal-oral transmission and has a median incubation period of seven to 10 days. Many infections are asymptomatic and repeated infections can occur in the same person. There are three species of giardia: G. lamblia, G. agilis and G. muris. The main human pathogen is G. lamblia. Cysts are infective immediately upon excretion and can remain viable for months. The infectious dose is low; as few as 10 cysts can cause infection and excretion can continue for months. Giardiasis also affects domestic and wild mammals including cats, dogs, cattle, deer and beavers. Persons at greatest risk are children in day care facilities, close contacts of these children, men who have sex with men, backpackers, persons in contact with infected animals, campers, and persons drinking from shallow wells contaminated by run-off with the organism. The most commonly identified intestinal parasite in international travelers is G. lamblia. Giardiasis peaks in late summer and early fall. Metronidazole is the most frequent treatment for giardiasis in the United States. Approximately 85 percent of infections can be diagnosed with a single stool specimen. Diagnosis is made by identification of the parasite in wet mount staining with trichrome or iron hematoxylin, by direct fluorescent antibody detection, or by enzyme immunosorbent assay. Because of its long period of communicability, low infectious dose and environmental resistance, giardiasis is easily transmitted. Preventive measures should include practicing good hygiene, avoiding water or food that might be contaminated and avoiding fecal exposure during sex with infected persons. In 2006, the CDC received reports on 18,953 Giardia cases.

Case definition The case definition for giardiasis in Illinois is the presence of diarrhea and the identification of Giardia trophozoites or cysts in stool, or detection of antigen by the ELISA antigen test. Carriers are those persons identified with Giardia trophozoites or cysts in the stool but who have no symptoms of disease.

Descriptive epidemiology • Number of cases (confirmed and probable) reported in Illinois in 2006 – 695 (five- year median = 861); the incidence rate was six per 100,000 population. All but one of the cases was confirmed. Reported cases decreased from 2005 (See Figure 41). • Age – The mean age of cases was 42 years. The age group with the highest Giardia incidence (18 per 100,000) was 1 to 4 years of age (Figure 42). • Gender – Fifty-eight percent were male. • Race/ethnicity – Sixty-eight percent were white, 13 percent were African American and 19 percent were other races; 16 percent were Hispanic.

88 • Seasonal variation - More cases occurred in August (Figure 43). • Geographic variation - The incidence rate by county ranged from 0 to 27 per 100,000 population by county (Figure 44). Counties with the highest average annual giardiasis incidence rates per 100,000 population over this period were Jo Daviess (27 per 100,000), McDonough (21), Scott (18), DeWitt (18) and Kendall (16). • Clinical - Symptoms were diarrhea (90 percent), vomiting (31 percent) and fever (20 percent). Thirteen percent were hospitalized. No fatalities were associated with cases. At least 63 persons were asymptomatic. • Reporters – Cases were most frequently reported by laboratory staff (64 percent) and infection control professionals (30 percent). • Employment – Cases reported working in the following sensitive occupations: day care center (one case), food service (two cases), health care worker (five cases), residential facility (one case) and other sensitive occupation (six cases). • Risk factors – o Contact with animals – Contact with animals was reported in 126 of 340 cases (37 percent). Dog contact (86 cases) and cat contact (47 cases) were most frequent. o Travel – Sixty cases (17 percent) reported travel to another country. The two countries most frequently visited were Mexico (11 cases) and India (eight cases). Fifty (fourteen percent) of cases traveled to another state. Wisconsin (10 cases) and Florida (six cases) were the most common states visited. o Swimming – Forty-six of 361 cases (13 percent) of cases reported swimming in non-chlorinated water, while 55 of 347 cases (16 percent) reported swimming in chlorinated water. o Well water exposure - Twenty-nine of 374 cases (8 percent) reported drinking well water. o Residential facility - Cases attended or resided in day care centers (11) and residential facilities (one). Forty-one of 367 cases (11 percent) reported contact with a day care. • Outbreaks – No foodborne outbreaks were reported in 2006.

Summary Giardiasis cases decreased in 2006 compared to the previous five-year median (861). The mean age of cases was 42 years but the highest incidence occurred in those 1 to 4 years of age. More cases occurred in the warmest months of the year.

89 Figure 41. Giardiasis Cases in Illinois, 2001-2006

1000 904 871 861 807 772 800 695 600 400 200

Number Number of cases 0 2001 2002 2003 2004 2005 2006 Year

Figure 42. Incidence by Age of Giardiasis Cases in Illinois, 2006

20 15 10 5 0

Incidence per 100,000 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age in years

Figure 43. Giardiasis Cases in Illinois by Month, 2006

150

100

50

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of onset

90 Figure 44. Map of Giardia Incidence by County in Illinois, 2006

91

Hemolytic Uremic Syndrome (HUS)

Hemolytic uremic syndrome (HUS) is characterized by acute hemolytic anemia, thrombocytopenia and renal insufficiency. Many microbes including Shigella dysenteriae, Salmonella ser. Typhi, Campylobacter jejuni and E. coli O157:H7 have been linked to HUS. Bacteria, such as E. coli O157:H7 produce a toxin that can cause vascular cell damage. The most serious sequelae from infection with Shiga toxin- producing E. coli in people is HUS.

Background HUS occurs primarily in children younger than 5 years of age after infection by an organism producing shiga toxin and causing diarrhea. HUS usually occurs within two to 14 days after onset of diarrhea. Almost half of children with HUS require dialysis. The illness can involve the central nervous system (CNS), pancreas, heart and other organs. During 2006, 288 cases of HUS were reported to CDC from 37 states. The majority of reported cases in 2006 were in patients younger than 5 years of age. Antibiotic therapy has been identified as a risk factor for HUS development; therefore, if antibiotic therapy is being considered, it should be withheld for treatment of patients with diarrhea until a culture confirms that E. coli O157:H7 is not present in a stool specimen.

Case definition Laboratory criteria are both acute anemia with microangiopathic changes (i.e. schistocytes, burr cells or helmet cells) on peripheral blood smear and acute renal injury evidenced by either hematuria, proteinuria, or elevated creatinine level (i.e. greater than or equal to 1.0 mg/dL in a child aged less than 13 years or greater than or equal to 1.5 mg/dL in a person aged greater than or equal to 13 years, or greater than or equal to 50 percent increase over baseline). A probable case is an acute illness diagnosed as HUS or TTP that meets the laboratory criteria in a patient who does not have a clear history of acute or bloody diarrhea in the preceding three weeks, or an acute illness diagnosed as HUS or TTP that a) has onset within three weeks after onset of an acute or bloody diarrhea and b) meets the laboratory criteria except that microangiopathic changes are not confirmed. A confirmed case is an acute illness diagnosed as HUS or TTP that both meets the laboratory criteria and began within three weeks after onset of an episode of acute or bloody diarrhea.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – Eight cases were reported to CDC. Cases reported from 2002 to 2006 are show in Figure 45. • Of the eight cases, three also were listed as an E. coli O157:H7 case. Three additional cases of physician diagnosed HUS were listed under E. coli O157. • Age - The eight HUS cases reported to CDC ranged from 1 year to 58 years of age.

92 Four cases were younger than six years of age. • Sex – Five cases were female and three were male. • Race/ethnicity – All cases were white; none were reported as Hispanic. • Seasonal - Onsets occurred from June to October. • Geographic location – Counties in which cases occurred were Kankakee (two cases), and one case each from Champaign, Cook, Fayette, Grundy, Kane and Lee counties. • Clinical – All cases had diarrhea, and six cases reported having bloody diarrhea. All cases were admitted to the hospital. Five cases needed dialysis. No cases were fatal.

Summary Eight cases of HUS were reported by Illinois to CDC in 2006, and an additional three cases were physician diagnosed. The three not reported were due to confirmed infection with E. coli O157:H7.

Figure 45. Hemolytic Uremic Syndrome Cases in Illinois, 2001- 2006

10 8 5 4 4 5 3

0 Number of cases of Number 2002 2003 2004 2005 2006 Year

93 Hepatitis A Background Hepatitis A virus is transmitted though the fecal-oral route by person-to-person contact and by contaminated food, water or fomites. HAV infection can spread in household members, through day care centers, among persons who consume contaminated or uncooked food handled by infected workers and among men who have sex with men (MSM). It is one of the most frequently reported vaccine preventable diseases. The hepatitis A rate in the United States for 2006 was 1.2 per 100,000. Rates declined 81 percent from 1990 to 2006. There is only one serotype, and immunity after infection is lifelong. Young children who are frequently asymptomatic when infected may play an important role in HAV transmission in communities. The incubation period is 15 to 50 days. Onset of illness with HAV can be abrupt with fever, anorexia, nausea and abdominal discomfort, followed by jaundice. The disease can vary from one to two weeks of mild symptoms to a severe illness lasting months. Severity generally increases with age, and many infections are asymptomatic, especially in young children. Peak levels of the virus appear in the feces one to two weeks before symptom onset and diminish rapidly after symptoms appear. Serologic testing for IgM anti-HAV is required for laboratory confirmation of hepatitis A infection. IgM anti-HAV becomes detectable five to 10 days after exposure and can persist for up to six months. Hepatitis A virus infection can be prevented by good personal hygiene, particularly handwashing, preexposure or postexposure immunization with immune globulin (IG), and preexposure immunization with HAV vaccine. The administration of IG for persons exposed to HAV is 85 percent effective in preventing symptomatic HAV infection if given within two weeks of exposure and may prevent infection entirely if given soon after exposure. The effect of IG starts within hours of administration and provides from three to six months of protection. Without prophylaxis the secondary attack rate ranges from 15 percent to 30 percent in households with an HAV case. Persons should be considered exposed if they are household contacts of a confirmed case or persons sharing illicit drugs with a confirmed case. Others with ongoing personal contact should be provided with prophylaxis. For PEP for non-immune persons who have been exposed to HAV through sexual or household contact, a single dose of or IG should be given. The second dose should be administered to complete the series. For persons 12 months to 40 years of age, vaccine is recommended within two weeks of exposure. For persons aged 41 and older IG is preferred. For contacts who are children younger than 12 months, immuncompromised persons, persons who have chronic liver disease and persons contraindicated for vaccine IG should be given. In child care centers, vaccine or IG should be given to all non-immune staff members and attendees where a case of hepatitis A is identified in children or employees or if cases are recognized in two or more households of center attendees. If children with diapers are not present, only classroom contacts of the hepatitis A case need prophylaxis. If cases occur in three or more households, prophylaxis should be considered for household members of center attendees. Other food handlers at the same establishment as a food handler with hepatitis A should receive prophylaxis. Patrons of a food facility may be recommended for PEP if during the time when the food handler was likely to be infectious, the food

94 handler both directly handled uncooked or cooked food and had diarrhea or poor hygiene, and patrons can be treated within two weeks. In 1995, a hepatitis A vaccine was licensed for individuals older than 2 years of age. The vaccine was recommended for individuals traveling to areas where there is a higher endemnicity rate. In 2006, ACIP recommended routine vaccination of all children aged 12 months or older. Recommendations are for vaccine use in children at 12-23 months. Catch-up vaccination of older children in selected areas and vaccination for high risk persons (travelers to endemic areas, men who have sex with men and illicit drug users). Travelers to developing countries are at higher risk for hepatitis A. About three-quarters of travel-related cases in the United States, are due to travel to Central or South America. Outbreaks can occur in men who have sex with men communities. Outbreaks also have occurred in methamphetamine users. Hepatitis A is typically transmitted from person to person through the fecal-oral route. Occasionally, foodborne transmission occurs when an HAV-infected food handler contaminates food that is not later cooked. Food handler associated outbreak characteristics include the presence of an HAV infected food handler who worked while infectious and had contact with uncooked food or food after it had been cooked, secondary cases among other food handlers who ate food contaminated by the index case and low attack rates in patrons. The hepatitis A rate in the United States in 2006 was 1.2 cases per 100,000 and 3,579 acute symptomatic cases were reported. The incidence rate was two to four times higher for Hispanics than non-Hispanics. The most commonly reported risk factor was international travel, that was reported by 15 percent of cases overall. Most of the travel was to Mexico and Central and South America. Ten percent of cases reported sexual and household contact with a case of hepatitis A. For 2006 cases, 73 percent of infected persons had jaundice, 33 percent were hospitalized and 0.3 percent died with acute hepatitis A.

Case definition The CDC case definition for a case of hepatitis A is used in Illinois: an illness with a discrete onset of symptoms and jaundice or elevated serum aminotransferase levels, and IgM anti-HAV positive serology.

Descriptive epidemiology

• Number of cases reported in Illinois in 2006 – 109 (five-year median = 186) (see Figure 46). • Age - Incidence was highest in 10- to 19-year-olds (1.6 per 100,000) (mean age = 31) followed by the 5- to 9- year-olds (1.5 per 100,000) (see Figure 47). The overall incidence rate for hepatitis A was 0.9. • Gender – Fifty-five percent of cases were female. • Race/ethnicity - Seventy percent were white, 3 percent African American, and 26 percent other races; 44 percent were Hispanic. Hispanics were overrepresented in the case population (44 percent) as compared to the Illinois population (12 percent).

95 • Employment - Six hepatitis A cases were food handlers. • Seasonal variation - Cases increased in summer months and December (see Figure 48). • Geographic variation – Twenty-three counties reported cases. Cook County reported the highest number (54 cases). • Risk factors – Risk factors included household contact with a hepatitis A case, nine (11 percent), travel outside the United States or Canada, 60 (59 percent) and consumption of raw shellfish, nine (9 percent). Most travelers had visited the area of Mexico, Central or South America and the Caribbean (41 of 60 cases) especially Mexico (32 cases). Two individuals reporting being MSM. • Symptoms/outcomes – Seventy-six percent of reported cases were jaundiced. Forty-two percent of cases were hospitalized. Two deaths were linked to acute hepatitis A. • Reporters – Forty-five percent of cases were reported by hospitals and 42 percent were reported by laboratories.

Summary Hepatitis A is the most commonly reported acute infectious hepatitis in Illinois. The incidence rate (0.9 per 100,000) was lower than the national incidence (2.7 per 100,000). The number of cases reported in 2006 was lower than the five-year median. The number of cases has been decreasing dramatically in the last five years. This may be due to the greater availability of HAV vaccine. The mean age of cases was 31 years, although the highest incidence (1.6 per 100,000) in 2006 occurred in 10-to-19-year- olds. Hispanics were overrepresented in hepatitis A cases.

Suggested readings Fiore, A.E., Wasley, A., and Bell, B.P. Prevention of hepatitis A through active or passive immunization. Recommendations of the Advisory Committee on Immunization practices (ACIP). 2006; 55(RR-7):1-23. Novak, R. and Williams, I. Update: Prevention of hepatitis A after exposure to hepatitis A virus and in international travelers. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP): 2007; 56(41):1080-84. Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006. MMWR 57 (SS-2): 1-24.

96 Figure 46 . Hepatitis A Cases in Illinois, 2001-2006

500 441 400 262 300 186 176 200 130 109 100

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 47. Number of Hepatitis A Cases in Illinois by Age, 2006

30 20 10 0 Number of cases Numberof <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Year

Figure 48. Hepatitis A Cases in Illinois by Month, 2006

25 20 15 10 5

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

97 Hepatitis B

Background is a vaccine-preventable bloodborne and sexually transmitted virus. It is acquired by percutaneous and mucosal exposure to blood or body fluids from an infected person. Men who have sex with men (MSM) are at increased risk for hepatitis B. Approximately 35 percent of cases of acute hepatitis B occur in people who report no recognized risk factor. The most commonly reported risk factors for transmission in the United States are high-risk sexual activity and injection drug use. The incubation period is 45 to 180 days (average 60 to 90 days). Positivity for HBeAg is linked to an increased risk of hepatocellular carcinoma. Fewer than half of acute hepatitis B cases will have jaundice (less than 10 percent of children, and 30 percent to 50 percent of adults). The onset is usually insidious with anorexia, nausea, vomiting, abdominal discomfort, jaundice, occasional arthralgias and rash. Chronic HBV infection is found in about 0.5 percent of adults in North America. An estimated 15 percent to 25 percent of persons with chronic hepatitis B will progress to cirrhosis or hepatocellular carcinoma. A vaccine became available in 1982. In Illinois, hepatitis B vaccination in children was mandated in 1997. CDC also recommends vaccination for MSMs, certain travelers, injection drug users, heterosexuals with multiple sex partners or with sexually transmitted diseases, clients or staff in developmentally disabled institutions, health care workers with blood contact, some immigrants, hemodialysis patients, household contacts and sexual partners of hepatitis B virus carriers and male prisoners. During 2006, 4,713 acute hepatitis B cases were reported to CDC from across the United States. In the United States there has been an 81 percent decrease in hepatitis B since 1990. In 2006, the overall rate of acute hepatitis B was 1.6 per 100,000. The rate was highest in those aged 25 to 44 years of age (3.1 per 100,000) and the lowest in children younger than 15 years of age (0.02 per 100,000). At least one-third of cases reported at least one sexual risk factors (sexual contact with a person with known hepatitis B, multiple sexual partners or men who have sex with men). Intravenous drug use was reported by 16 percent of persons. Seventy percent were jaundiced, 40 percent were hospitalized and 0.8 percent died. The rate in males was 1.8 times higher than in females. The rate in African Americans was also higher than other races. In a 2003 study, 75 percent of health care workers were vaccinated against hepatitis B. In a study of hepatitis B integration and vaccination in six STD clinics in the United States, DuPage County had the highest hepatitis B vaccination rate of 56 per 100 client visits in 2002. The overall median rate of completion of the hepatitis B vaccination series in the six clinics was 31 percent.

Case definition The CDC case definition is used as the surveillance case definition for hepatitis B in Illinois: a clinical illness with a discrete onset of symptoms and jaundice or elevated

98 serum aminotransferase levels, and laboratory confirmation. Laboratory confirmation consists of IgM anti-HBc-positive (if done), or HbsAg-positive, and IgM anti-HAV- negative (if done).

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 132 confirmed acute cases (five-year median = 130) (see Figure 49). The overall one-year incidence rate of reported acute hepatitis B in Illinois was 1.06 cases per 100,000 population. In INEDSS, 131 confirmed acute cases are recorded for 2006 so this number will be used for the information provided below. • Age – Cases ranged in age from 17 to 74 years of age (mean age = 41 years) (Figure 50). • Gender – Sixty-eight percent were male. • Race/ethnicity – Fifty-two percent of cases were African American, 33 percent were white and 7 percent were Asian; 13 percent were Hispanic. • Geographic location – Cases were reported from 21 counties. Counties with the most cases included Cook (74 cases), St Clair (nine), Kane (six), Lake (six) and Peoria (six). • Seasonal trend – Cases were distributed in all months of the year. • Symptoms/outcomes - Sixty percent of cases were hospitalized. One case was fatal. • Reporters – Sixty-two percent of cases were reported by hospital personnel, excluding the hospital laboratory. Thirty-six percent of cases were reported by private or hospital laboratories.

Summary There were 131 confirmed acute hepatitis B cases reported in Illinois in 2006. Sixty percent were hospitalized and one case was reported to be fatal. There was a higher number of males reported with hepatitis B than females.

Suggested readings Harris, J.L. et. al. Hepatitis B vaccination in six STD clinics in the United States committed to integrating viral hepatitis prevention services. Pub Health Reports 2007;122:42-7. Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006. MMWR 57 (SS-2): 1-24.

99 Figure 49. Hepatitis B Cases in Illinois, 2001-2006

250 218 185 200 130 130 132 150 111 100 50

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 50. Age Distribution of Hepatitis B Cases in Illinois, 2006

40 30 20 10

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Year

100 Hepatitis C, Acute

Background Hepatitis C virus (HCV), an RNA virus, is the most common chronic bloodborne infection in the United States. There are at least six distinct genotypes of HCV; types 1a and 1b are most common in the United States. It is estimated that 1.8 percent of United States residents have been infected with HCV. The incubation period for HCV ranges from two weeks to six months, most commonly six to nine weeks. Many individuals are asymptomatic and only a small proportion become jaundiced. Forty percent of infected adults are symptomatic, and 85 percent of adults with acute hepatitis C develop persistent infection. Acute hepatitis C is uncommon. The most efficient route of transmission is by direct percutaneous exposure (e.g., blood or blood product transfusion, organ or tissue transplants, and sharing of contaminated needles between injection drug users [IDUs]). Low efficiencies of transmission occur from sexual and household exposure to an infected contact. Transmission of HCV has been reported from patient to health care worker. The majority of HCV cases are in IDUs. The virus has been shown to be transmitted by the use of shared drug preparation equipment such as drug cookers and filtration cotton. In the United States, injection drug use accounts for 60 percent of HCV infection, sexual contact (20 percent) and other exposures (household, perinatal and occupational) for 10 percent. Ten percent of cases have no identified risk factor. The rate of transmission after needle-stick injury from a known infected person is less than 10 percent. The prevalence of HCV in non-injection drug users in a study in Italy was 20 percent. Routine screening for HCV infection is recommended only for persons who have a history of ever injecting drugs, recipients of clotting factor concentrates prior to 1987, recipients of blood transfusions or solid-organ transplants prior to July 1992, and chronic hemodialysis patients. Screening is also recommended for sex partners of HCV-infected persons, infants 12 months or older who were born to HCV-infected women, and health care workers after accidental needle-sticks or mucosal exposure to anti-HCV-positive blood. There is no vaccine or effective post-exposure prophylaxis to prevent HCV infection. Diagnostic tests for HCV infection include serologic assays for antibodies and molecular tests for viral particles. Screening tests for HCV include enzyme immunoassays (EIAs) to measure anti-HCV antibody. While these tests are highly sensitive, they do not distinguish between acute, chronic or resolved infections. False- positive results are common, resulting in the need for supplementary testing. Diagnostic testing for HCV should include use of both an enzyme immunoassay (EIA) and supplemental or confirmatory testing with a more specific assay such as the recombinant immunoblot (RIBA, Chiron Corporation). RIBA results are reported as positive, indeterminate or negative. It is not as sensitive as the EIA and should not be used for screening. In the United States, 802 acute hepatitis C cases were reported to CDC (0.3 per 100,000). The most common risk factor reported was intravenous drug use reported by 54 percent. In 2006, 66 percent of persons reported jaundice, 41 percent were

101 hospitalized and 0.2 percent died.

Case definition The CDC case definition, which is used in Illinois, is a discrete onset of symptoms with either jaundice or liver enzymes (ALT or AST) greater than 2.5 x upper limit of normal and negative serology for acute hepatitis A and hepatitis B and positive for HCV antibody confirmed by a supplemental test (or simply positive for HCV by the supplemental test).

Descriptive epidemiology • Number of cases in Illinois in 2006 – Thirteen cases of acute hepatitis C were reported. • Age – Acute hepatitis C cases ranged from 10 to 68 years of age (mean age = 44). • Gender – Forty-six percent of acute hepatitis C cases were male. • Race/ethnicity - For acute hepatitis C cases, 83 percent of cases were white, and 17 percent were African American; 11 percent were Hispanic. • Geographic variation – Eleven counties reported cases. • Reporter – Forty-six percent of cases were reported by hospitals and 31 percent by laboratories. • Symptoms/outcomes – Sixty-seven percent of 12 acute hepatitis C cases with histories were hospitalized, and no cases were fatal.

Summary Acute hepatitis C is an uncommon disease, only 13 cases were reported in Illinois in 2006.

Suggested readings Hahn, J. A. Sex, drugs, and hepatitis C virus. JID 2007; 195:1556-59. Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006. MMWR 57 (SS-2): 1-24.

102 Hepatitis C, Chronic or Resolved

Background The World Health Organization estimates that 170 million people worldwide are infected with HCV. The hepatitis C virus can cause chronic hepatitis, cirrhosis and hepatocellular carcinoma. Among adults who had acute hepatitis C, 26 percent to 50 percent developed chronic active hepatitis and 3 percent to 26 percent developed cirrhosis. In a study of transfusion related hepatitis C in the United States from 1968 through 1980, the risk for developing cirrhosis was 17 percent. Heavy alcohol use increased the risk for developing cirrhosis. Anti-HCV positive persons had a 5- to 50- fold higher risk of primary hepatocellular carcinoma compared to anti-HCV negative patients. These sequelae typically take 20 or more years to develop. Hepatitis C is the most common indication for liver transplantation in adults and accounts for about 40 percent of all transplants in the United States. About 50 percent to 80 percent of patients with pretransplantation viremia develop hepatitis in the liver graft. Persons with chronic hepatitis C should not drink alcohol and should be vaccinated for hepatitis A and hepatitis B. HCV-positive persons should not donate blood, organs, tissues or semen. There is insufficient data to recommend that infected persons change sexual practices with steady partners. HCV-positive household members should not share toothbrushes or razors. Treatment for hepatitis C may be recommended for persons with elevated serum alanine aminotransferase (ALT) and tests that indicate the presence of circulating HCV RNA. HCV RNA levels do not correlate with grade or stage of disease. HCV is divided into six genotypes. Genotype is a predictor of response to therapy. Genotype 1a and 1b HCV infection, the most common types in the United States, have a poorer response to therapy than other types. Response to therapy is higher in those with genotypes 2 and 3.

Descriptive epidemiology • Number of cases in Illinois in 2006 – There were 6,843 cases of chronic or resolved hepatitis C reported. Because this is a chronic disease, these cases may have acquired infection years ago and the number of cases, is just the number of cases reported in 2006, not necessarily the year of exposure or onset of any illness. • Age – Chronic or resolved hepatitis C cases ranged from one to 96 years of age (mean age = 50 years). • Gender – Sixty-five percent of chronic or resolved hepatitis C cases were male. • Race/ethnicity - For chronic or resolved hepatitis C cases, 67 percent of cases were white, 27 percent were African American and 5 percent were other races; 6 percent were Hispanic. • Geographic variation – Ninety-seven counties reported cases. The 10 counties reported the most cases were Cook (2,893), Winnebago (322), Dupage (273), Will (270), Lake (240), Sangamon (211), St. Clair (177), Kane (162), Peoria (158) and Macon (133).

103 • Genotype – Genotype was only available for 198 cases. The most common genotypes reported were 1b (66 cases), 1a (37), 3a (35), 2b (25) and 1 (14). Genotypes reported in five or less persons included 2, 3, 4,1c, 2a, 2a/2c and mixed. • Risk factors - For chronic or resolved hepatitis C, risk factors included history of injection drug use (41 percent of 2,267 cases), cocaine or other street drugs (46 percent of 2,246 cases), tattoos or piercings (49 percent of 2,208 cases), blood exposures (13 percent of 2,225), contact with other hepatitis C cases (16 percent of 1,824) and blood transfusions (25 percent of 2,082). • Symptoms/outcomes – Twenty-two percent of 3,166 chronic or resolved hepatitis C cases with histories were hospitalized, and 11 cases were fatal. • Reporter – Fifty-six percent of cases were reported by private laboratories, 25 percent by hospital personnel other than laboratory personnel and 12 percent by hospital laboratory personnel.

104 Histoplasmosis

Background Histoplasmosis is a systemic fungal disease caused by Histoplasma capsulatum. Transmission occurs through inhalation of the organism. The incubation period ranges from three to 17 days. Signs and symptoms of histoplasmosis include fever, headache, muscle aches, cough and chest pain. Patients who have underlying lung disease may develop chronic lung disease after H. capsulatum infection. Bird and bat droppings are beneficial to the growth of the organism. Diagnosis of infection can be through culture or serology. The M precipitin alone indicates active or past infection. The H precipitin indicates active disease or recent infection. Histoplasmosis can be a severe infection in persons with HIV or other immunocompromising conditions. Approximately 5 percent of persons with AIDS who live in endemic areas may develop histoplasmosis, which frequently disseminates.

Case definition Histoplasmosis is not a nationally notifiable disease. The case definition for histoplasmosis in Illinois is either: 1) Isolation of the organism from a clinical specimen in patients with acute onset of flu-like symptoms, or 2) In patients with flu-like symptoms, hilar adenopathy and/or patchy infiltrates found on chest radiograph, if done, and at least one of the following: a. M or H precipitin bands positive by immunodiffusion b. A four-fold rise between acute and convalescent complement fixation (CF) titers c. A single CF titer of >1:32 d. Demonstration of histoplasma polysaccharide antigen by radioimmunoassay (RIA) in blood or urine, or demonstration of organisms by staining blood specimens or biopsy material

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 112 (five-year median = 72) (see Figure 62). At least 31 (28 percent) of these cases were in immunocompromised persons; therefore, it is not possible to determine whether they represent new infections or reactivation of previous infections. • Sex – Sixty-four percent of cases were male. • Age - Mean age was 42 years (Figure 63). • Race/ethnicity – Seventy-three percent were white, 21 percent were African Americans, and 5 percent were other races; 10 percent were Hispanic. • Disease type – Twenty cases had disease described as disseminated histoplasmosis. Of 67 cases with chest x-ray results, 58 (88 percent) had abnormalities. • Symptoms – Symptoms included difficulty breathing (71 percent); fever (65 percent);

105 cough (64 percent), night sweats (51 percent) and chest pain (46 percent). Twenty- seven percent reported being current smokers. • Diagnosis – All cases were reported as confirmed; Twenty-seven cases (24 percent) were confirmed by culture. Cultures were positive from blood (eight cases), lymph node (four), lung (three), bone or bone marrow (two), bronchial wash (two), other (five) and unknown (two). Two cases had positive smears from the following sources blood (one) and lung (one). Thirty-seven cases were M band positive by immunodiffusion. Forty cases had complement fixation titers of at least 1:32; 17 of these also were positive by M band testing. For 29 cases, more than one diagnostic method was positive. • Seasonal variation - No seasonal trend was identified (See Figure 64). • Geographic variation - The three counties reporting the most cases were Cook (29 cases), Sangamon (10 cases) and Champaign (eight cases). • Reports of exposure to the following (not reported for all cases) - Dirt arenas (21 percent), construction (20 percent), excavation (11 percent), potting soil (10 percent), plowing (9 percent), bird raising (9 percent) and caves (4 percent). • Outcomes – Sixty-seven (63 percent) of cases were hospitalized; three cases were fatal. • Outbreaks - One outbreak was reported in 2006. Two Chicago residents traveled out-of-state and acquired histoplasmosis. • Reporting- Fifty-three percent of cases were reported by hospital personnel and 37 percent by laboratories.

Summary In 2006, 112 cases were reported as compared to 72 in 2005. One small outbreak was reported. The most common symptoms were difficulty breathing, fever and cough.

Figure 62. Histoplasmosis Cases in Illinois, 2001-2006

112 120 98 96 100 72 80 59 57 60 40

Number of of Number cases 20 0 2001 2002 2003 2004 2005 2006 Year

106 Figure 64. Histoplasmosis Cases in Illinois by Month, 2006

20 15 10 5

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of onset

107 Legionellosis

Background Legionella spp are linked with warm water and biofilms that support the growth and survival of the organism. There are 48 species of Legionella and several serotypes. L. pneumophila serotype 1 is responsible for most lower respiratory tract infections. However, 19 other Legionella species have been documented as human pathogens based on isolation from clinical material. The two major clinical manifestations of infection with Legionella bacteria are Legionnaires’ disease (legionellosis) and Pontiac fever. Legionellosis may be epidemic or sporadic, nosocomial or community acquired. Approximately 4 percent of persons with community acquired pneumonia test positive by Legionella urinary antigen. The incubation period is two to 10 days (average five to six days). For Pontiac fever, it is five to 66 hours (average 24-48 hours). Initial symptoms of both are anorexia, myalgia and headache often followed by a nonproductive cough and diarrhea. Patients with legionellosis clinically have pneumonia and abnormal chest radiographs. Legionellosis most often occurs in those who are immunocompromised due to disease or aging. Risk factors are underlying medical conditions such as human immunodeficiency virus, organ transplantation, renal dialysis, diabetes, chronic obstructive pulmonary disease, cancer, immunosuppressive or smoking. Pontiac fever is an acute, febrile illness with a high attack rate, short incubation period and rapid recovery. Most cases are sporadic (not associated with a known outbreak). Outbreaks have been associated with aerosol producing devices such as whirlpool spas, showers, humidifiers, respiratory care equipment, evaporative condensers, air conditioners, grocery store mist machines and cooling towers and have occurred in industrial settings. Approximately 20 percent of all Legionnaires’ disease cases are outbreak related. Many are thought to be associated with potable water systems in hotels or whirlpool spas in hotels or on board cruise ships. Legionella urine antigen testing and culture of respiratory secretions are useful for diagnostic testing. The urine antigen test provides rapid diagnosis for L. pneumophila serogroup 1 but will not provide an isolate to compare to clinical and environmental isolates gathered during outbreak investigations. Testing for Legionella species is not performed by the IDPH laboratory. Most test results among reported cases are from hospital or commercial laboratories. In 2006, 2,834 cases of legionellosis were reported to CDC from state health departments. CDC has a travel-associated Legionella surveillance e-mail address used by state health departments to report cases of Legionella that have traveled outside their state. From 1990 through 2005, the number of cases reported to CDC by year ranged from 1,094 to 2,291. The incidence increased over time especially in the northeastern United States and the South. Cases were most commonly reported in those 45 to 64 years of age. Rates in males exceeded females.

Case definition A confirmed case in Illinois is one that meets the CDC case definition, i.e., a

108 clinically compatible illness with laboratory confirmation of disease by 1) isolation of Legionella from lung tissue, respiratory secretions, pleural fluid, blood or other normally sterile sites; or 2) demonstration of a fourfold or greater rise in the reciprocal indirect fluorescence (IF) antibody titer to greater than or equal to 128 against L. pneumophila serogroup 1 between paired acute and convalescent phase serum specimens; or 3) demonstration of L. pneumophila serogroup 1 in lung tissue, respiratory secretions, or pleural fluid by direct fluorescent antibody (FA); or 4) demonstration of L. pneumophila serogroup 1 antigens in urine by radioimmunoassay (RIA) or enzyme-linked immunoassay (ELISA).

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 127 (five-year median = 150) (Figure 65). All were confirmed. CDC reported 128 cases for Illinois for 2006, but there are 127 in the Department records. The information below is based on 127 cases. • Age – Seventy-six percent of cases were greater than 50 years of age (see Figure 66). • Gender – Eighty (63 percent) cases were male. • Race/ethnicity – Four percent reported Hispanic ethnicity. • Seasonal - An increase in cases occurred in September (Figure 67). • Geographic distribution – Thirty counties reported cases. Fifty-eight cases (46 percent) resided in Cook County. • Risk factors - Twenty percent of 95 cases stayed in a hotel overnight in the two weeks prior to onset. At least one underlying health problem among diabetes (six), cancer (four), transplant (one), corticosteroid therapy (seven), smoking (15) or multiple underlying conditions (17) was reported by 50 of 64 (78 percent) cases with that information; percent reported no underlying health problems. No cases were reported to be nosocomial. Nine persons were reported as residing in a residential facility. • Diagnosis - Cases were diagnosed through urine antigen only (89), serology only (13), culture of respiratory secretions or blood only (six), direct fluorescent antibody of respiratory secretions only (three), multiple methods (five) or unknown (11). • Outcomes - Hospitalization was required for 113 of 119 cases with information available; Ninety-six cases reported X-ray confirmed pneumonia, two did not have pneumonia and for 29 cases the information was not available at the time of this report; Five fatalities were reported among cases. • Reporting – The majority of cases with information available (76 percent) were reported by infection control professionals. • Outbreaks – One outbreak was reported in 2006. Two confirmed cases of Legionella were linked to a hotel with a pool and spa in Logan County. After an investigation which involved contacting hotel guests, a total of three cases of Legionnaires’ disease and 40 cases of Pontiac fever were identified. Five cases were laboratory confirmed. A hotel pool and spa were culture positive for and L. macearchernii. Persons spending time in the pool area were at higher risk for disease.

109

Summary In 2006, there was a decrease in cases of legionellosis, as compared to the five- year median. Seventy-eight percent of 64 cases had pre-existing medical conditions. There was one outbreak of legionellosis in 2006.

Suggested readings Ng, Victoria, et. al. Our evolving understanding of legionellosis epidemiology: Learning to count. CID 2008:47:600-2. Neil, K. and Berkelman, R. Increasing incidence of legionellosis in the United States, 1990-2005: Changing epidemiologic trends. CID 2008;47:591-9. Smith, P., et al. Surveillance for travel-associated Legionnaires disease – United States, 2005-2006.

Figure 65. Legionellosis Cases in Illinois, 2001-2006

150 127

100 66 50 55 50 24 28

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 66. Age Distribution of Legionellosis Cases in Illinois, 2006

80 60 40 20

Number of cases Numberof 0 <30 30-39 40-49 50-59 >59 Age groups

110 Figure 67. Legionellosis Cases in Illinois by Month, 2006

40 30 20 10

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of onset

111 Lyme Disease

Background Lyme disease is a tickborne zoonotic disease caused by the bacterium Borrelia burgdorferi sensu lato. The reservoir is the black-legged tick (Ixodes scapularis), commonly called the deer tick. Human disease is thought to be primarily caused by nymphal tick bites, usually in late spring or summer. Babesiosis and ehrlichiosis also are transmitted by the same tick. In the Midwest, wild rodents and other animals maintain the transmission cycle. Deer are the preferred host of the adult tick. Laboratory studies indicate ticks must be attached for at least 24 hours for transmission to humans to occur. Experiments in animals have shown that most often the tick must feed at least 48 hours before the risk of transmission becomes substantial. Lyme disease is characterized by a rash-like skin lesion called erythema migrans (EM) that may be followed by cardiac, neurologic and/or rheumatologic involvement. The incubation period for EM ranges from three to 32 days (mean: seven to 10 days) after tick exposure; it is present in 80 percent to 90 percent of case patients. Erythema migrans may be characterized by a homogenous rash rather than a target appearance because of early presentation for treatment. EM is the most common clinical manifestation of Lyme disease. Early manifestations include fever, headache, fatigue, migratory arthralgias and possibly lymphadenopathy. It can take approximately two to four weeks or longer for antibodies to be detected by blood tests, so these tests are not required for patients diagnosed with EM in the public health surveillance case definition. There were 19,931 cases of Lyme disease (6.75 per 100,000) reported in 2006 in the United States, mainly from the Northeast, mid-Atlantic and north-central regions of the country. Ten states - Connecticut, Delaware, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Rhode Island and Wisconsin - accounted for 93 percent of all cases reported. The majority of cases had onset in June, July or August. Manifestations of Lyme disease included erythema migrans (69 percent), arthritis (32 percent), neurologic (12 percent) and AV block (0.8 percent). A study of electronic laboratory reporting from 2001 through 2004 in New Jersey showed that only 29 percent of Lyme disease electronic lab reports were confirmed as Lyme disease upon investigation. Effective prevention measures include personal protective measures (tick checks, repellents) and decreasing tick exposure. The Infectious Disease Society of America has advanced the recommendation that antimicrobial prophylaxis can be offered after a recognized tick bite if the following conditions are true: 1) the attached tick is identified as Ixodes and was attached for greater than 36 hours, 2) prophylaxis can be started within two hours of when the tick was removed, 3) the tick infection rate in the area is 20 percent or greater and 4) is not contraindicated. In a case- control study of Lyme disease in Connecticut from 2000 to 2003, cases were less likely to report using protective clothing outdoors and to use tick repellents on their skin or clothes. B. burgdorferi infected Ixodes scapularis ticks were recovered from Cook,

112 Dupage and Lake Counties and one-third of ticks were infected.

Case definition The surveillance case definition for Lyme disease in Illinois is the CDC definition: 1) erythema migrans, or 2) at least one late manifestation (musculoskeletal system, nervous system or cardiovascular system) and supportive laboratory evidence of infection or laboratory confirmation, i.e., isolation of B. burgdorferi from a clinical specimen, or demonstration of diagnostic immunoglobulin M or immunoglobulin G antibodies to B. burgdorferi in serum or cerebrospinal fluid (CSF). A two-test approach using a sensitive enzyme immunoassay or immunofluorescence antibody followed by Western blot is required by the Department for confirmation of non-EM cases.

Descriptive epidemiology During 2006, increased numbers of cases occurred in the northeastern part of Illinois where deer ticks became established. Wisconsin also reported an increase in Lyme disease cases in 2006.

• Number of cases reported in Illinois in 2006 – One hundred and ten (five-year median = 71) (See Figure 68) cases were reported. All cases were confirmed. The incidence was 0.9 per 100,000. • Age - Cases ranged in age from 1 to 18 years of age (mean= 38) (Figure 69). • Gender – Sixty-four percent were male. • Race/ethnicity – Of the cases for which race is known, 94 (99 percent) were white; two cases identified themselves as Hispanic. • Seasonal distribution – Lyme disease case onsets were most common from May through July (Figure 70). • Geographic distribution - Forty-one cases reported a single Illinois county as an exposure locale are mapped in Figure 71. One case reported multiple Illinois counties as exposure sites. Four cases reported Illinois plus another state as exposure sites. Sixty cases reported non-Illinois exposure locations including Wisconsin (48), Michigan (four), Pennsylvania (two), Massachusetts (one), Minnesota (one), Maryland (one), multiple states (three) and Poland (one). For two cases no exposure location could be identified. Twenty counties reported residents with Lyme disease. The top four counties reporting residents with Lyme disease included Cook County (35 cases), Jo Daviess (21 cases), Will (11) and DuPage (10). • Tick Distribution – A map of Illinois with the distribution of known Ixodes scapularis (the vector for Lyme disease) is provided (Figure 72). • Symptoms - Qualifying manifestations were EM (90, 82 percent), rheumatologic signs () and neurologic signs such as Bell’s palsy (). Six percent of cases were hospitalized; no deaths were reported in cases. • Reporting – The three top reporters of Lyme disease cases were laboratory staff (53 percent), clinics (21 percent) and infection control professionals (20 percent). • Tick exposure – Twenty-five of 63 (40 percent) of cases reported a tick bite before

113 illness onset. Ninety-three of 94 (99 percent) of cases reported being in a tick habitat. The three most common sites of tick exposure habitat were own property (28 cases), campgrounds (23 cases) and parks and nature preserves (18 cases). • Past incidence - In Illinois, reported Lyme cases for previous years are as follows: 1991 (51), 1992 (41), 1993 (19), 1994 (24), 1995 (18), 1996 (10), 1997 (13), 1998 (14), 1999 (17), 2000 (35), 2001(32) and 2002 (47), 2003 (71), 2004 (87) and 2005 (127).

Summary For the cases reported in Illinois residents during 2006, EM was the most common qualifying manifestation for Lyme disease. The number of cases peaked in the summer months. The incidence in Illinois (1.0 per 100,000) is much lower than the national average (6.7 per 100,000) for 2006. The number of reported cases of Lyme disease decreased for the first time since 1996.

Suggested readings Anon. Effect of electronic laboratory reporting on the burden of Lyme disease surveillance – New Jersey, 2001-2006. MMWR 2008; 57(2): 42-45. Auwaerter, P.G. Point: Antibiotic therapy is not the answer for patients with persisting symptoms attributable to Lyme disease. CID 2007;45:143-8. Bacon, R.M., et. al. Surveillance for Lyme disease – United States, 1992-2006. MMWR 2008; 57(SS-10).1-9. Jobe, D.A. et al. Lyme disease in urban areas, Chicago (letter). EID [serial on the internet] 2007. Available from http://www.cdc.gov/EID/ content/ 13111/1799.htm. Vazquez, M., et al. Effectiveness of personal protective measures to prevent Lyme disease. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from http://www.cdc.gov/EID/content/14/2/210.htm. Wormser, G.P. et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: Clinical practice guidelines by the Infectious Disease society of America. CID 2006;43:1089-134.

Figure 68. Lyme Disease Cases in Illinois, 2001-2006

150 127 110 87 100 71 47 50 32

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

114 Figure 69. Age Distribution of Lyme Cases in Illinois, 2006

30

20

10

Number of cases Numberof 0 <11 yr 11-20 yr 21-30 yr 31-40 yr 41-50 yr 51-60 yr >60 yr Age groups

Figure 70. Lyme Disease Cases in Illinois by Month, 2006

50 40 30 20 10

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of onset

115

Figure 71. Illinois Map of Reported Exposure Location of Lyme disease Cases by County, 2006

Jo DaviessStephensonWinnebago McHenry Lake 21 0 0 0 0 Boone Carroll Ogle 0 1 7 Kane DeKalb 0 DuPage 0 Whiteside Lee 1 0 0 Cook Kendall 1 0 Will Rock Island Bureau Henry 2 0 0 La Salle 0 0 Grundy Mercer 3 0 Kankakee Stark 0 0 Marshall Knox 0 Livingston Warren 0 Henderson Peoria 0 Iroquois 0 0 Woodford 2 0 McDonough Ford 0 Tazewell 0 Fulton McLean Hancock 0 0 0 0 Mason Champaign Schuyler De Witt Vermilion 0 Logan 0 0 0 0 Menard 0 Piatt Adams Brown Cass 0 0 0 0 0 Macon Sangamon 0 Douglas Morgan Edgar 0 Moultrie 0 Pike Scott 0 0 0 0 Christian 0 Coles 0 Shelby 0 Greene 0 Clark 0 Macoupin Cumberland 0 Calhoun 0 Montgomery 0 1 Jersey 0 Effingham Jasper Crawford 0 Fayette 0 Bond 0 0 0 Madison 0 Clay 0 RichlandLawrence 0 Clinton Marion 0 1 1 St. Clair 0 Wayne Wabash 0 Washington 0 Jefferson 0 Monroe 0 Edwards 0 0 0 Randolph Perry White 0 0 Franklin 0 0 Jackson 0 SalineGallatin Williamson 0 0 0 Hardin UnionJohnson Pope 0 0 0 0 AlexanderPulaski Massac 0 0 0

116 Figure 72. Tick Distribution Map

117 Malaria

Background

Malaria is a very important global . It is endemic in more than 100 countries. The incubation period may range from seven days to 10 months. Symptoms of malaria include fever, headache, muscle aches, fatigue, diarrhea, and vomiting. Four species of Plasmodium (P. vivax, P. falciparum, P. malariae and P. ovale) cause disease in people. P. vivax malaria is the most common form. P. falciparum is the most common species in tropical areas and causes the most malaria deaths. The majority of malaria-endemic countries are in sub-Saharan Africa, Southeast Asia and Latin America. More than 90 percent of the incidence of malaria in the world occurs in sub-Saharan Africa and two-thirds of the remaining cases occur in India, Myanmar, Afghanistan, Vietnam and Colombia. The highest risk of malaria is for travelers to sub-Saharan Africa, Papua New Guinea and the Solomon Islands. About 90 percent of P. falciparum infections are acquired in Africa. More than 70 percent of P. vivax infections are due to exposures in Asia or Latin America. In a study of travelers visiting GeoSentinel clinics in the world from 1997 through 2006, the most common diagnosis for persons returning to their homes with fever was malaria. P. falciparum was diagnosed in 66 percent of persons with malaria. The most common destinations were Oceania, the Pacific Islands or sub-Saharan Africa. Immunity lasts less than two years once a person leaves an endemic area. Many persons who travel back to their home country assume they are immune. Identification of the malaria species is important because treatment can differ. For example, disease caused by P. falciparum has a more serious prognosis and must be treated differently. Untreated P. falciparum can progress to coma, renal failure, and death. The majority of fatal cases in the United States are due to not using correct chemoprophylaxis, incorrect initial chemotherapy and delays in malarial diagnosis. One of the most important diagnoses to consider in recent travelers with fever is malaria. Imported malaria cases occur in Illinois when someone with the disease immigrates to the United States or when someone who travels overseas uses inadequate chemoprophylaxis. Persons traveling to malarious areas should take recommended chemoprophylaxis regimens and use appropriate personal protective measures against mosquito bites (using mosquito nets at night when accommodations do not protect against mosquitos and repellents). The risk of malaria depends on geographic location of travel, urban versus rural stay, type of accommodations, duration of stay, time of the year, activities, elevation and compliance with preventive measures. In the United States, malaria is transmitted predominantly by the bite of an infective female anopheline mosquito to travelers while overseas. Other less common methods include infected blood products, congenital transmission or local mosquito borne transmission. Malarial infection or relapse during pregnancy results in risk to the mother and fetus, including maternal anemia, spontaneous abortion, perinatal mortality,

118 low birth weight, and prematurity. Symptoms in newborns include fever, poor appetite, irritability, and lethargy and can mimic sepsis. Malaria should be considered in the differential diagnosis of illness in persons with 1) fever and a history of travel to areas where malaria is endemic, including immigrants, 2) fever of unknown origin, regardless of travel history, or in 3) ill neonates and young infants with fever and mothers who have immigrated or traveled to areas where malaria is endemic. The majority of malaria infections in Illinois are caused by travel to areas with ongoing transmission. In 2006, 1,564 malaria cases were reported in the United States including six fatal cases. The species of malaria identified in these cases was falciparum (39 percent), vivax (18 percent), malariae (3 percent) and ovale (3 percent). In 37 percent of cases the species was unknown. Malaria is transmitted in parts of Africa, Asia, the Middle East, Central and South America, the island of Hispaniola and Oceania. The majority of infections in the United States were acquired in Africa (70 percent), followed by Asia (18 percent) and the (10 percent). Sixty-seven percent of cases had taken no chemoprophylaxis. Among foreign residents for whom the purpose of travel was known, 58 percent were recent immigrants or refugees and 17 percent were visiting friends or relatives in the United States.

Case definition Illinois uses the CDC case definition. A confirmed case is a person (symptomatic or asymptomatic) with an episode of microscopically confirmed malaria parasitemia diagnosed in the United States, regardless of whether the person experienced previous episodes of malaria while outside the country.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 83 (five-year median = 61) (see Figure 73). All were confirmed cases. • Age – Sixty-nine percent of cases occurred in persons from 10 to 39 years of age. The mean age of cases was 35 (Figure 74). • Sex – Sixty percent of cases were male. • Race/ethnicity - Fifty-two percent were African American, 20 percent were white, 18 percent were Asian and 10 percent were other races; no cases were reported to be of Hispanic ethnicity. There were significantly higher proportions of African Americans with malaria compared to their presence in the Illinois population and significantly lower proportions of whites and Hispanics with malaria compared to the Illinois population. • Geographic location – Malaria cases were reported from residents of 17 counties. The majority were reported from Cook County (58 percent). • Seasonal variation - Cases of malaria were reported in greater numbers in the summer (Figure 75). • Speciation - The malaria species identified in the reported cases were P. falciparum (39 cases, 51 percent of cases with known species), P. vivax (30

119 cases, 39 percent), P. malariae (five cases, 6 percent), P. ovale (one case, 1 percent) and unknown (seven cases) (Figure 76).

• Treatment/outcomes - Fifty-one of 79 cases (64 percent) were hospitalized. No cases are known to have been fatal. • Risk factors - The major risk factor for infection is travel outside the United States. Specific information was available for 78 of the 2006 cases. The Asian countries reported by cases as travel destinations were India (19 cases), Papua New Guinea (one case) and Nepal (one case). In Africa, the following travel destinations were reported for 50 cases: Nigeria (26 cases), Ghana (six cases), Cameroon (four cases), Uganda (three cases), Tanzania (one case), Liberia (one case), Madagascar (one case), Ethiopia (one case), Guinea (one case) and multiple African countries (six cases). One case reported a travel destination of South America (Brazil). Two cases reported travel to the Middle East (one case to Iraq and one to Afghanistan). Two cases reported travel destinations in multiple continents. For four persons the location of travel was unknown. For one person, travel history was unknown. • Of the 26 cases reporting travel to Nigeria, 20 were infected with P. falciparum, two with P. malariae, and none with P.vivax. Three cases were not speciated. Of the six cases who visited Ghana, five had P. falciparum and one case had P.vivax. Of the 19 cases reporting travel to India, 17 were infected with P. vivax, one with P. falciparum and one with multiple species. • Cases provided the following reasons for travel overseas: visiting friends or relatives overseas (26), refugee or adoption (nine), visiting United States (six), missionary work (five), business (four), tourism (three), military (two), other (eight), and unknown (19). • Reporting – Sixty-three of 83 cases (73 percent) were reported by hospitals and 18 (22 percent) were reported by laboratories.

Summary There were 83 reported cases of imported malaria identified in Illinois in 2006, the sixth highest number of cases among the states. This was higher than the annual median (61 cases) for the previous five years. African Americans and Asians made up a higher proportion of persons with malaria than in the Illinois population. Laboratories should forward blood smears to the Department’s laboratory for verification of species. Laboratories should be thorough in identifying the species of this parasite because treatment differs by species (e.g., P. vivax and P. ovale require additional treatment with primaquine to prevent relapses) and simultaneous infection with more than one species does occur.

Suggested readings Wilson, M.E. et al. Fever in returned travelers: Results from the GeoSentinel surveillance network. CID 2007;44:1560-8.

120

Figure 73. Malaria Cases in Illinois, 2001-2006

100 83 71 74 80 61 60 46 47 40 20

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 74. Age Distribution of Malaria Cases in Illinois, 2006

25 20 15 10 5

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age Group

Figure 75. Malaria Cases in Illinois by Month, 2006

15

10

5

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Onset

121 Figure 76. Species of Malaria Identified, Illinois, 2006 P. ovale 1% P. malariae 6% P. F. vivax falciparum 40% 53%

122 Measles

Background Measles is a highly communicable viral disease with humans as the only natural host for the infection. Transmission most commonly occurs through airborne spread or through direct contact with nasal or throat secretions of infected people. The incubation period is about 10 days, but varies from seven to 18 days. Infected individuals show fever, conjunctivitis, coryza, cough and Koplik’s spots on the buccal mucosa, along with a rash that appears on the third to seventh day. The disease can be prevented by proper . A two-dose is recommended in the United States, one at 12 to 15 months and one at school entry (4 to 6 years) or by 11 to 12 years. Sustaining high levels of vaccination is important to limit indigenous spread of measles from cases imported into the United States. Nationally, there were 55 cases reported to CDC; 95 percent were imported and additional cases occurred from these imported cases. For three cases, the source was classified as unknown because no link to importation could be identified. Four outbreaks occurred, all from imported sources. More than half (31 of 55) of cases were in adults aged 20 to 39 years of age.

Case definition A confirmed case in Illinois is one that meets the CDC definition, i.e., a case that is laboratory confirmed, or that meets the clinical case definition and is epidemiologically linked to a confirmed case. Laboratory confirmation consists of 1) isolation of measles virus from a clinical specimen, or 2) significant rise in measles antibody level by any standard serologic assay, or 3) positive serologic test for measles IgM antibody. The clinical case definition is an illness characterized by a generalized rash lasting at least three days, and a temperature of at least 101° F, and a cough or coryza or conjunctivitis.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – None.

Summary No cases of measles were reported.

123 Figure 74. Measles Cases in Illinois, 2001-2006

4 3 3 2 2 1 1 1 1 0

Number of cases 0 2001 2002 2003 2004 2005 2006 Year

124

Mumps

Background Mumps is transmitted by droplet spread and by direct contact with the saliva of an infected person. The incubation period is 12 to 25 days. This viral disease is characterized by fever and swelling and tenderness of salivary glands lasting two or more days and without other apparent cause. may occur in males and oophoritis in females. Winter and spring are the times of increased occurrence. Vaccination can prevent mumps. To prevent mumps a two-dose MMR vaccination series for all children (first dose at 12-15 months, second dose at 4-6 years of age). Two doses are recommended for school and college entry unless there is other evidence of immunity. In 2006, 6,584 mumps cases were reported to CDC. In 2006, the largest mumps outbreak in more than 20 years occurred in the United States. The majority of cases were reported from March to May. Eight-four percent of cases were from six Midwestern states (Illinois, Iowa, Kansas, Nebraska, South Dakota and Wisconsin). Eighteen to 24 year olds were most affected.

Case definition A confirmed case in Illinois is one that meets the CDC case definition: a clinically compatible illness that is laboratory confirmed, or that meets the clinical case definition and is epidemiologically linked to a confirmed or probable case. A laboratory-confirmed case does not need to meet the clinical case definition. The laboratory confirmation may consist of 1) isolation of mumps virus from a clinical specimen, or 2) a significant rise in mumps antibody level by a standard serologic assay, or 3) a positive serologic test for mumps IgM antibody. The clinical case definition is an illness with acute onset of unilateral or bilateral tender, self-limiting swelling of the parotid or other salivary gland, lasting more than two days, and without other apparent cause.

Descriptive epidemiology

• Number of cases reported in Illinois in 2006 - 798 (five-year median = 10) (Figure 75). Of the 798 cases, 336 were confirmed and 462 were probable. • Age - Mean age was 26 years (range was 1 years to 89 years). • Gender - Sixty-six percent were female. • Race/ethnicity – Eighty-six percent were white, 9 percent were African American, 3 percent were Asian and 2 percent were other races. Ten percent reported Hispanic ethnicity. • Geographic distribution - Cases resided in 67 counties. • Seasonal variation - Cases occurred from January through December. • Clinical syndrome – The mean duration of parotitis was seven days. • Outcome – Complications included orchitis (19), meningitis (two) and deafness (one). Twenty-six cases were admitted to the hospital. No fatalities were reported. • Immunization status – Of the cases reported in Illinois, 42 percent could

125 demonstrate history of two doses of mumps-containing vaccine, 14 percent had one dose and an additional 11 percent had an unsubstantiated number of mumps- containing doses. Of the 34 percent with no or unknown vaccination status, 17 percent were old enough to be unsure if they had actually ever been vaccinated, 11 percent had no history of vaccination and 6 percent failed to answer the question. • Outbreaks – An outbreak began in Iowa and involved many other states, including Illinois. Mumps viral isolates from six states were genotype G. The greatest number of onsets occurred in April, with more than 50 cases each week during April. Case rates were highest among students attending the following colleges: Southern Illinois University-Carbondale (22 percent), Augustana (11 percent), Northern Illinois University (10 percent), University of Illinois-Chicago and Loras (each 8 percent). The primary control strategy in the Illinois student population (95 percent coverage) was early diagnosis and exclusion for nine days following onset of parotitis or other significant symptoms associated with mumps.

Summary The mean age of the 798 reported mumps cases in 2006 was 26 years. There was a very large increase in mumps cases in the state over previous years due to a multi-state outbreak. A large outbreak started in Iowa college students, which spilled over into Illinois. Almost half reported being appropriately immunized.

Suggested readings Gershman, K. et. Al. Update: Multistate outbreak of mumps – United States, January 1-May 2, 2006. MMWR 2006;55(20):559-63.

Figure 77 . Mumps Cases in Illinois, 2001-2006

1000 798 800 600 400 200 21 18 8 10 10

Number of cases 0 2001 2002 2003 2004 2005 2006 Year

126 Figure 72. Age Distribution of Mumps Cases in Illinois, 2006

250 200 150 100 50

Numberof cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age Group

Figure 73. Mumps Cases in Illinois by Month, 2006

300

200

100

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Onset

127 Orf Background Orf is a viral cutaneous disease transmitted to human through contact with sheep or goats that are infected. The incubation period is usually three to six days. Skin lesions, usually on the face, arms or hands may last three to six weeks. Diagnosis is through typical lesions and history of contact with infected sheep or goats. Laboratory confirmation by polymerase chain reaction can be performed at the Centers for Disease Control and Prevention.

Case Definition A confirmed case is a clinically compatible history with a history of sheep or goat contact and positive test for the orf virus at the Centers for Disease Control and Prevention.

Case description In July 2006, a 17-year-old female presented to her health care provider in northwest Illinois with a lesion of three weeks duration on the tip of her right middle finger. The provider lanced the lesion and recovered a small amount of blood, sutured it, placed the patient on and referred her to a dermatologist. The patient presented to the dermatologist the next day. The lesion was 1.3 cm in diameter and had a red center with a white ring and red halo. Due to the appearance of the lesion the dermatologist suspected orf virus infection. A biopsy of the lesion was sent to the CDC for laboratory confirmation. An immunohistochemical (IHC) test using an immunoalkaline phosphatase technique was negative. Real-time PCR was performed and was positive for pox virus. The patient had been bottle feeding lambs three weeks prior to the appearance of the lesion. She admitted to letting the lambs nurse on her fingers. The lambs had not been vaccinated against orf. The lesion resolved within one month of the initial presentation.

128 Pertussis

Background Pertussis is a highly infectious and is caused by and is characterized by a paroxysmal cough that can last several weeks. Pertussis should be considered in adolescents and adults especially if the cough is associated with vomiting or gagging or persists more than two weeks. Pertussis in adults may be missed because symptoms may be atypical, and nasopharyngeal cultures are rarely positive if taken during the first seven days of illness. Pertussis is transmitted from person to person via aerosolized droplets from cough or sneeze or by direct contact with secretions from the respiratory tract of infectious persons. Pertussis can be highly infectious during the three weeks after onset of illness. The incubation period is usually seven to 10 days although it can range from six to 20 days. A resurgence of cases has been reported in the last decade in the United States. A total of 15,632 pertussis cases (5 per 100,000) were reported to CDC from states in 2005. The likely explanation for the increase are increased circulation of B. pertussis, waning vaccine-induced immunity among adolescents and adults, increased reporting and increased use of PCR testing. Of these cases, the incidence was highest (84 per 100,000 population) in infants younger than 6 months of age (too young to have received three doses of vaccine). Adolescents and adults account for the majority of cases. Vaccine-induced immunity wanes about five to 10 years after pertussis vaccination. For the first week, mild fever, coryza and cough are common. From week one through six, a paroxysmal cough, inspiratory whoop, and post-tussive vomiting may occur. From six to 12 weeks, the intensity of cough decreases. Outbreaks are managed through prompt treatment of patients and antimicrobial prophylaxis of close contacts. Acellular pertussis vaccines are used in children from 6 weeks to 6 years of age. Pertussis has increased in adults. Active immunization with five doses of vaccine at 2, 4, and 6 months of age, at 12 to 15 months and at school entry can prevent this disease. However, immunity from childhood vaccination decreases beginning five to 15 years after the last dose. Vaccination with Tdap vaccine of persons aged 11 to 64 is recommended. In the national immunization survey, vaccine coverage rates for greater than or equal to 4 doses of DTaP among children 19 to 35 months of age in Illinois was 84 percent as compared to 85 percent nationally in 2006. To confirm the diagnosis of pertussis in symptomatic adults, physicians should obtain a nasopharyngeal aspirate or swab for B. pertussis culture within two weeks of cough onset. The lack of fast, sensitive and specific tests makes laboratory diagnosis difficult. PCR was introduced in 1997. In outbreak settings, positive PCR should be interpreted in conjunction with epidemiologic investigation, clinical course and confirmed by culture. A subset of cases should be cultured. Culture is the standard and 100 percent specific. Its sensitivity can be up to 56 percent early in the course of illness but decreases with delays in specimen collection, in vaccinated patients or patients treated with antimicrobials. Isolation of the organism can take seven to 14 days.

129

Case definition The case definition for pertussis in Illinois is a clinically compatible illness that is laboratory confirmed or epidemiologically linked to a laboratory-confirmed case. Laboratory confirmation is through culture of B. pertussis from a clinical specimen. A clinically compatible illness is a cough lasting at least two weeks with one of the following: paroxysms of coughing, inspiratory whoop or post-tussive vomiting (without other apparent causes) or greater than two weeks of cough in a person in an outbreak setting. A confirmed case is defined as a cough illness of any duration in any person with isolation of B. pertussis or a case that meets the clinical case definition and is confirmed by polymerase chain reaction or by epidemiologic linkage to a laboratory- confirmed case. A probable case meets the clinical case definition but is not laboratory confirmed or epidemiologically linked to a laboratory-confirmed case.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - 588 (five-year median = 321) (Figure 74). There were 358 confirmed and 230 probable cases reported. The one-year incidence rate for pertussis was 4.7 per 100,000. • Age - Eighteen percent occurred in those younger than 5 years of age (Figure 75). In 2006, 32 percent of cases occurred in those older than 19 years of age. • Gender - Females comprised 56 percent of cases. • Race/ethnicity - Ninety percent were white, 6 percent were African American, 3 percent were in other races. Seventy-four cases were of unknown race; Twelve percent reported Hispanic ethnicity. • Seasonal variation - Cases increased from August to January (Figure 76). • Outbreaks – There were four specific outbreaks reported in INEDSS including one in Jo Daviess County, one in McLean County, one in a Chicago school and one in a Cook County school. An overall increase occurred in the state.

Summary The number of yearly reported pertussis cases decreased since 2005 in Illinois but was higher than the five-year median. The highest incidence occurred in those younger than 1 year of age. There were 588 pertussis cases reported in Illinois in 2006 including four outbreaks in three counties involving 75 persons (13 percent of the total reported cases).

Suggested readings Counard, C. et. al. Use of mass Tdap vaccination to control an outbreak of pertussis in a high school-Cook County, Illinois. September 2006-January 2007. MMWR 2008;S7(29):796-99. Kirkland, K.B. et al. Outbreaks of respiratory illness mistakenly attributed to pertussis- New Hampshire, Massachusetts, and Tennessee, 2004-2006. MMWR 2007;56(33):837-842.

130 Wooten, K.G. et al. National, state and local area vaccination coverage among children aged 19-35 months-United States, 2006. MMWR 2007;56(34):880-85.

Figure 74. Pertussis Cases in Illinois, 2001-2006

2000 1554 1500 922 1000 588 321 500 194 231

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 75. Age Distribution of Pertussis Cases in Illinois, 2006

40 30 20 10 0 Incidence of cases <1 yr 1-4 yr 5-9 yr 10-19 yr >19 years Year

Figure 76. Pertussis Cases in Illinois by Month, 2006

100 80 60 40 20

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

131 Background Q fever is an acute rickettsial disease. Coxiella burnetti is the causative agent. Q fever is a worldwide zoonosis. Phase I is found in nature and phase II after multiple laboratory passages in the laboratory. The infective dose can be very low, as low as one organism. The diagnosis of Q fever relies on serologic testing. In 60 percent of cases, acute Q fever can be asymptomatic. In patients with symptoms, it is usually mild and sometimes complicated by febrile illness, pneumonia or hepatitis infection. Chronic Q fever may appear as . Persons at higher risk of infection include animal workers. The animal reservoirs include sheep, cattle, goats, cats, dogs, and some wild animals. The organism can be shed in high quantities in placental fluids at parturition. Ticks can be a rare source of infection in the United States. Q fever is most commonly transmitted through airborne dissemination of the organism in dust from premises contaminated with placental tissues and excreta of infected animals, in necropsy rooms or in animal processing establishments. Rarely, it can be transmitted from consumption of unpasteurized milk or cheese. The incubation period is from two to three weeks. Q fever is also a Category B bioterrorism agent. Outbreaks have been linked to aerosol transmission in heavy winds. In 2006, 169 cases of Q fever were reported to CDC.

Case definition

A confirmed case of Q fever is a clinically compatible illness with either isolation of C. burnetti from a clinical specimen, demonstration of C. burnetti in a clinical specimen by detection of antigen or nucleic acid, or a fourfold or greater change in serum antibody titer to C. burnetti antigen. A probable case is defined as a clinically compatible or epidemiologically linked case with an elevated serum antibody titer to C. burnetti.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 17 cases were reported. One was confirmed. • Age - Cases ranged in age from 14 to 74 (mean = 45 years-of-age) • Gender - Females comprised 41 percent of cases. • Race/ethnicity – Sixty-nine percent were white, 8 percent were African American, and 23 percent were other races. Four cases had unknown race; 15 percent reported Hispanic ethnicity. • Seasonal variation - Cases reported onsets from January through December. (Figure 78). • Hospitalization – Seven of 12 cases (58 percent) were hospitalized. No fatalities were reported. • Reporting - Forty-one percent of cases were reported by laboratories. • Geographic location – Twelve counties reported cases. Counties reporting multiple cases included Stephenson (three), Rock Island (two), Pike (two) and

132 Kane (two). • Risk factors – Five cases reported exposure to cattle, sheep or goats. No cases reported consuming unpasteurized dairy products.

Summary Seventeen cases of Q fever were reported in 12 Illinois Counties. Only five reported a history consistent with exposure to cattle, sheep or goats.

133 Rabies

Background In the United States, rabies is a disease that affects primarily wildlife populations. It is a neurologic illness that follows infection with a rhabdovirus. It produces encephalitis and typically progresses to death. Transmission of rabies to humans results from the bite of a rabid animal or from contact between the saliva of a rabid animal and a or wound. The rabies virus is inactivated by sunlight, heat and desiccation. The incubation period is usually three to eight weeks. Symptoms may include fever, anxiety, malaise, and tingling and pruritus at the bite site. Neurologic signs, beginning two to 10 days later, may include hyperactivity, paralysis, agitation, confusion, hypersalivation and convulsions. The paralytic form of rabies must be differentiated from Guillain Barré syndrome. After two to 12 days, the patient may go into a coma and experience respiratory failure. Rabies should be considered in the differential diagnosis of any acute rapidly progressive encephalitis, regardless of documentation of an animal bite. In 2006, the United States and Puerto Rico reported three cases of human rabies and 6,940 cases of animal rabies. Wild animals accounted for 92 percent of the animal cases reported in the United States; the top three species with rabies were the raccoon, bat and skunk. The top six rabies-positive bats after speciation (not done in all states) were the big brown bat (64 percent), Mexican free-tailed bat (9 percent), little brown bat (8 percent), Western pipistrelle (4 percent), red bat (4 percent) and hoary bat (3 percent). The most commonly identified rabid bat in the United States was the big brown bat. The peak of bat rabies in the United States occurs in August. Rabies virus transmission among bats is mainly intraspecific. In a study of bats submitted for rabies testing in Minnesota in 2003, rabid bats were more likely than non-rabid bats to be found in September, found outside, found in a wooded area, unable to fly, acting ill, or acting aggressively. Rabid bats were not more likely to be found during the day or to have bitten someone. Three human cases of rabies occurred in the United States in 2006. The cases were residents of Texas, Indiana and California. The Texas and Indiana cases were linked to bat exposures. The California case was in a patient who had been bitten by a dog while living in the Philippines. From 1990 to 2006, 51 human rabies cases were reported in the United States and Puerto Rico. Thirty-seven of 40 (92 percent) were infected with rabies variants associated with bats. Over the past 40 years in Illinois, the skunk and bat have been the main wildlife reservoirs of rabies virus. The last human case of rabies in Illinois was reported in 1954.

Case definition The case definition for human rabies is a clinically compatible illness that is laboratory confirmed. Laboratory confirmation is through detection by direct fluorescent antibody of viral antigens in a clinical specimen (preferably brain tissue or punch biopsy of the nape of neck, including at least 10 hair follicles where associated nerves are likely

133 to show evidence of infection), or isolation of rabies virus from saliva or cerebrospinal fluid (CSF), or identification of a rabies-neutralizing titer of greater than 1:5 in the serum or CSF of an unvaccinated person. A case of animal rabies is confirmed by DFA of brain tissue. If samples are sent to CDC, as is normally done only for confirmation of a positive result in a domestic species, the CDC results are used as the final results for the purposes of this report.

Descriptive epidemiology Number of animals submitted for rabies testing in Illinois in 2006 – 4,515; 59 additional heads did not meet criteria established by the testing laboratories (Illinois Departments of Agriculture and Public Health). Examples of unsatisfactory specimens are those determined to be too decomposed or too damaged to test. Forty-six specimens were DFA positive; all were bats (Table 5). Trends in animal rabies testing in Illinois are shown in Figure 77.

• Rabies positivity rate - Table 6 shows the rabies positivity rate in different species of animals in Illinois from 1971 to 2006. This information can be useful in explaining why rabies PEP is not recommended for the large majority of mouse, rat and squirrel bites. No rats, mice or squirrels have been identified with rabies in Illinois in more than 30 years. Because bats with rabies are identified almost every year in Illinois, rabies PEP is recommended for exposures to these animals and many other wild mammals unless they can be tested and are negative for rabies. When comparing the positivity rates for cumulative 1971-2006 data vs. 1991-2006 data, the percentage of skunks positive for rabies declined dramatically, and the percentage of positive bats stayed very constant. • Exposures to rabid bats - There were 46 rabid bat situations. o In 35 of the 46 rabid bat situations, no human exposures sufficient to require rabies PEP (per ACIP guidelines) occurred (for three situations, the human exposure information was unknown at the time of this report). In 16 situations, bats were found inside homes. In 19 situations the bat was found alive outside in yards, pools or near barns, and in 11 situations the location of where the bat was found was unknown. o Domestic animals (all dogs or cats) were either exposed or possibly exposed in 17 situations (Table 7). • Testing of bats - Bats accounted for all of the confirmed rabid animals in 2006. The total number of bats tested for rabies was 1,311 (positivity rate = 3.5 percent). o Geographic distribution - Rabid bats were dispersed in 20 counties across the state (Figure 78). The following counties had rabid bats: Bureau (one), Champaign (four), Cook (five), DeKalb (one), DuPage (two), Edwards (one), Fulton (one), Jackson (one), Kane (one), Lake (three), McHenry (two), McLean (two), Massac (one), Ogle (one), Piatt (one), Sangamon (five), Vermilion (three), Will (four), Williamson (two) and Winnebago (five). . Speciation - The Illinois Natural History Survey speciates bats tested for rabies in Illinois. In 2006, 1,246 bats tested for rabies

134 were speciated. Forty-six positive bats were speciated including the big brown bat (32), eastern red bat (six), hoary bat (three), eastern pipistrelle (three), silver-haired bat (one) and little brown bat (one). Of the 1,200 negative bats speciated, the following results were found: big brown bat (891), silver-haired bat (144), little brown bat (28), northern long-eared bat (19), hoary bat (eight), eastern pipistrelle (seven), evening bat (five), Indiana bat (one), Mexican free-tailed bat (one) and Myotis sp, not further identified (five). o Seasonal variation - Figure 79 shows bats submitted for testing by month in 2006. Bats submitted for rabies testing increase in August and September.

• Testing of skunks - Rabies testing was performed on 125 skunks in 2006 as compared to 216 in 2005. At least one skunk from each of 27 Illinois counties was tested; no skunks were tested in 75 counties. The following counties submitted more than five skunks for rabies testing: DuPage (28 skunks tested), Cook (16), Lake (14), McHenry (12), McLean (12) and Will (12). For rabies surveillance to be optimal in Illinois an adequate number of skunks, the main terrestrial animal reservoir, must be tested. Test results from wild terrestrial mammals is one factor used to determine whether rabies PEP is recommended in cases of stray dog and cat bites. If enough skunks from throughout the state are not tested, recommendations against rabies PEP following such a bite cannot be made with confidence.

Figure 80 shows the number of rabid skunks found in Illinois and the road kill index from 1975 through 2006. The road kill index is calculated by the Illinois Department of Natural Resources as a measure of changes in the skunk population size. When the road kill index increases, the skunk population is increasing, and conditions are likely to be suitable for a rabies epizootic in skunks. This last occurred in the late 1970s and early 1980s, when the road kill index and the rate of skunks testing positive for rabies both increased.

Summary Bats were the main species identified with rabies in Illinois in 2006. Illinois was one of six states reporting rabies in bats but not in terrestrial animals. Testing of skunks for rabies has declined in Illinois, thereby decreasing the reliability of surveillance of the terrestrial animal reservoir in the state. Local animal control jurisdictions are encouraged to increase submission of skunks for rabies testing to maintain surveillance in this species.

Suggested readings Liesener, A.L., et al. Circumstances of bat encounters and knowledge of rabies among Minnesota residents submitting bats for rabies testing. Vector-borne and Zoonotic Disease 2006; 6(2): 208-215.

135

Table 5. Animal rabies testing in Illinois in 2006

Species Total number suitable Total for testing positive % positive

Bat 1,311 46 3.5

Cat 952 0 0

Cattle/buffalo 111 0 0

Dog 1,573 0 0

Coyote/fox/wolf 21 0 0

Ferret 6 0 0

Horse/donkey 29 0 0 Opossum 31 0 0

Raccoon 156 0 0

Rodents/lagomorphs 167 0 0

Sheep/goats 11 0 0

Skunk 125 0 0

Other* 22 0 0

TOTAL 4,574 46 N/A *”Other” species tested in 2006 included alpaca, deer, kangaroo, lion and llama. Source: Illinois Department of Public Health

136 Figure 77. Trends in Animal Rabies Testing in Illinois, 1990-2006

1500 1000 # skunks tested 500 # bats tested

Number of of Number 0 animals tested

1990 1992 1994 1996 1998 2000 2002 2004 2006 Year

Table 6. Rabies Positivity Rate by Animal Species in Illinois, Selected Time Spans

1971-2006 1991-2006

Species # tested # positive % positive # tested # positive % positive

Bat 14,895 692 4.6 9,722 390 4.9 Cat 45,584 141 0.3 18,586 4 0.02 Cattle 3,919 215 5.5 1,487 4 0.27 Dog 47,964 110 0.2 24,419 5 0.02 Fox 1,452 73 5.0 267 1 0.37 Horse 762 23 3.0 305 1 0.3 Mouse 4,749 0 0 704 0 0 Raccoon 9,903 17 0.2 3,621 0 0 Rat 1,885 0 0 375 0 0 Skunk 7,829 2,532 32 1,661 50 3.0 Squirrel 7,128 0 0 1,966 0 0

Source: Illinois Department of Public Health

137 Table 7. Type of Exposure to Rabid Bats by Month, Illinois, 2006

County Animal Date Human exposure? exposure? January DeKalb None; picked up with pliers 11 dogs and cats April Ogle None, one bat in home; 2 family None members decided to get treatment anyway May DuPage None, five family members One vaccinated decided to get PEP anyway dog May McHenry None None May Winnebago None Cat May Winnebago One person woke up to bat in None room; three household members received rabies PEP May Sangamon None, but child received treatment None June Will Unknown Unknown June Williamson None Cat June Will One person bitten Unknown July Edwards None None July Fulton None Unknown July Vermilion None, but four persons received Unvaccinated rabies PEP dog July Piatt One person bitten and received Unknown rabies PEP July Cook (Chicago) None None July Vermilion None None August Williamson None Unvaccinated puppy had to be euthanized August Sangamon None; One received PEP after Unvaccinated picking up bat with towel puppy August Champaign None; Bat in home; three None household members received rabies PEP August Lake Three persons received PEP;bat None swooping at head August Cook None None August Massac None Two vaccinated dogs August McHenry None, two persons received PEP None August Lake One person Unknown 138 August Cook (Chicago) Six persons received PEP Two unvaccinated cats August Winnebago Unknown Vaccinated cat August Will None Vaccinated dog August Lake None None August Champaign One person exposed, two others Two vaccinated also received PEP dogs August Winnebago Unknown Unknown August Will None None August Sangamon One person received PEP Cat August Sangamon None, but three persons received Dog PEP August McLean One child left alone with bat; three None persons received PEP August DuPage None None August Jackson None None August Cook None None September Kane One animal control officer had Two bare handed contact; three unvaccinated household members received PEP cats euthanized with bat in home and one vaccinated dog September Winnebago Two received PEP None September Bureau None Two unvaccinated cats confined September Vermilion None None September Champaign None None September Champaign None None October Sangamon None None October Cook (Chicago) None None October McLean None Vaccinated dog

Source: Illinois Department of Public Health

139

Figure 78. Geographic Distribution of Rabid Animals in Illinois, 2006

Jo Daviess Stephenson Winnebago McHenry Lake 0 Boone 0 5 0 2 3

Carroll Ogle 0 1 Kane DeKalb 1 DuPage 1 Cook 2 5 Whiteside Lee 0 0 Kendall 0 Will Rock Island Bureau 4 Henry 0 1 La Salle 0 0 Grundy Mercer Putnam 0 0 0 Kankakee Stark 0 0 Marshall Knox 0 0 Livingston Henderson Warren Woodford 0 Peoria 0 0 0 Iroquois 0 0

Tazewell McLean Ford McDonough Fulton 0 Hancock 2 0 0 1 0 Mason Schuyler Vermilion 0 De Witt Champaign 0 Logan 0 3 0 4 Menard Piatt Adams Brown Cass 0 1 0 0 0 Macon Sangamon 0 Douglas Morgan 5 0 Edgar Pike Scott 0 Moultrie 0 0 0 0 Christian Coles 0 0 Shelby Greene 0 Clark 0 Macoupin Cumberland 0 0 Calhoun 0 Montgomery 0 0 Jersey Effingham 0 Fayette 0 Jasper Crawford 0 0 0 Bond Madison 0 0 Clay Lawrence 0 Richland 0 Marion Clinton 0 0 0 St. Clair Wayne Wabash 0 0 Washington 0 Edwards 0 Jefferson Monroe 1 0 0 White Randolph Perry Hamilton 0 0 0 Franklin 0 0

Jackson Saline Gallatin 1 Williamson 2 0 0

Hardin Union Johnson 0 0 0 Pope 0 Pulaski Massac Alexander 0 1 0

140

Table 8. Bat speciation results from bats submitted for rabies testing in 2006

Species Common Name # testing neg. # testing pos. # unsatisfactory Eptesicus Big brown bat 913 32 21 fuscus Lasiurus Red bat 93 6 6 borealis Lasiurus Hoary bat 8 3 0 cinereus Lasionycteris Silver-haired bat 152 1 0 noctivagans Pipistrellus Eastern 7 3 0 subflavus pipistrelle Myotis Little brown bat 28 1 0 lucifugus Myotis Northern long- 20 0 1 septentrionalis eared bat Nycticeius Evening bat 5 0 0 humeralis Myotis sodalist Indiana bat 1 0 0 Myotis spp 5 0 0 Tadarida Mexican free- 1 0 0 brasiliensis tailed bat Unknown 2 0 3 TOTAL 1,235 46 31 Source: Illinois Natural History Survey

Figure 79. Bat Testing for Rabies by Month, 2006

500 400 300 200 tested 100

Number of bats bats of Number 0 Jan Feb Mar Apr May June Jul Aug Sep Oct Nov Dec Month of testing

141 Figure 80. Skunk Rabies and Skunk Road Kill Index in Illinois, 1975-2006

600 6 400 4 200 2 Number of Road kill index kill Road rabid skunks rabid 0 0 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 Year

Rabid skunk Road kill index

142 Rabies, Potential Human Exposure

Background Exposures to animals, especially those involving bites or bat exposures, often result in the need for public health consultation on whether rabies post-exposure prophylaxis (PEP) is needed for the exposed individual. All animal bites in Illinois are reportable to local animal control for the purposes of following up with the owner of the biting animal. Animal control authorities are responsible for ensuring that dangerous animals are maintained so that they cannot injure the public. Potential human rabies exposures are reportable to human health including all instances when rabies post-exposure prophylaxis is initiated and all exposures to bats. In France a study of rabies PEP was conducted using data from 1999 to 2001. The incidence of rabies PEP was 16 per 100,000. Dogs accounted for 81 percent of situations resulting in PEP. The time between the injury and consultation was 2.6 days. Animals were available for observations for one-third of cases.

Case definition The definition of exposed person to be reported is: 1) Any contact (bite or non-bite) with a bat, or 2) Any contact (bite or non-bite) with an animal that subsequently tests positive for rabies virus infection, or 3) Anyone who was started on rabies post-exposure prophylaxis, or 4) Exposure to saliva from a bite, or contact of any abrasion or membrane with brain tissue or cerebrospinal fluid of any suspect rabid animal. Exposure to healthy rabbits, small rodents, indoor-only pets or rabies-vaccinated dogs, cats or ferrets is excluded, unless the exposure complies with subsections (a)(1) through (a)(3) above, or the animal displays signs consistent with rabies.

Descriptive epidemiology The following information was obtained from Illinois National Electronic Disease Surveillance System and investigation forms obtained during the surveillance of rabies, potential human exposures (RPHE) in Illinois during 2006. The investigation forms had questions on demographics, exposure characteristics and rabies post-exposure treatment information. Not all local health jurisdictions have submitted investigation

143 forms so this is a minimum estimate of the number of potential human rabies exposures in Illinois.

• Number of cases reported in Illinois in 2006 - There were 314 potential human rabies exposures reported. Note: Seven persons receiving rabies PEP after exposure to rabid bats were inadvertently excluded from the 314 exposed persons. The following information is based on the 314 potential human rabies exposures. • Age – Ages ranged from younger than 1 year of age to 94 years of age. The mean age of those exposed was 34 years. • Gender – Fifty-one percent of RPHE reports were in males. • Seasonal peak – Higher numbers of exposures occurred in the summer months of May through August. • Geographic location – Forty-one counties reported at least one RPHE. Fifty- seven percent of exposures took place in urban settings.

Type of exposure Three types of exposures can be summarized from the reports: bite, non-bite (scratch or abrasion or contamination of open cuts with saliva or nervous tissue, bat present in room with sleeping person or physical contact with a bat where a bite cannot be ruled out) or non-exposure (petting, handling, blood contact, bat in room but no physical contact and no one asleep). Of the 314 total exposures reported, 115 (37 percent) were due to animal bites, 136 (44 percent) from non-bite exposures and 61 (20 percent) no human exposure meeting ACIP guidelines for rabies PEP. Of the 98 bite exposures with the site of bite reported, most bites were to the arm or hand, 73 (74 percent), followed by leg or foot, 19 (19 percent), head or neck, three (3 percent) and torso, three (3 percent). The bite site was not indicated for 17 bite exposures. Of the 131 non-bite exposures due to bats, bats were found in the room with a sleeping person in 92 (71 percent) of exposures, physical contact with a bat took place in 27 (21 percent) of exposures, a child or adult with dementia was unobserved with a bat in four (3 percent) and bat was in a house in seven (6 percent). Bats were tested in 32 of the non-bite bat situations. Nineteen bats tested negative, seven tested positive and six specimens were unsuitable for testing. The other non-bite exposures included exposure to saliva from a possibly rabid wild animal (three), rabid horse saliva (one) and sharps injury while cutting into brain tissue (one).

Animals causing exposure The following information is by each individual person’s exposure history. Multiple individuals may have been exposed to a single animal. Of 314 animals causing exposures, 258 (83 percent) were wild, not domesticated animals. The types of animals causing exposures included bat, 223 (71 percent); cat, 27 (9 percent); dog, 25 (8 percent); raccoon, 23 (7 percent) and other, 13 (4 percent). The type of animal was unknown for three exposure situations. Of the 52 domestic animals exposing persons, 33 (73 percent) were described as stray and 12 (27 percent) were owned. Of the dogs 144 that exposed an individual, 13 (62 percent) of these animals had an unknown vaccination history, five (24 percent) were not rabies vaccinated and three (14 percent) were previously vaccinated but not up-to-date on rabies . None of eight owned dogs causing exposures were known to be up-to-date on their rabies vaccinations. Rabies vaccination of dogs is required in Illinois. Of the 27 cats that exposed an individual, 16 (76 percent) of these animals had an unknown vaccination history and four (19 percent) were not rabies vaccinated. One cat was up-to-date on rabies vaccination. Thirty-one (79 percent) of bites from dogs and cats were provoked. For domestic animal exposures, 40 (82 percent) were unavailable for either confinement or testing, four (8 percent) were tested for rabies and five (10 percent) were confined for observation. Four (9 percent) of the owned domestic animals were owned by the family of the person bitten and eight (18 percent) were owned by another individual. There were 186 (73 percent) of wild animals that were not available for confinement or testing. Sixty-nine (27 percent) of animals potentially exposing someone to rabies were submitted for rabies testing. Of the 69 wild animals submitted for rabies testing, 31 (45 percent) were negative, 28 (41 percent) were rabies positive and 10 (14 percent) were unsuitable for testing. Twenty-eight people were exposed to rabid bats. Note: An additional 21 person received rabies PEP after rabid bat exposures but were not entered into this database. The specimens that were unsuitable for testing were from nine bats and one skunk. In 10 exposures, the exposing animal was reported to exhibit signs of rabies. Signs of rabies included aggression, five (50 percent); no fear of humans, one (10 percent); other, two (20 percent) and multiple, two (20 percent).

Rabies post-exposure prophylaxis (PEP) During 2006, 262 persons were reported to have started rabies PEP. The first recommendation about whether rabies PEP was needed for a person starting rabies PEP came from the following sources: public health personnel, 92 (37 percent), health care provider, 149 (61 percent) and other, five (2 percent). The final recommendation on rabies PEP for those starting rabies PEP came from public health personnel, 98 (40 percent) and health care provider, 142 (58 percent). For 16 exposed persons receiving PEP, the source of the final recommendation was not known. For 137 (69 percent) of persons with information available, rabies PEP was completed in an emergency department followed by completion in a physician’s office, 52 (26 percent). Most rabies PEP was paid for by private insurance, 115 (77 percent), followed by Medicare or Medicaid, 16 (11 percent), no payment source, eight (5 percent), worker’s compensation, two (1 percent) and out-of-pocket expense, eight (5 percent). Payment source was unknown for 113 persons. Seventeen (6 percent) of persons recommended for rabies PEP refused to be treated. None developed rabies. Rabies PEP was completed in 217 (83 percent) of 261 persons for whom information was available. In 25 persons, rabies PEP was not completed. In 10 persons rabies PEP was not completed because the animal was tested negative. Of these 10 situations, six were bat exposures, three were raccoon exposures, and one was a dog

145 exposure. The rabies PEP recommendation for these 10 persons was made mainly by health care providers (seven situations). In five (21 percent) of situations, the animal was a low-risk species, in seven (29 percent) of situations the patient refused to complete treatment, in one situation the person was lost to follow-up, one person had other reasons and the reason was unknown for one person. Decisions on rabies PEP should be based on the Advisory Committee on Immunization Practices (ACIP) guidelines. For 298 exposed persons, it was possible to determine if the PEP recommendation followed ACIP guidelines. For 181 (61 percent) of these persons, rabies PEP was recommended and the recommendation followed ACIP guidelines. For 95 (32 percent) of persons, rabies PEP was recommended but this was not correct according to ACIP guidelines. For 22 persons (7 percent), rabies PEP was not recommended and that was correct according to ACIP. There were no persons for whom PEP was not recommended and that was an incorrect recommendation. In 95 situations, PEP was recommended incorrectly. In 46 situations, PEP was recommended when a bat was found in a house, even though no one was sleeping in the room. The ACIP recommends rabies PEP if the bat is found in a room with a sleeping person or person who is unable to say whether they were bitten. In 12 situations an animal that exposed someone tested negative for rabies but PEP was started. Because the turnaround time is rapid for rabies testing, PEP can be delayed until the testing of the animal takes place. Because of the lack of terrestrial animal rabies in the last few years in Illinois, no rabies PEP would be recommended if the dog or cat bite was provoked and the animal showed no signs of rabies. In 26 situations, persons were recommended for PEP even though a domestic animal exposed the person with a provoked bite and was not acting abnormally. In four situations a low risk animal, rodent or opossum, bit someone and PEP was recommended. In seven situations persons who were not exposed to saliva or neurologic tissue were incorrectly recommended for rabies PEP. Of the persons exposed, 217 completed rabies PEP. For 45 of 161 (28 percent) persons completing rabies PEP and with information available, the ACIP rabies protocol was followed exactly. One hundred nineteen people had incorrect administration of rabies PEP. Types of incorrect administration were incorrect timing of injections (77, 66 percent), multiple problems (16, 14 percent), no RIG given (eight, 7 percent), incorrect site of administration of injections (16, 14 percent) and two unknown. Twelve persons started on rabies PEP had been pre-exposure immunized for rabies.

Summary There is vast underreporting of potential human rabies exposures in Illinois with some jurisdictions not reporting any exposures. Therefore, the summary information is not a complete picture of human rabies exposures in Illinois. Thirty-seven percent of reported exposures were due to bites. Most bites were to the hand or arm which is typical as persons reach to pick up or handle an unfamiliar animal. Of the non-bite exposures, 71 percent of reported exposures were from bats found in a room with a sleeping person. Education of the public and animal control personnel could result in increased submission of bats that have exposed person in homes being tested for rabies. If the bat tests negative, the person would not need rabies PEP.

146 The main animal causing potential human rabies exposures was the bat, followed by the cat, dog and raccoon. This is primarily due to the definition of possible rabies exposure to a bat. The bat is the only wild mammal where rabies PEP is recommended if a person is in a room sleeping where a bat is found and it cannot be tested, or tests positive. Fifty-eight percent of final rabies PEP recommendations were made by emergency department health care providers or other health care providers. This indicates the importance of providing health care providers with up-to-date information on rabies incidence in their area and on rabies PEP recommendations. Thirty-two percent of rabies PEP given in 2006 would not have been indicated according to public health guidelines. In some situations persons were started on rabies PEP even though the animal was available for testing. Health care providers, especially in emergency departments, should be advised that rabies testing of animals can be completed rapidly at the state laboratories, and, if necessary, emergency testing can be requested for high priority specimens on holidays or weekends. For emergency testing, health care providers can contact local health department personnel or use the state emergency phone number. Rabies PEP can be delayed until testing is completed if testing is prompt. The rabies PEP protocol is provided in, “Human Rabies Prevention-United States, 1999. Recommendations of the Advisory Committee on Immunization Practices (ACIP): MMWR 1999;48(RR-1)”. In 28 percent of cases where rabies PEP was completed, PEP was administered correctly. Common errors in administration included incorrect timing of injections and forgetting to administer RIG. The ACIP recommendation for rabies PEP should be adhered to when administering rabies PEP. It can be difficult to get exposed individuals to adhere to a complicated vaccination schedule but the person should be informed about the universally fatal nature of rabies and the importance of adhering to the ACIP schedule.

Suggested readings Gautret, P. et. al. Rabies post exposure prophylaxis, Marseille, France, 1994- 2005. EID (serial on the Internet) 2008. Sep. Avail from http://www.cdc.gov/EID/content/14/9/1452.htm.

147 Rocky Mountain Spotted Fever

Background Rocky Mountain spotted fever (RMSF) is the most frequently reported fatal tick- borne disease in the United States. RMSF has been reported throughout the continental United States. The causative agent is rickettsii. Both dogs and humans may experience clinical illness due to RMSF. In 2006, 2,288 human cases were reported nationally to the CDC. Most cases are reported from April through September when the greatest number of Dermacentor ticks are present in the environment. The ticks that are most likely to transmit RMSF include the American dog tick (Dermacentor variabilis) in the central United States. Only about 1 percent to 5 percent of ticks usually are infected with R. rickettsii in an area where transmission to humans occurs. In order for one of these ticks to transmit the bacteria, it must be attached for at least four to six hours. A history of a tick bite can be elicited in approximately 60 percent of RMSF cases. The incubation period for RMSF is three to 14 days after a tick bite. Common presenting symptoms include high fever, severe headache, deep myalgias, fatigue, chills and rashes. A rash typically appears within two to four days after onset of fever. The rash typically begins on the ankles, wrists or forearms. A rash can be atypical or absent in up to 20 percent of RMSF cases. Starting most often on the ankles and wrists, the rash then appears on the trunk, palms and soles. Patients also may have gastrointestinal signs such as abdominal pain and nausea which may be serious enough to lead to an erroneous diagnosis such as appendicitis. RMSF can have a case fatality rate of 20 percent in untreated persons, while the case fatality rate is 5 percent in treated persons.

Case definition The case definition for a confirmed case of RMSF in Illinois is a clinically compatible illness that is laboratory-confirmed. The laboratory confirmation is a four-fold or greater rise in antibody titer by immunofluorescent antibody (IFA), complement fixation (CF), latex agglutination (LA), microagglutination (MA) or indirect hemagglutination antibody (IHA) test in acute and convalescent specimens ideally taken more than three weeks apart; or demonstration of positive immunofluorescence of a skin lesion or organ tissue, positive polymerase chain reaction or isolation of R. rickettsii from a clinical specimen. A clinically compatible illness is one characterized by acute onset and fever, usually followed by myalgia, headache and petechial rash. A probable case is defined as a clinically compatible case with a single IFA serologic titer of at least 64 or a single CF titer of at least 16 or other supportive serology (four-fold rise in titer or a single titer at least 320 by Proteus OX-19 or OX-2, or a single titer at least 128 by an LA, IHA or MA test).

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – Twenty-six cases were reported and all were probable cases (five-year median = 12).

148 • Age - Cases ranged in age from six to 72 years of age (mean = 39 years). • Gender – Fifteen cases were male (58 percent). • Race/ethnicity - Seventeen cases were white, one reported other race; and nine cases had unknown race; one case was Hispanic. • Geographic distribution – The majority of the cases resided in the southern Illinois region (Figure 81). • Seasonal variation - Onsets of the cases ranged from January to November. An increase in cases occurred from May to August (19 cases). • Symptoms/outcomes – Symptoms reported by cases included fever in 23 cases (92 percent), rash in 11 cases (50 percent), headache in 19 cases (83 percent), thrombocytopenia in two cases (22 percent) and neurologic in three cases (17 percent). Eleven of 24 cases (46 percent) were hospitalized. No cases were fatal. • Reporting – The majority of cases were reported by laboratories (81 percent). • Tick exposure – Fourteen of 18 (78 percent) of cases with a tick habitat history reported being in a tick habitat. Of the 12 persons who reported the type of tick habitat, the following location types were reported: own property (four), farm (three), park or nature preserve (three) and camp (two). Nine of 18 cases (50 percent) reported a history of a tick bite. Tick exposures took place primarily in the southern region of Illinois (13 of 19 cases, or 68 percent). One case reported a Winnebago County exposure. Five cases reported out of state exposures, one each in Alabama, Missouri, Hawaii, North Carolina and Wisconsin. Seven had unknown exposure histories. • Past incidence - Rocky Mountain spotted fever cases reported per year in the state were: 1991 (five), 1992 (two), 1993 (four), 1994 (11), 1995 (10), 1996 (four), 1997 (three), 1998 (one), 1999 (seven), 2000 (five), 2001 (12), 2002 (12), 2003 (five), 2004 (14) and 2005 (11).

Summary Most cases of RMSF occurred in summer months and 68 percent reported exposures in southern Illinois. The number of cases was more than 20 over the five- year median but all cases were probable cases with single titers.

149

Figure 81. Exposure Locations for RMSF Cases With In-state Exposures, 2006

Jo Daviess Stephenson Winnebago McHenry Lake 0 Boone 0 1 0 0 0

Carroll Ogle 0 0 Kane DeKalb 0 DuPage 0 Cook 0 0 Whiteside Lee 0 0 Kendall 0 Will Rock Island Bureau 0 Henry 0 0 La Salle 0 0 Grundy Mercer Putnam 0 0 0 Kankakee Stark 0 0 Marshall Knox 0 0 Livingston Henderson Warren Woodford 0 Peoria 0 0 0 Iroquois 0 0

Tazewell McLean Ford McDonough Fulton 0 Hancock 0 0 0 0 0 Mason Schuyler Vermilion 0 De Witt Champaign 0 Logan 0 0 0 0 Menard Piatt Adams Brown Cass 0 0 0 0 0 Macon Sangamon 0 Douglas Morgan 0 0 Edgar Pike Scott 0 Moultrie 0 0 0 0 Christian Coles 0 0 Shelby Greene 0 Clark 0 Macoupin Cumberland 0 0 Calhoun 0 Montgomery 0 0 Jersey Effingham 0 Fayette 0 Jasper Crawford 0 0 0 Bond Madison 0 0 Clay Lawrence 0 Richland 0 Marion Clinton 1 2 0 St. Clair Wayne Wabash 0 0 Washington 0 Edwards 0 Jefferson Monroe 0 0 0 White Randolph Perry Hamilton 0 0 0 Franklin 0 2

Jackson Saline Gallatin 2 Williamson 1 0 1

Hardin Union Johnson 1 1 1 Pope 0 Pulaski Massac Alexander 0 0 0

150 Salmonellosis (Non-typhoidal)

Background There are more than 2,400 serovars of Salmonella. However, approximately 50 percent of human cases are caused by three serovars: Salmonella enterica ser Enteritidis, S. ser Typhimurium and S. ser Newport. Transmission to humans is usually after consumption of contaminated food products. Raw or undercooked meat, eggs, raw milk and poultry have been identified as vehicles for Salmonella infection. Fresh produce, such as lettuce, unpasteurized apple or orange juice or sprouts also have caused outbreaks. A Salmonella ser. Oranienberg outbreak associated with fruit salad was identified in the northeastern United States in persons associated with long-term care or hospital settings in 2006. During 2006, three outbreaks of Salmonella were linked to contact with baby poultry (chicks, ducklings, goslings and baby turkeys) purchased at agricultural feed stores. The three outbreaks were each traced to a single hatchery. In a study in Oregon, 18 percent of baby chicks from 10 of 16 agricultural feed stores tested positive for Salmonella. Hospital and commercial laboratories are required to submit isolates of Salmonella to the Department’s laboratory for serotyping. This is necessary to detect increases in specific serotypes. Identification of serotypes is useful in determining which patients are likely linked to a common source of infection. Another way to link Salmonella isolates to a common source is pulse field gel electrophoresis (PFGE). A new laboratory technique for subtyping isolates is multiple-locus variable-number tandem repeats analysis (MLVA) and this may prove to be useful in surveillance and outbreak investigation. This technique is currently available at CDC. Of the 10 diseases/syndromes (those caused by Campylobacter, Cryptosporidium, Cyclospora, shiga toxin producing E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites, Salmonella comprised 6,655 of 17,252 (39 percent) of the reported infections in preliminary data from 2006. The incidence rate was 14.8 per 100,000 and ranged from 11 to 20 at the 10 FoodNet sites in 2006. In preliminary data from 2006, 90 percent of isolates were serotyped. The top six serotypes were: Typhimurium (19 percent), Enteritidis (19 percent), Newport (9 percent), Heidelberg (4 percent), Javiana (5 percent), Montevideo (4 percent) and monophasic serotype I 4,[5],12:i:- (4 percent). In the United States national surveillance data, 45,808 cases of Salmonella were reported to CDC in 2006. Serotypes Typhimurium and Enteritidis were the most common. Of the nationally reported cases in six states in 2002, the median time from onset of illness to interview of patients was 14 days. The median time from onset to PFGE typing was 18 days.

Case definition The case definition for a confirmed case is isolation of Salmonella from a clinical specimen. The case definition for a probable case is a person who has a clinically compatible illness that is epidemiologically linked to a confirmed case, but is not laboratory-confirmed.

151

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 1,603 (five-year median = 1,770) (see Figure 82 for number of cases since 1997). The annual incidence rate for salmonellosis in Illinois in 2006 was 13 per 100,000 population. • Age – Salmonellosis occurred in all age groups (mean age=48) (see Figure 83). However, the incidence rate was highest in those younger than 1 year of age (67 cases per 100,000 population), followed by those in the 1 to 4 year age group (30 per 100,000). • Gender – Fifty-two percent were female. • Race/ethnicity – Seventy-six percent of cases were white, 13 percent African American and 11 percent other races; 21 percent were Hispanic. • Seasonal variation - A peak in salmonellosis cases occurred in the summer months, especially July and August (Figure 84). • Geographic distribution – For 2006, the counties with the highest incidence per 100,000 population were Massac (40), Clark (35), Gallatin (31), Cass (29), Kane (27) and Henry (27). The mean annual incidence rates for salmonellosis were highest in some scattered counties in the state (Figure 85). • Serotypes - Ninety-four percent of Illinois’ Salmonella isolates were serotyped. The most common serotypes in 2006 are found in Table 9. The four most common serotypes were S. ser. Enteritidis (309, 21 percent), S. ser.Typhimurium (303, 20 percent), S. ser. Newport (131, 9 percent) and S. ser. Heidelberg (80, 5 percent). Serotypes of Salmonella found in Illinois from 1998-2006 are shown in Table 10. The percent of infections acquired from exposures outside the United States varied by serotype (See Table 11). For 12 serotypes (Agona, Braenderup, Enteritidis, Heidelberg, Infantis, Montevideo, Muenchen, Newport, Oranienberg, Paratyphi A, Paratyphi B and Typhimurium), S. ser. Paratyphi A cases reported the highest percent of acquisition outside of the United States (91 percent). • Clinical syndrome – Cases reported diarrhea (92 percent), fever (68 percent) and vomiting (40 percent). Urinary tract infections were reported in 111 cases (60 also reported diarrhea, 44 did not report diarrhea and seven had no history of whether diarrhea was present). Of the following 12 serotypes (Agona, Braenderup, Enteritidis, Heidelberg, Infantis, Mbandaka, Montevideo, Muenchen, Newport, Oranienberg, Tennessee and Typhimurium), S. ser. Tennessee had the highest percent of isolates with urinary tract infections (100 percent), followed by Braenderup (24 percent). Thirty-five percent of Salmonella cases were admitted to the hospital. Two deaths were attributed to Salmonella. • Risk factors

Animal contact • Contact with animals was reported from 542 of 1,228 (44 percent) of cases. A history of reptile or amphibian contact was reported by 80 Salmonella cases in 2006, but a link between the reptiles and transmission of the infection was not confirmed by culture of reptiles or amphibians. . Cases reported contact with the following types of reptiles: turtles (24), 152 lizards (15), snakes (13), not specified (11) and multiple types (nine). . For those with reported reptile or amphibian contact, the mean age was 25 years; 22 cases were younger than 5 years of age. . Males accounted for 46 percent of the cases. . The two most common species in these cases were Enteritidis (19) and Typhimurium (18). Salmonella isolates from the subspecies I, II, III and IV have been associated with reptile contact and, for the 2006 reptile contact cases, the following serotypes from these groups were identified: Monschaui (one) and Telelkebir (one). Travel exposure . Of the 1,117 cases, 126 (11 percent) cases reported being in another country during their incubation period. The most common exposure destination was Mexico (50 cases), followed by India (13) and the Dominican Republic (six). There were 44 of 1,117 (4 percent) of the cases reporting travel within the United States but outside Illinois during their incubation period. The most common exposure states were Florida (six cases), Wisconsin (five cases) and Nevada (four). Swimming exposure . Eighty-eight of 1270 cases (7 percent) reported swimming in non- chlorinated water and 127 of 1234 cases (10 percent) reported swimming in chlorinated water. Residential or day care exposure . One hundred eleven of 1,294 cases (8 percent) reported contact with a residential facility, and 87 of 1,292 cases (7 percent) reported contact with a day care. . Twenty-nine cases attended a day care and six lived in a residential facility. Sensitive occupations . Sensitive occupations reported in cases included food service facility worker (32), health care worker (29), day care center (four), residential facility (three) and other sensitive occupations (17). • Reporters – Cases were reported primarily by infection control professionals (46 percent), followed by laboratory staff (44 percent) and health clinic staff (four percent). • Outbreaks - There were four confirmed foodborne outbreaks of Salmonella reported in 2006 (See the section of this report on foodborne outbreaks for more details). No person-to-person outbreaks were reported due to Salmonella.

Summary In 2006, 1,603 cases of Salmonella were reported in Illinois. The one-year incidence rate of Salmonella for 2006 was 13 per 100,000 population, which is lower than the average incidence reported at CDC’s FoodNet sites (15 per 100,000). The mean age for Salmonella cases was 48 years, although the incidence was highest in those younger than one year of age. Salmonella cases increased in Illinois during the summer which is similar to national data. The percentage of isolates that were

153 serotyped in Illinois was 94 percent, which is higher than the 90 percent of isolates serotyped in FoodNet sites. The percentages of the four most common serotypes were Typhimurium (20 percent), Enteritidis (21 percent), Newport (9 percent) and Heidelberg (5 percent). The proportions of these four serotypes was similar to the 2006 FoodNet preliminary data for those serotypes. Reptile or amphibian contact was reported in 22 cases younger than 5 years of age. CDC recommends that households with children younger than 5 years of age not have reptiles as pets.

Suggested readings Bidol, S., et al. Three outbreaks of Salmonellosis associated with baby poultry from three hatcheries. United States, 2006. MMWR 2007; 56(12):273-6. Chatfield, D., et al. Turtle-associated Salmonellosis in humans-United States, 2006-2007. MMWR 2007; 56(26):649-652. Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from http://www.cdc.gov/EID/content/14/2/311 Landry, L., et al. Salmonella Oranienberg infections associated with fruit salad served in health-care facilities – Northeastern United States and Canada, 2006. MMWR 2007; 56(39): 1025-8. Torpdahl, M. et al. Tandem repeat analysis for surveillance of human Salmonella Typhimurium infections. Emerg Inf Dis, 2007:13(3): [Serial on the Internet]. Available from http://www.cdc.gov/EID/content/13/3/388.htm.

Figure 82. Salmonella Cases in Illinois, 2001-2006

2500 1770 1955 1837 2000 1612 1603 1383 1500 1000 500

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 83. Salmonella Cases in Illinois by Age Group, 2006

80 60 40 20 0 Incidence per 100,000 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age Group

154 Figure 84. Salmonella Cases in Illinois by Month, 2006

250 200 150 100 50

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

155 Figure 85. Map of One-year Salmonellosis Incidence Rates for Illinois, 2006

Jo Daviess Stephenson Winnebago McHenry Lake Boone

Carroll Ogle Kane DeKalb DuPage Cook Whiteside Lee Kendall Will Rock Island Bureau Henry La Salle Grundy Mercer Putnam Kankakee Stark Marshall Knox Livingston Henderson Warren Woodford Peoria Iroquois

Ford McDonough Tazewell McLean Hancock Fulton

Mason Schuyler De Witt Vermilion Logan Champaign Menard Piatt Adams Brown Cass Macon Morgan Sangamon Douglas Edgar Pike Scott Moultrie Christian Coles Shelby Greene Clark Macoupin Cumberland Calhoun Montgomery Jersey Effingham Fayette Jasper Crawford Bond Madison Clay Richland Lawrence Marion Clinton St. Clair Wayne Wabash Washington Edwards Monroe Jefferson

Randolph Perry Hamilton White Franklin

Jackson Saline Gallatin Williamson

Hardin Union Pope Johnson

AlexanderPulaski Massac

156 Source: Illinois Department of Public Health

157 Table 9. Top 10 Salmonella Serotypes in Illinois, 2006.

Serotype Frequency Serotype Frequency Enteritidis 309 Muenchen 30 Typhimurium 303 Infantis 30 Newport 131 Agona 29 Heidelberg 80 Montevideo 27 Oranienberg 35 Braenderup 25

Source: Illinois Department of Public Health

Table 10. Frequency of Salmonella Serotypes in Illinois, 1998-2006 Serotype 1998 1999 2000 2001 2002 2003 2004 2005 2006 Aberdeen 0 0 1 0 0 0 0 1 0 Abony 0 0 0 0 0 0 0 0 1 Adelaide 2 3 1 4 0 6 5 9 5 Agbeny 0 0 0 0 0 0 0 0 1 Agona 129 48 27 14 20 16 22 33 29 Agoueve 0 0 0 0 0 0 0 0 1 Alachua 1 1 2 0 1 1 0 0 1 Albany 2 0 1 0 0 1 2 1 Amsterdam 0 0 0 0 0 0 0 2 1 Anatum 10 7 9 10 9 15 18 13 15 Antsalova 0 0 0 0 0 0 1 0 0 Apapa 0 0 0 0 0 0 1 0 0 Arizonae 0 1 4 2 3 1 2 2 4 Austin 0 0 1 0 0 0 0 0 0 Baildon 3 0 0 0 1 2 0 1 0 Bareilly 4 6 5 7 5 1 1 6 5 Barranquilla 0 0 0 0 0 0 0 0 2 Beaudesert 0 0 0 0 1 0 0 0 0 Berta 7 9 25 41 19 23 19 17 17 Bledgam 0 0 0 0 0 0 0 0 1 Blockley 3 4 5 1 3 2 0 2 2 Bonariensi 1 1 0 1 1 0 0 0 0 Bonn 1 0 0 0 0 0 0 0 0 Bovis-morb 11 5 7 3 2 7 3 2 5 Braenderup 32 28 18 16 21 32 79 36 25 Brandenburg 10 5 5 9 2 12 2 14 8 158 Bredeney 3 0 0 2 1 4 2 2 1 Carmel 0 0 0 0 0 0 2 0 0 Carrau 0 0 0 0 0 0 0 1 1 Cerro 0 0 1 0 0 0 2 2 0 Chailey 2 0 2 0 0 0 1 0 0 Chameleon 0 1 1 0 1 0 0 0 0 Chester 1 3 3 6 1 2 0 0 1 Cholerae-suis 3 7 4 2 1 2 2 1 1 Coeln 0 0 0 0 0 0 0 0 1 Serotype 1998 1999 2000 2001 2002 2003 2004 2005 2006 Colindale 1 0 0 2 0 0 1 0 0 Concord 0 0 0 0 0 0 0 0 1 Corvallis 0 0 0 0 0 0 0 0 1 Cotham 0 0 0 0 0 1 0 1 1 Cubana 2 0 1 2 1 0 1 0 0 Derby 13 14 14 9 14 5 10 16 16 Dublin 0 0 0 0 1 0 2 4 2 Durban 0 0 0 0 0 0 3 0 0 Durham 1 0 0 1 1 0 0 0 0 Ealing 0 1 0 0 0 0 0 0 2 Eastbourne 1 1 1 0 0 0 0 2 1 Edinburg 0 0 0 0 0 3 2 4 0 Emek 0 1 0 0 0 2 0 0 2 Enteritidis 405 264 262 246 376 207 236 325 309 Finkenwerd 0 1 0 0 0 0 0 0 0 Flint 1 2 0 1 0 0 0 0 0 Fluntern 0 0 0 0 0 0 1 0 1 Freetown 0 0 0 0 0 1 3 1 0 Gaminara 0 1 0 2 1 2 0 0 2 Give 5 4 1 1 7 2 3 5 2 Grumpensis 0 0 0 0 0 0 0 5 0 Guinea 0 0 0 0 0 1 0 0 0 Haardt 0 0 0 1 0 0 1 1 0 Hadar 40 15 26 8 16 18 16 8 19 Haifa 0 0 1 0 0 0 0 0 2 Hartford 12 16 18 15 22 9 9 9 20 Havana 1 2 2 1 2 1 4 2 1 Heidelberg 115 101 101 66 171 113 79 93 80 Herston 0 0 0 0 1 0 0 0 0 Hull 0 0 1 0 0 0 0 0 1 Hvittingfoss 2 1 3 1 4 0 2 0 1 Ibadan 0 0 0 0 0 0 0 0 2 Indiana 0 2 0 0 2 0 0 1 0 Infantis 65 51 38 35 30 130 96 35 30 Inverness 0 1 0 0 2 0 1 0 1 Irumu 0 0 0 0 0 1 0 0 0 Jangwani 0 0 0 0 1 0 0 0 0 Java 37 41 35 24 7 1 0 9 8 Javiana 11 27 24 17 19 263 24 16 11 Johannesburg 4 6 3 3 1 0 0 2 3 Kentucky 0 4 1 3 1 2 1 2 0 Kiambu 0 1 2 2 5 1 1 2 3 159 Kingabwa 0 0 0 1 0 0 0 0 0 Kintambo 0 0 0 1 0 0 0 0 1 Kottbus 0 0 0 2 0 0 1 1 0 Kua 0 0 0 1 1 0 0 0 0 Limete 0 0 0 0 0 0 0 0 1 Lindern 0 0 0 0 0 0 0 1 0 Litchfield 7 10 9 9 7 13 8 5 5 Livingstone 0 0 0 1 1 1 0 0 0 Lomalinda 0 0 2 0 9 0 0 1 0 Serotype 1998 1999 2000 2001 2002 2003 2004 2005 2006 Lomita 0 0 0 0 0 0 1 0 0 London 4 3 4 0 1 3 4 1 4 Manhattan 15 4 8 4 3 1 4 2 2 Marina 3 2 3 3 2 3 2 0 0 Matadi 0 0 0 0 0 2 0 0 0 Mbandaka 2 10 7 7 5 6 6 9 24 Meleagridis 3 0 0 0 0 2 0 1 3 Miami 3 4 2 4 2 4 1 2 1 Mikawasim 0 0 0 1 0 0 1 0 0 Minnesota 0 0 3 3 0 0 2 7 3 Mississippi 2 3 3 0 0 1 5 3 4 Molade 0 0 0 0 0 1 0 0 0 Monschaui 0 0 1 0 2 1 0 1 2 Montevideo 62 56 35 16 21 27 48 41 27 Muenchen 31 36 32 42 32 45 34 32 30 Muenster 10 1 3 2 1 1 1 5 3 Nagoya 0 0 0 0 0 1 0 1 0 Napoli 0 0 0 1 0 0 1 0 0 New-brunswick 0 1 1 0 0 0 0 0 0 Newington 2 3 0 0 0 1 0 0 0 Newport 71 59 85 121 121 151 94 68 131 Nima 1 0 1 2 1 0 0 0 0 Norwich 0 4 6 2 2 3 5 0 2 Oakland 0 0 0 0 0 1 0 0 0 Ohio 7 3 0 6 2 1 23 0 5 Onderstepoort 1 0 0 0 0 1 0 0 0 Oranienberg 26 21 24 28 37 30 26 27 33 Oranienberg var 0 0 0 0 0 0 0 0 2 14+ Orientalis 0 0 0 0 0 0 1 0 0 Orion 0 0 0 0 1 0 0 0 0 Oslo 1 5 1 1 2 2 0 1 1 Panama 3 3 2 9 11 3 5 8 11 Paratyphi a 11 1 11 2 9 18 4 7 14 Paratyphi b 1 1 1 0 1 5 18 8 11 Paratyphi c 0 0 0 1 0 0 0 2 0 Parera 0 0 0 0 0 0 1 0 0 Pensacola 0 0 0 0 0 0 1 1 0 Poano 0 1 0 0 0 1 0 0 0 Pomona 11 0 0 0 0 3 3 6 1 Poona 18 19 16 12 6 7 12 7 9 Putten 1 1 0 0 0 0 0 1 0

160 Reading 6 2 6 4 5 5 7 4 0 Richmond 0 0 0 0 1 0 0 1 1 Rissen 0 0 1 2 1 2 0 1 1 Roodepoor 1 0 0 0 0 0 0 0 0 Roterberg 1 0 0 0 0 0 0 0 0 Rubislaw 2 0 1 1 1 1 3 1 0 San-diego 1 0 3 1 5 4 11 4 9 Saint-paul 30 21 28 22 37 27 50 28 15 Saphra 0 0 0 0 1 0 0 1 0 Serotype 1998 1999 2000 2001 2002 2003 2004 2005 2006 Schwarzengrund 4 7 3 1 5 9 6 11 10 Senftenberg 8 13 9 12 8 2 1 10 4 Shubra 0 0 0 0 0 0 0 1 0 Simi 0 0 0 1 0 0 0 0 0 Singapore 0 0 2 0 0 0 1 0 1 Soahamina 0 0 0 0 0 0 0 2 0 Stanley 7 12 5 4 9 12 10 15 11 Stanleyville 0 1 0 0 0 0 0 2 0 Sundsvall 1 0 0 0 1 0 0 0 0 Takoradi 0 0 0 1 0 1 0 0 0 Tallahassee 0 0 0 0 0 0 0 0 1 Telelkebir 0 1 2 0 0 2 2 1 1 Tennessee 3 2 0 2 4 8 5 6 18 Thompson 34 30 36 24 24 30 35 33 24 Tilene 0 0 0 0 0 0 1 0 0 Typhimurium 405 354 350 285 314 373 274 376 303 Typhimurium 0 0 0 0 0 0 0 2 0 var.Copenhagen Uganda 6 5 8 15 5 3 2 2 4 Urbana 5 7 2 2 2 0 4 2 1 Utah 0 0 0 0 0 1 0 0 0 Virchow 1 8 2 4 3 11 8 4 4 Wandsworth 0 0 0 1 0 0 0 0 0 Wangata 0 0 2 1 0 0 0 0 0 Wassenaar 0 0 1 0 2 0 0 0 0 Waycross 0 0 0 0 0 2 0 0 0 Weltevreden 5 3 0 2 1 3 4 3 3 Worthington 2 1 1 0 0 15 1 0 4 I rough:d:l,w 0 0 0 0 0 0 0 0 1 I rough:e,h: 0 0 0 0 0 0 0 0 1 e,n,z,15 I rough:r:1,5 0 0 0 0 0 0 0 0 1 I rough: 0 0 0 0 0 0 0 0 1 nonmotile I 4,5,12:b:- 0 0 0 0 0 0 0 0 3 II rough:b:e,n, 0 0 0 0 0 0 0 0 1 x,z15 IIIa 0 0 0 0 0 0 0 0 1 13,22:z4z23:- Monophasic, I 0 0 0 0 0 0 0 0 1 4,12,i I 4,12,:H to 0 0 0 0 0 0 0 0 1 rough to type 161 I 4,5: nonmotile 0 0 0 0 0 0 0 0 1 Monophasic, 0 0 0 0 0 0 0 42 13 4,5,12:b Monophasic, 0 0 0 0 0 0 0 0 60 other Non-motile 0 0 0 0 0 0 0 0 3 Other 0 0 0 0 3 24 8 7 16 Too rough 0 0 0 0 0 0 0 6 1 Untyped 158 152 123 156 271 228 117 272 101 Table 11. Twelve Serotypes and Exposure Location, 2006

Serotype Exposed in Illinois Exposed in another state Exposed outside of the U.S. # % # % # % Agona 15 71 2 9 4 19 Braenderup 17 94 0 0 1 6 Enteritidis 162 72 8 4 54 24 Heidelberg 65 97 1 1 1 1 Infantis 21 100 0 0 0 0 Montevideo 19 86 1 4 2 9 Muenchen 21 87 1 4 2 8 Newport 96 96 3 3 1 1 Oranienberg 20 87 0 0 3 4 Paratyphi A 1 9 0 0 10 91 Paratyphi B 4 100 0 0 0 0 Typhimurium 182 89 8 4 13 6

162 Sexually Transmitted Diseases Included in this section are three diseases - chlamydia, gonorrhea and syphilis - transmitted primarily or exclusively through sexual contact and reportable under Illinois statutes and administrative rules. Other diseases not included in this section (such as herpes and human papilloma virus) may be transmitted sexually. HIV/AIDS is discussed in a separate section. The control of sexually transmitted diseases (STDs) is an important strategy for the prevention of HIV. The inflammation and lesions associated with STDs increase an individual’s risk for acquisition of HIV, as well as the ability to transmit HIV to others.

Chlamydia

Background infection is a significant cause of genitourinary complications, especially in women. Early symptoms of or are mild; asymptomatic infection is common in both women and men. If left untreated, chlamydia infection can lead to pelvic inflammatory disease in women. It may cause severe inflammation and damage, even though symptoms may be mild. Due to the insidious nature of the infection, C. trachomatis is a major cause of long-term sequelae such as tubal and and can cause premature rupture of membranes in pregnant women. Chlamydia also can cause ophthalmia and pneumonia in newborns exposed to it during birth. Chlamydia is reportable in all but one state. During 2006, more than one million chlamydia infections were reported to the CDC, making chlamydia the most commonly reported notifiable disease in the United States. However, national data are incomplete because the majority of testing currently is conducted in females. Federal and state funding for chlamydia is targeted at providing screening programs in STD clinics, women’s health programs (such as family planning and prenatal clinics), and in adult and juvenile correctional centers.

Case definition The case definition is isolation of C. trachomatis by culture, or demonstration of C. trachomatis in a clinical specimen by detection of antigen or nucleic acid.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 53,586; the overall incidence rate was 431 per 100,000 population. The number of cases increased by 84 percent from 1997 (9,184) to 2006 (53,586) (Figure 86). • Age - Adolescents and young adults (ages 15 to 24) accounted for 34 percent of reported chlamydia cases in 2006 (Figure 87). The average age of persons reported with chlamydia was 23. • Gender - The female-to-male ratio of reported cases was 2.9 : 1.0. • Race/ethnicity - The racial/ethnic distribution of cases was non-hispanic African American (53 percent), non-hispanic white (19 percent), non-hispanic Asian/Pacific Islander (1 percent), hispanic (10 percent) and other or unknown (17 percent). 163 • Geographic distribution - Chlamydia is geographically distributed throughout the state. Cases were reported from all 102 counties. The five counties with the highest incidence rates per 100,000 were Pope (1,360), Peoria (860), St. Clair (743), Alexander (699) and Jackson (690).

Summary Chlamydia is the most commonly reported sexually transmitted disease in Illinois. Cases were reported from all counties in Illinois during 2006. Adolescents and young adults had the highest incidence rates. Reasons for the increase in cases from 1993 to 2006 include increased testing, improved surveillance, and the use of more sensitive diagnostic tests.

Figure 86. Chlamydia Cases in Illinois, 2001-2006

53586 60000 48101 48294 50559 43716 47185 40000

20000

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 87. Age Distribution of Chlamydia Cases in Illinois, 2006

2500 2000 1500 1000 100,000 500

Incidencepepr 0 0-4 5-9 yr 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-54 55-64 65 + yr yr yr yr yr yr yr yr yr yr Year

164 Gonorrhea

Background Gonorrhea is a bacterial infection caused by . Uncomplicated urogenital infection may progress, without treatment, to complications such as infertility, pelvic inflammatory disease (PID) and disseminated infection. Resultant scarring of fallopian tubes may result in ectopic pregnancy. Women are more likely than men to suffer complications from gonorrhea infection because early symptoms are often not present or not recognized in females. Infants born to infected mothers may develop gonococcal ophthalmia, which is potentially blinding, or sepsis, arthritis or meningitis.The United States recorded 358,366 cases of gonorrhea in 2006. Currently recommended therapies for gonorrhea are highly effective, although antimicrobial drug resistance has been a problem. Gonococcal susceptibility to some currently recommended drugs is gradually declining, and active surveillance is required to monitor resistance and to ensure the effectiveness of therapy. An increase in resistance to quinolones occurred in 2006. This was the second consecutive year with an increase in cases.

Case definition Isolation of typical gram-negative, oxidase positive diplococci (presumptive Neisseria gonorrhoeae) from a clinical specimen; demonstration of N. gonorrhoeae in a clinical specimen by detection of antigen or nucleic acid; or observation of gram- negative intracellular diplococci in a urethral smear obtained from a male urethral or female endocervical smear.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 20,186; case rate was 162 per 100,000 population. Reported cases in 2006 were higher by 1 percent than the number reported in 2005 (Figure 88). Gonorrhea is the second most commonly reported STD in Illinois. • Age - Adolescents and young adults are at greatest risk for gonorrhea infection. Persons aged 15 to 24 accounted for 60 percent of reported cases in 2006 (Figure 89). The average age of cases was 25. • Gender – The ratio of reported female to male cases was 1.2: 1.0. • Race/ethnicity - Illinois minorities are disproportionately affected by gonorrhea. The reported cases were 71 percent non-Hispanic African American, 21 percent non- Hispanic white, 3 percent Hispanic and 14 percent other or unknown race. • Geographic distribution - At least one case of gonorrhea was reported in 89 Illinois counties. The five counties with the highest incidence rate in 2006 were Macon (465), Peoria (436), Sangamon (380), St. Clair (329) and Pulaski (286).

Summary Gonorrhea is the second most commonly reported sexually transmitted disease after chlamydia in Illinois. In 2006, 60 percent of gonorrhea cases in Illinois were in those 15 to 24 years of age. 165

Figure 88. Gonorrhea Cases in Illinois, 2001-2006

30000 24025 24026 21817 20597 20019 20186 20000

10000

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 89. Age Distribution of Gonorrhea Cases in Illinois, 2006

800 600 400 200 Incidence 0 0-4 5-9 yr 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-54 55-64 65+ yrs yrs y rs yrs yrs yrs yrs yrs yrs yrs Year

166 Syphilis

Background Syphilis is a systemic disease caused by the spirochete . The infection is definitively diagnosed through microscopic examination of lesion exudates and presumptively through serologic testing. Without treatment, syphilis infection progresses through four stages: primary, characterized by a painless ulcer at the point at which the organism entered the body (genitals, mouth, anus); secondary, characterized by lesions, rashes, hair loss, lymphadenopathy and/or flu-like symptoms; latent with no signs or symptoms; and late symptomatic, in the form of neurosyphilis (with neurologic damage) and tertiary (cardiovascular or gummatous disease). The open lesions of syphilis are infectious to sex partners. Syphilis during pregnancy can lead to a congenital form of the disease that may result in stillbirth or severe illness and lifelong debilitating consequences for the infant. Increases in syphilis often are associated with poverty, limited availability of health services and the exchange of sex for drugs or money. Syphilis outbreaks are often a precursor of HIV increases in affected populations because the lesions caused by syphilis increase the likelihood of both acquisition and transmission of HIV. Without treatment, approximately 10 percent of persons with syphilis will develop neurosyphilis, but in persons co-infected with HIV, 25 percent may develop neurosyphilis. “Early syphilis” refers to syphilis infection of less than one year duration and progresses through: primary, secondary and early latent. Public health disease intervention efforts emphasize control of early syphilis because persons with this stage of the disease are most likely to have been infectious within the past year. Many individuals do not notice or recognize the symptoms of syphilis, so screening for latent disease and partner notification and referral are important components of control efforts. occurs when the syphilis organism is transmitted from a pregnant woman to her fetus. Untreated syphilis during pregnancy can result in stillbirth, neonatal death or infant disorders such as deafness, bone deformities, and neurologic impairment. Significant public health resources must be devoted to control of syphilis. Untreated syphilis can result in neurological or cardiovascular complications. It also can be transmitted to a fetus from an infected woman during pregnancy, which results in congenital syphilis. The CDC recorded 431 primary and secondary syphilis cases in the United States in 2006. The rate of infection was 3.3 per 100,000 population. In 2006, a total of 349 cases of congenital syphilis were reported. The number of primary and secondary cases increased for the sixth consecutive year. Sixty-four percent of cases were reported from men who have sex with men.

Case definition Syphilis is a complex disease with a highly variable clinical course. The following case definitions are used for surveillance purposes for syphilis that has not progressed to late symptomatic stages.

• Primary. A clinically compatible case with one or more ulcers () consistent

167 with primary syphilis and a reactive serologic test; or demonstration of T. pallidum in clinical specimens by dark field microscopy, fluorescent antibody or equivalent methods.

• Secondary. A clinically compatible case with a reactive nontreponemal test titer of > 1:4 (probable case), or demonstration of T. pallidum in clinical specimens by dark field microscopy, fluorescent antibody or equivalent methods (confirmed case). • Latent. No clinical signs or symptoms of syphilis and the presence of one of the following: o No past diagnosis of syphilis, a reactive nontreponemal test and a reactive treponemal test. o A past therapy and a current nontreponemal test titer demonstrating fourfold or greater increase from the last nontreponemal test titer.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 - Sixteen congenital cases and 431 primary or secondary cases were reported (Figure 90). Primary and secondary cases decreased 18 percent between 2005 and 2006. Congenital syphilis decreased 61 percent from 2002 to 2006. The incidence rate was 5.6 per 100,000 population for primary and secondary syphilis and 8.9 per 100,000 live births for congenital syphilis. Note: CDC summaries show 15 congenital syphilis cases reported from Illinois in 2006. We will use 16 cases in this report. • Age - The average age of persons diagnosed with primary and secondary syphilis is 34 years. Adults aged 30 and older accounted for 60 percent of primary and secondary cases (Figure 91). • Gender - Ninety-one percent of primary and secondary cases were male. • Race/ethnicity - The proportion of primary and secondary syphilis cases by race were non-hispanic white (38 percent), non-hispanic African American (44 percent), hispanic (13 percent), and other or unknown races (5 percent). • Geographic distribution - Syphilis is more prevalent in urban populations.The disease has become progressively concentrated geographically. Cases of primary and secondary syphilis were reported from 24 counties. The five highest incidence rates per 100,000 population in counties with at least three cases were Vermilion (3.6), Cook (6.5), Champaign (4.5), St. Clair (3.3) and Dupage (2.0). Four counties reported congenital syphilis cases. • Clinical presentation – During 2006, there were 34 cases of reported neurosyphilis; (94 percent) of the 2006 cases were in men. Of the 32 males, 31 percent were MSM. Thirty-seven percent of the primary and secondary cases were known to be co-infected with HIV.

Summary Primary and secondary syphilis cases decreased by 18 percent in 2006 compared to 2005. During 2006, white males and African American females were disproportionately affected by syphilis.

168

Figure 90. Syphilis Cases in Illinois, 2001-2006

525 600 479 431 409 374 386 400 Primary and Secondary

200 Congenital 45 41 21 25 25 16

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 91 . Age Distribution of Syphilis Cases in Illinois, 2006

15 10 5 Incidence 0 0-4 yrs 5-9 yr 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-54 55-64 65 + y rs yrs yrs yrs yrs y rs yrs yrs yrs yrs Year

169 Shigellosis

Background Shigellosis is an acute bacterial disease of humans and non-human primates caused by four species or serogroups of Shigella: S. dysenteriae (group A), S. flexneri (group B), S. boydii (group C) and S. sonnei (group D). The infectious dose is low; as few as 10 to 100 bacteria can cause infection. Transmission is via direct or indirect fecal-oral routes. Outbreaks in day care centers are not uncommon and Shigella can be transmitted through unchlorinated wading pools, interactive water fountains, food items such as parsley and bean dip and between men who have sex with men. The incubation period is usually one to three days. Symptoms of the disease are watery or bloody diarrhea with fever and sometimes vomiting or tenesmus. Mild and asymptomatic infections can occur. Duration of illness is usually from four to seven days. Shigella can be shed in stool for four weeks. Disease caused by Shigella dysenteriae type 1 is the most severe and can cause hemolytic uremic syndrome (HUS) due to a toxin similar to that produced by E. coli O157:H7. Antimotility drugs are contraindicated. Antimicrobial therapy can limit the clinical course and duration of fecal excretion of Shigella. Shigella can develop antimicrobial resistance quickly. The subgroups, serotypes and subtypes of Shigella are: Group A: Shigella dysenteriae 15 serotypes (type 1 produces Shiga toxin) Group B: 8 serotypes and 9 subtypes Group C: 19 serotypes Group D: 1 serotype Of the ten diseases/syndromes (caused by Campylobacter, Cryptosporidium, Cyclospora, HUS, E. coli O157:H7, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites, Shigella comprised 2,736 of 17,252 (16 percent) of the reported infections in 2006 in preliminary data. The incidence rate overall was six per 100,000 for shigellosis and ranged from 0.9 to 15 at the 10 FoodNet sites for preliminary 2006 data. The number of Shigella infections decreased from baseline by 35 percent in 2006 at these sites. In 2006, 15,503 Shigella cases were reported to CDC. S. sonnei accounts for more than 75 percent of shigellosis cases in the United States. In 2002, from six states reporting nationally to CDC, the median time from onset of symptoms to PFGE typing was 21 days. The median interval from onset of illness to interview of patient was 14 days. Multi-community outbreaks of shigellosis require extensive time and effort on the part of public health. Because of the low infectious dose, shigellosis spreads quickly between people when breaches in handwashing or sanitation occur. Propagation of shigellosis is increased because of the difficulty in maintaining handwashing and sanitation in day care centers, high proportion of mild or asymptomatic Shigella infections and frequent contact between children who attend multiple day care centers. Interventions include alerting the media to the outbreak, direct communication with day care centers and the medical community, and promoting control strategies such as supervised handwashing and exclusion of symptomatic children from day care. However, strict exclusion policies of infected but asymptomatic children can lead to spread of an outbreak if excluded day care attendees are then placed in alternative

170 child care settings.

Case definition The case definition for a confirmed case of shigellosis in Illinois is a case from which Shigella is isolated from a clinical specimen. The case definition for a probable case is a person who has a clinically compatible illness that is epidemiologically linked to a confirmed case, but is not laboratory confirmed.

Descriptive epidemiology • Number of reported cases in Illinois in 2006 - There were 720 cases reported (five-year median = 630; see Figure 92). Overall annual incidence rate was six per 100,000. Of the cases, 628 were confirmed and 92 were probable. • Age – The mean age of cases was 40 years (Figure 93). By age group, annual incidence rates per 100,000 were: less than 1 year old (eight); 1 to 4 years of age (28); 5 to 9 years of age (16); 10 to 19 years of age, (four); 20 to 29 years of age, (five); 30 to 59 years of age (two); and 60 and older (one). • Gender – Fifty-two percent were female. • Race/ethnicity – Fifty-four percent were white, 33 percent were African American, and 13 percent were other races; 37 percent were Hispanic. There were significantly higher proportions of Hispanics with shigellosis (37 percent) compared to their representations in the Illinois population (12 percent). • Geographic distribution – For 2006, counties with the highest incidence per 100,000 were Morgan (309), Kankakee (79), St. Clair (20), Scott (18) and Adams (18). Figure 94 shows county incidence for the state. • Clinical syndrome – Symptoms reported included diarrhea (98 percent), fever (70 percent) and vomiting (48 percent). • Outcome – Thirty-two percent of cases were hospitalized. No fatalities were reported. • Seasonal variation - Shigellosis cases occurred in all months of the year with a peak in the month of August (Figure 95). • Serotypes - Ninety-five percent of isolates were serotyped in 2006. The most common species was S. sonnei (86 percent of typed isolates), followed by S. flexneri (13 percent). S. boydii and S. dysenteriae each made up less than one percent of typed isolates. The boydii serotypes found in Illinois were 1, 2 and 12, and the dysenteriae serotypes were 2 and 3 (Table 12 and 13). The three most common S. flexneri serotypes were 2 (23 cases), 3 (14 cases), and 1 (13 cases) (Table 14). S. sonnei does not have subtypes, but there were 584 S. sonnei cases reported. • Reporter – Fifty-four percent were reported by infection control professionals and 41 percent by laboratories. • Risk factors o Fifty-one cases acquired infection in another country. Mexico was the most frequent country where acquisition occurred (23, 45 percent). o Ten cases acquired infection in another state. The most frequent state mentioned was Florida (three cases).

171 o Twenty-four of 521 (5 percent) reported swimming in non-chlorinated water, and 47 of 510 (9 percent) swam in chlorinated water. o Forty-four cases attended day care and four attended a residential facility. o Of 573 cases, 163 (28 percent) reported contact with someone attending a day care center. Seventy-three of 531 cases (14 percent) reported contact with someone in a residential facility. o One person of 394 reported drinking water from a well. • Sensitive occupations – Cases were employed in the following sensitive occupations: day care (nine), food service (eight), health care (six), residential facility (two), and other sensitive occupations (10). • Foodborne outbreaks – There were no foodborne outbreaks of shigellosis in 2006. • Person-to-person outbreaks – Five person-to-person outbreaks were reported. See non-foodborne, non-waterborne section for details.

Summary There was an increase in Shigella cases from 2005 to 2006. The incidence rate for 2006 of six per 100,000 is within the range reported at CDC’s FoodNet sites. The proportion who were Hispanic was higher than the representation of hispanics in the Illinois population. The mean age of cases was 40 years. Ninety-five percent of isolates were serotyped. S. sonnei was the most common serotype found in Illinois, which is the same as the most common serotype identified in CDC’s FoodNet sites. Isolates of Shigella are required to be submitted to the Department’s laboratories for speciation and/or serotyping (if this cannot be done by the clinical laboratory).

Suggested readings Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from http://www.cdc.gov/EID/content/14/2/311

Figure 92. Shigella Cases in Illinois, 2001-2006

1500 1105 1006 1000 630 720 402 409 500

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

172 Figure 93. Age Distribution of Shigella Cases in Illinois, 2006

40 30 Male 20 Female

Incidence 10 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age category

Figure 94. Shigella Cases in Illinois by Month, 2006

200 150 100 50

Number of cases 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

173 Figure 95. Shigellosis Incidence Rates by County for Illinois, 2006

Jo Daviess StephensonWinnebago McHenry Lake Boone

Carroll Ogle Kane DeKalb DuPageCook Whiteside Lee Kendall Will Rock Island Bureau Henry La Salle Grundy Mercer Putnam Kankakee Stark Marshall Knox Livingston HendersonWarren Woodford Peoria Iroquois

Ford McDonough Tazewell McLean Hancock Fulton

Mason Schuyler De Witt Vermilion Logan Champaign Menard Piatt Adams Cass Brown Macon Sangamon Douglas Morgan Edgar Pike Moultrie Scott Christian Coles Shelby Greene Clark Macoupin Cumberland Calhoun Montgomery Jersey Effingham Fayette Jasper Crawford Bond Madison Clay RichlandLawrence Marion Clinton St. Clair Wayne Wabash Washington Edwards Monroe Jefferson

Randolph Perry HamiltonWhite Franklin

Jackson SalineGallatin Williamson

Johnson Hardin Union Pope

AlexanderPulaski Massac

Source: Illinois Department of Public Health

174

175 Table 12. Frequency of Shigella boydii in Illinois, 1999-2006 Type 1999 2000 2001 2002 2003 2004 2005 2006 boydii, unknown 0 0 0 0 0 0 0 0 boydii 1 0 0 2 0 0 0 0 1 boydii 2 4 4 3 1 5 1 1 1 boydii 3 0 0 0 1 0 0 0 0 boydii 4 7 2 0 2 2 1 1 0 boydii 5 0 1 0 0 0 0 0 0 boydii 8 0 0 0 0 0 2 0 0 boydii 10 1 0 0 0 0 0 0 0 boydii 11 0 1 0 0 0 0 0 0 boydii 12 1 0 0 0 0 0 0 1 boydii 13 0 1 0 0 0 0 0 0 boydii 14 2 2 1 2 1 0 0 0 boydii 18 4 1 0 0 0 1 0 0 boydii 19 0 0 0 0 0 0 0 0 boydii 20 0 0 0 0 0 1 0 0 TOTAL boydii 19 12 6 3 8 6 2 3 Source: Illinois Department of Public Health

Table 13. Frequency of Shigella dysenteriae in Illinois, 1999-2006 Type 1999 2000 2001 2002 2003 2004 2005 2006 dysenteriae, 0 2 0 0 1 1 0 1 unknown dysenteriae 1 1 0 0 0 0 1 0 0 dysenteriae 2 4 0 0 0 2 0 0 1 dysenteriae 3 0 0 0 1 0 1 0 1 dysenteriae 4 0 0 0 1 0 0 3 0 dysenteriae 9 0 0 0 0 0 0 0 0 dysenteriae 12 0 0 0 0 0 0 0 0 TOTAL 5 2 0 2 3 3 3 3 dysenteriae

176 Source: Illinois Department of Public Health Table 14. Frequency of Shigella flexneri subtypes in Illinois, 1999-2006 Type 1999 2000 2001 2002 2003 2004 2005 2006 flexneri, unknown 39 31 24 14 15 14 11 21 flexneri 1 11 3 5 8 9 8 11 13 flexneri 1A 0 0 0 0 0 0 0 0 flexneri 1B 1 0 0 0 0 0 0 1 flexneri 2 64 49 23 36 33 36 29 23 flexneri 2A 1 0 0 0 1 0 0 0 flexneri 2B 0 0 0 1 0 1 0 0 flexneri 3 24 27 14 7 29 7 14 14 flexneri 3A 0 0 0 0 0 0 0 3 flexneri 3B 0 0 0 0 0 0 0 1 flexneri 4 15 10 11 23 11 23 7 11 flexneri 4A 0 1 0 0 1 0 0 0 flexneri 4B 0 0 0 0 0 0 0 0 flexneri 5 0 0 0 0 0 0 0 0 flexneri 5A 0 0 0 0 0 0 0 0 flexneri 6 11 8 9 8 7 8 0 3 flexneri X variant 0 0 0 1 1 1 2 0 flexneri Y variant 0 1 3 1 0 1 5 2 TOTAL flexneri 166 130 89 99 107 99 79 92

Source: Illinois Department of Public Health

177 Staphylococcus aureus, Intermediate or High Level Vancomycin Resistance

Background Staphylococcus aureus causes both community and health care associated infections in persons. The National Committee for Clinical Laboratory Standards (NCCLS) defines staphylococci requiring concentrations of vancomycin of < 4 ug/mL for growth inhibition as susceptible to vancomycin. Those requiring concentrations of eight to 16 ug/mL as intermediate and those requiring concentrations of at least 32 ug/mL as resistant. S. aureus with reduced vancomycin susceptibility (SA-RVS) includes all S. aureus isolates with MICS of vancomycin of at least four ug/mL. Three cases of SA-RVS have been identified in Illinois, two in 1999 and one in 2000.

Case definition A case of S. aureus, intermediate or high level vancomycin resistance is defined as S. aureus isolated from infected humans with an MIC of vancomycin of at least four ug/mL.

Descriptive epidemiology No cases were reported in 2006.

Summary No cases were reported in 2006 in Illinois.

178 Streptococcus pyogenes, Group A (Invasive Disease)

Background The spectrum of disease caused by group A streptococci (GAS) is diverse and includes and , severe invasive infections, post-streptococcal acute rheumatic fever and acute glomerulonephritis. Invasive GAS may present as any of several clinical syndromes including pneumonia, bacteremia in association with cutaneous infection (, or infection of a surgical or nonsurgical wound), deep soft tissue infection (myositis or ), meningitis, peritonitis, osteomyelitis, septic arthritis, postpartum sepsis (puerperal fever), and non-focal bacteremia. Two types of invasive GAS are streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis. The symptoms of STSS include fever, myalgia, vomiting, diarrhea, confusion, soft tissue swelling, renal dysfunction, respiratory distress and shock. Necrotizing fasciitis is a deep infection of subcutaneous tissue that results in destruction of fat and fascia and often leads to systemic illness. Risk factors for necrotizing fasciitis include injection drug use, obesity and diabetes mellitus. Transmission of GAS occurs by direct contact with patients or carriers, or by inhalation of large respiratory droplets. Approximately 5 percent of the population may be asymptomatic carriers, but these individuals are less likely to transmit the organism than symptomatic persons. Predisposing risk factors for invasive GAS include older age, injection drug use, human immunodeficiency infection, diabetes, cancer, alcohol abuse, varicella, penetrating injuries, surgical procedures, childbirth, blunt trauma, and muscle strain. Treatment guidelines have been established by the Infectious Diseases Society for GAS pharyngitis. Chemoprophylaxis is not recommended for all household contacts to cases of invasive GAS. Household members should monitor themselves for signs and symptoms for 30 days after exposure. During 2006, 1,146 cases of invasive GAS were reported from the Active Bacterial Core Surveillance site projects in 10 states. Incidence was highest in adults greater than 64 years (10 cases per 100,000), children younger than 1 year of age (5.1 cases per 100,000) and 50 to 64 year olds (5.0 per 100,000). STSS accounted for 5 percent, and necrotizing fasciitis accounted for 7 percent of cases. The overall case fatality rate was 14 percent. In routine surveillance, 5,407 cases of invasive GAS were reported to CDC and 125 cases of streptococcal TSS.

Case definition The case definition of invasive GAS disease in Illinois is the isolation of group A Streptococcus pyogenes by culture from a normally sterile site.

Descriptive epidemiology • Number of reported cases in Illinois in 2006 – There were 326 invasive GAS cases including nine necrotizing fasciitis and 19 streptococcal toxic-shock syndrome cases (five-year median = 326) (see Figure 96). All cases were confirmed. The incidence rate for 2006 was three per 100,000 population. • Age - Mean age was 51 (Figure 97). By age group, the highest incidence per

179 100,000 occurred in those older than 79 years of age (14 per 100,000 in that age group), followed by those 70 to 79 years of age (7.5 per 100,000) and 60 to 69 years of age (5.6 per 100,000). At least 39 cases were residents of residential institutions. • Gender – Fifty-one percent were male. • Race/ethnicity - Cases were 71 percent white, 17 percent African American and 7 percent other races; 14 percent occurred among Hispanics. • Geographic distribution – Forty-five percent of cases were residents of Cook County. Cases were reported from 46 counties. • Seasonal variation - An increase in cases occurred from January to March (Figure 98). • Positive cultures - The number of positive cultures by type of specimen were blood - 270 (83 percent of all cultures), unspecified tissue - 10 (3 percent), synovial fluid - nine (3 percent), blood plus other source – 21 (6 percent), other – 12 (4 percent) and unknown – four (1 percent). • Outcome – Ninety-five percent were hospitalized. Twenty-nine of 198 cases were fatal (overall case fatality rate - 15 percent). Seventy–six percent of the fatalities were in those older than 49 years of age (mean = 60 years). The highest fatality rate occurred in those with toxic shock syndrome (71 percent), followed by necrotizing fasciitis (25 percent) and invasive GAS only (10 percent). • Reporting – Seventy-seven percent were reported by infection control professionals, and 21 percent were reported by laboratories. • Clusters – Two clusters were reported. See non-foodborne, non-waterborne outbreak section for details.

Summary The number of reported invasive GAS cases continues to rise in Illinois. The highest incidence was in those older than 79 years of age. Seventy-six percent of the fatalities were persons older than 49 years of age. Illinois had the second highest number of streptococcal toxic shock cases reported in the United States.

Figure 96. Invasive GAS Cases in Illinois, 2001-2006

500 417 400 326 342 326 272 284 300 200 100

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Ye ar

180 Figure 97. Invasive GAS and Streptococcal TSS Cases by Age in Illinois, 2006

13.6 15 10 7.5 5.6 3 2.3 3.2 5 2 0.7 1

Incidence 0.2 0 0-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr 60-69 yr 70-79 yr 80+ Age Group

Figure 98. Invasive GAS and Streptococcal TSS Cases in Illinois by Month, 2006

60 40 20 0 Number of cases Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of Onset

181 S. pneumoniae

Background S. pneumoniae is the most common cause of meningitis, community-acquired pneumonia and bacteremia, and acute otitis media. Pneumococci colonize the nasopharynx of 15 percent to 60 percent of individuals; most remain asymptomatic. Carriage is higher in children attending child care centers outside the home. The onset of S. pneumoniae meningitis is usually sudden with high fever, lethargy and signs of meningeal irritation. It is a sporadic disease in the elderly and in young infants. In the nine states which are part of the Active Bacterial Core Surveillance, isolates were collected in 2006, 15 percent exhibited intermediate resistance to , and 10 percent were fully resistant. The pneumococcal conjugate 7-valent vaccine (6B, 14, 18C, 19F, 23F, 9V, 4) was licensed in the United States in February 2000 and can be used in children younger than 2 years of age. The vaccine protects against the seven strains of pneumococcus that cause 80 percent of the invasive disease among children in the United States. Individuals at the extremes of age and in certain ethnic groups (African American, American Indians and Alaskan natives) are disproportionately affected. Males are at higher risk for S. pneumoniae. Other risk factors for invasive disease include renal dysfunction, sickle cell disease, alcoholism, smoking, HIV, organ transplantation and diabetes mellitus. In data for 2006 from the national Behavioral Risk Factor Surveillance system, the percent of persons older than the age of 64 who had received at least one pneumococcal vaccination was 60 percent. The Healthy People 2010 objectives are to reduce invasive pneumococcal disease to 46 per 100,000 in children younger than five years and to 42 per 100,000 in adults aged 65 years or older. Since vaccine has been available incidence has declined.

Case definition A case is defined as a person with clinically compatible symptoms and from whom isolation of the organism from a normally sterile site has occurred. In INEDSS, cases with MMWR year of 2006 were chosen for the information reported below. This includes all invasive S. pneumoniae. CDC only required reporting of some S. pneumoniae cases so their numbers will not match the numbers below.

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – 1,150 (five-year median = 936) (See Figure 99). The incidence rate for 2006 was 9.2 per 100,000. CDC recorded 33 drug resistant cases from Illinois and 106 non drug resistant cases in children less than five years. Information provided below is for 1,150 cases. • Age - Mean age of cases was 55 years (see Figure 100 for age distribution). • Gender – Fifty-two percent were female. • Race/ethnicity - Twenty-two percent were African American, 74 percent were white and 3 percent were other races; Eight percent were Hispanic. • Seasonal peak – An increase in cases occurred in the winter and spring months

182 (Figure 101). • Clinical - Ninety-one percent of cases were hospitalized. Nine percent of cases were fatal.

Summary More than one thousand cases of invasive S. pneumoniae were reported in Illinois in 2006.

Suggested readings CDC. 2007: Active bacterial core surveillance report, Emerging Infections Program Network, Streptococcus pneumonia, 2006. Available at: www.cdc.gov/ncidod/dbmd/abcs/survreports/spneum06.pdf Grijalva, C.G., et.al. Pneumonia hospitalizations among young children before and after introduction of pneumococcal conjugate vaccine-United States, 1997-2006. MMWR 58(1):1-4. Kilmer, G., et. al. Surveillance of certain health behaviors and conditions among states and selected local areas – Behavioral risk factor surveillance system (BRFSS), United States, 2006. MMWR 2008; 57(SS-7):p.59. Wooten, K.G. et al. National, state and local area vaccination coverage among children aged 19-35 months-United States, 2006. MMWR 2007;56(34): 880-5.

Figure 99. S. pneumoniae Cases in Illinois, 2001-2006

1500 1226 1150 1012 936 1000 823 491 500

Number Number of cases 0 2001 2002 2003 2004 2005 2006 Year

Figure 100 . S. pneumoniae Cases by Age in Illinois, 2006

40 30 20 10 0

Incidence per 100,000 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-59 yr >59 yr Age group

183 Figure 101 . S. pneumoniae Cases in Illinois by Month, 2006

200 150 100 50

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

184 Tetanus Background Tetanus is non-communicable. Clostridium tetani spores can be present in the environment and enter the body through nonintact skin. Generalized tetanus presents with trismus (lockjaw) followed by generalized rigidity caued by contractions of the skeletal muscles. Forty-one cases were reported in the United States in 2006. Mortality was associated with underlying diabetes, IV drug use and advanced age.

Case definition A confirmed case of tetanus is a clinically compatible case, as reported by a health care professional.

Descriptive epidemiology One case was reported in Illinois in October in an 81-year-old male from Whiteside county. The patient was hospitalized for 24 days and on mechanical ventilation. The patient had a wound from working in the yard on October 12 and did not seek medical attention until symptoms of tetanus began on October 20. His last dose of tetanus toxoid was nine years prior to onset.

185 Tickborne Diseases Found in Illinois Ticks are the most common vector of vectorborne diseases in the United States. Ticks are responsible for the following diseases in the United States: babesiosis, Colorado tick fever, human granulocytic ehrlichiosis, human monocytic ehrlichiosis, Lyme disease, Powassan encephalitis, relapsing fever, Rocky Mountain spotted fever (RMSF), tick paralysis and tularemia. Ticks usually attach around the head, neck and groin of the human host. The rates of human infection with tickborne diseases are influenced by the prevalence of vector tick species, the tick infection rate, the readiness of ticks to feed on humans, and the prevalence of their usual animal hosts. Seven tickborne diseases have been reported in Illinois residents. Six of these tickborne diseases are listed in Table 15 and in individual sections of this document. Six cases of babesiosis have been reported in Illinois residents from 1991 through 2006 and all cases were acquired out of state. According to CDC guidelines, any Illinois resident diagnosed with a tickborne disease is counted in the state’s case count, even though he/she may have reported tick exposures in another state. Case counts by year for 2001 through 2006 for four of these infections that occur regularly in Illinois are shown in Figure 102. Number of ehrlichiosis and Rocky mountain spotted fever cases increased in 2006 as compared to previous years.

Figure 102. Tickborne Disease Cases in Illinois, 2001-2006 127 150 110 71 87 100 47 32 26 32 cases 50 1214 7 12 5 6 5 1 9 14 5 12 11 1 7 1 Number of of Number 0 2001 2002 2003 2004 2005 2006 Year

Lyme RMSF Tularem ia Ehrlichiosis

186 Table 15. Tickborne Diseases Reported in Illinois Residents

Disease Organism Tick vectors Symptoms Where found

Rocky Mountain Rickettsia Dermacentor fever, headache, throughout the spotted fever rickettsii variabilis rash United States but (American dog most common in tick), Southeast; entire D. andersoni state of Illinois (Rocky Mountain wood tick)

Tularemia Francisella Amblyomma ulcer at entry site, throughout North tularensis americanum enlarged lymph America; primarily (lone star tick), node central and southern Illinois D. variabilis, D. andersoni

Lyme disease Borrelia Ixodes scapularis fatigue, chills, primarily on the burgdorferi (deer tick) fever, erythema West Coast, in migrans, enlarged northeastern and lymph nodes north central United States; primarily northern Illinois

Human monocytic Ehrlichia A. americanum fever, headache, most common in ehrlichiosis chaffeensis myalgia, vomiting the southern states; more common in southern Illinois

Human Anaplasma I. scapularis fever, headache, most common in granulocytic phagocytophilum myalgia, vomiting upper Midwest ehrlichiosis and Northeast; in Illinois, unknown distribution * Although suspected to be present in Illinois, no diagnostic test is available yet.

187 Toxic Shock Syndrome (TSS) Due to Staphylococcus aureus Background Toxic shock syndrome is classified by clinical and laboratory evidence of fever, rash, desquamation, hypotension and multiple organ failure caused by toxins produced by Staphylococcus aureus. MRSA strains have caused TSS in other countries. Most cases have been associated with strains of Staphylococcus aureus that produce a special toxin. In 2006, 101 cases were reported to CDC nationally.

Case definition The five clinical findings used to establish whether a case meets the case definition for staphylococcal TSS are - 1) Fever - temperature greater than 102 F 2) Rash 3) Desquamation 4) Hypotension 5) Multisystem involvement (three or more of the following) a. Gastrointestinal - vomiting or diarrhea b. Muscular - myalgia or creatine phosphokinase (at least twice upper limit of normal) c. Mucous membrane - vaginal, oropharyngeal or conjunctival hyperemia d. Renal - blood urea nitrogen or creatinine at least twice the upper limit of normal or urinary sediment with pyuria in the absence of urinary tract infection e. Hepatic - total bilirubin, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) at least twice the upper limit of normal for the lab f. Hematologic - platelets less than 100,000/mm3 g. CNS - disorientation or alterations in consciousness without focal neurologic signs when fever and hypotension are absent. In addition, there should be negative results on the following tests (if done) a. Blood, throat or CSF cultures (blood cultures can be positive for S. aureus) b. Rise in titer to Rocky Mountain spotted fever, leptospirosis or measles

The CDC case definition for a probable case is one with any four of the five clinical findings above. A confirmed case is one with all five of the clinical findings, including desquamation, unless the patient dies before desquamation can occur.

Descriptive epidemiology

• Number of cases reported in Illinois in 2006 - Two cases were reported (five-year median = five cases). One was confirmed, and one was probable. • Age - Ages were 33 and 36. • Gender - Both cases were female. • Seasonality – Cases had onsets in March.

188 • Race/ethnicity – One case was white; the other did not report race. One case with information available was not Hispanic. • Geographic distribution - Cases resided in Cook and Kane counties. • Treatment - Both patients were hospitalized. • Outcome – One case was fatal. • Reporting – One case was reported by a hospital; the other by a laboratory. • Past cases – Toxic shock syndrome cases due to S. aureus reported per year in the state previously were 1998 (seven), 1999 (five), 2000 (three), 2001 (four), 2002 (five), 2003 (six), 2004 (six) and 2005 (five).

Summary Two cases of staphylococcal toxic shock were reported in 2006 and were considered to be associated with .

189 Tuberculosis

Background The Mycobacterium tuberculosis complex includes M. tuberculosis, M. africanum, M. bovis and M. microti. Tubercle bacilli are transmitted by inhalation of airborne droplet nuclei produced by persons with tuberculosis (TB) disease. Prolonged close contact with cases may lead to latent TB infection (LTBI). Tuberculin skin sensitivity often indicates LTBI (as noted by a positive skin test), which usually appears four to 12 weeks after infection. LTBI is different from TB disease and is defined as a condition in which TB bacteria are alive but inactive in the body. People with latent TB infection have no symptoms and cannot spread TB to others. They usually have a positive skin test reaction and may develop TB disease later in life if they do not receive treatment for latent TB infection. Approximately 90 to 95 percent of newly infected individuals have LTBI where early lung lesions heal and leave no residual changes except small calcifications in the pulmonary or tracheobronchial lymph nodes. In those patients whose infection progresses to disease, early symptoms may include fatigue, fever, night sweats and weight loss. In advanced disease, symptoms such as cough, chest pain, coughing up of blood, and hoarseness may occur. Several issues, such as patients’ immune status and immigration from areas where TB is common, impact the incidence of TB in Illinois. In 2006, CDC recommended routine HIV screening for all TB patients, unless the patient declines to accept testing. The AIDS epidemic had a profound effect on the number of TB cases in Illinois in the past. TB is a major in HIV-infected persons. HIV contributes to TB because immune suppression increases the likelihood of rapid progression from TB infection to TB disease. In Illinois, the percentage of TB cases diagnosed in foreign-born individuals is increasing. CDC recommends that all immigrants, refugees, foreign-born students and their families, and others accompanying them into the country be tuberculin-test screened and medically treated when appropriate. Both suspected and confirmed cases of TB are reportable in Illinois. The sooner cases are reported to the local TB control authority, the sooner their personnel can begin investigations which may interrupt transmission of TB in the community. Extensively drug resistant (XDR) TB is TB which is resistant to isoniazid and rifampin and resistance to any fluoroquinolone, and resistance to at least one second-line injectable drug (amikacin, capromycin or kanamycin). From 1993 to 2006, 49 TB cases in the United States were classified as XDR-TB including one case from Illinois. The recommended length of drug therapy for most types of TB is six to nine months. Treatment of multi-drug resistant TB requires administration of four to six drugs for 18 to 24 months. Patients with both TB and HIV are more likely to die during anti-TB treatment than patients not infected with HIV. During 2006, a total of 13,779 cases (4.6 per 100,000) were reported to CDC. Forty-three percent were among United States-born persons (2.3 per 100,000 population). In 2006, the overall TB case rate was 9.5 times higher in foreign-born persons than among United States-born persons.The rate was higher than the 2010 national objective of less than one case per 1,000,000 population. The highest rates

190 were in African Americans and Asians.

Case definition A confirmed case of tuberculosis in Illinois is a case that is either laboratory confirmed or is a case that meets the clinical case definition criteria: 1) A positive tuberculin skin test 2) Other signs and symptoms compatible with tuberculosis, such as an abnormal, unstable chest radiograph, or clinical evidence of current disease 3) Treatment with two or more anti-tuberculosis medications 4) Completed diagnostic evaluation

Laboratory criteria for diagnosis are isolation of M. tuberculosis from a clinical specimen, demonstration of M. tuberculosis from a clinical specimen by DNA probe or mycolic acid pattern on high-pressure liquid chromatography, or demonstration of acid- fast bacilli in a clinical specimen when a culture has not been or cannot be obtained.

Descriptive epidemiology

• Number of cases reported in Illinois in 2006 – 569 (4.4 per 100,000 population). (Figure 103). • Age - The highest incidence of TB occurred in the 45 to 64 and 65 and older age groups (Table 16). • Gender – Fifty-nine percent were male. • Race/ethnicity – Thirty-five percent were African American (non-Hispanic), 16 percent white (non-Hispanic), 34 percent Hispanic and 24 percent were Asian or Pacific Islander. ► The number and percent of foreign-born TB cases increased in 2006 (N = 305, or 54 percent) as compared to 2005 (N = 268 or 45 percent) (Figure 104). Cases were born in 52 foreign countries. The largest number of cases were born in Mexico (29 percent), followed by India (18 percent) and the Philippines (13 percent). Persons born in China, Viet Nam and South Korea (11 percent combined) also were represented among foreign-born cases. • Risk factors – Risk factors included homeless in past 12 months (5 percent), being an inmate in a correctional facility (4 percent), injection drug use (2 percent) and residing in a long-term care facility (2 percent). • Diagnosis – Seventy-seven percent of cases were culture confirmed, 12 percent were provider diagnosed, 10 percent were clinically diagnosed and 0.9 percent were smear positive. • Drug resistance – One MDR and no XDR-TB cases were reported. • Clinical syndrome – Sixty-five percent of cases were pulmonary, 27 percent were extrapulmonary and 7 percent were both. Between 2002 and 2006, there were 78 percent of 1,036 TB cases aged 25 to 44 that had a valid HIV status. Twelve percent were HIV positive.

191 Summary In 2006, 569 cases of TB were reported in Illinois with an incidence rate of 4.4 per 100,000, which is very similar to the national incidence rate. Fifty-four percent of these cases were among persons born outside of the United States. An increasing percentage of foreign-born cases are being seen in Illinois, with India, Mexico and the Philippines being the most common countries of origin. This is the first year in Illinois that foreign-born cases outnumbered U.S. born cases. Public health attention must continue to focus on high-risk groups, especially those born outside of this country. Illinois is one of seven states reporting more than 500 cases and is fifth in the nation in the number of cases reported.

Suggested readings Pratt, R., et al. Trends in tuberculosis in tuberculosis incidence-United States, 2006.MMWR 2007;56(11):245-250. Shah, N.S., et al. Extensively drug-resistant tuberculosis-United States,1993- 2006. MMWR 2007; 56(11):250-53.

Table 16. Age Distribution of Tuberculosis Cases in Illinois, 2006

Age Incidence *

< 5 years 3.2

5 – 14 0.8

15 – 24 2.9

25-44 4.7

45-64 6.0

65+ 7.6

All 4.4

U.S. 4.6 * Incidence per 100,000 based on 2000 population. Source: Illinois Department of Public Health

192

Figure 103. Tuberculosis Cases in Illinois, 2001-2006

448 500 415 407 400 339 328 305 259 265 273 268 264 300 230 Foreign born 200 US born 100

Number Number of cases 0 2001 2002 2003 2004 2005 2006 Year

Figure 104 . Country of Origin for Foreign-born TB Cases, Illinois, 2006 India Other 18% India 29% Mexico

China, Vietnam, South Korea Mexico Philippines Philippines 29% Other 13% China, Vietnam,

193 Tularemia

Background Tularemia is caused by and is a zoonotic disease that infects vertebrates especially rabbits and rodents. Tularemia can be classified into six primary syndromes: ulceroglandular (the most common form), glandular, typhoidal, oculoglandular, oropharyngeal, and pneumonic. The case fatality rate can be 30 percent to 60 percent if untreated and typhoidal. Tularemia can be divided into four subspecies. Human disease is mainly associated with F. tularensis subsp tularensis, found only in North America, and the moderately virulent F. tularensis subsp. Holartica, which is endemic throughout the northern hemisphere. F. tularensis subspecies tularensis can be separated into two subpopulations in the United States, A.I. and A.II. A.1. occurs primarily in the central United States and A.II. occurs primarily in the western United States. Tularemia can affect many wildlife species, including prairie dogs, squirrels, and cats in addition to humans. Both ticks and biting flies can serve as vectors in the United States. The most common modes of transmission are tick bites and handling infected animals. The disease also can spread through ingestion of contaminated water or food, inhalation, and insect bites. Tularemia has two peaks in occurrence; a peak in the summer reflects transmission from ticks and a peak in winter reflects transmission from animal contact, especially rabbits, often during hunting or trapping seasons. The most important epizootic hosts for tularemia in the United States include rodents and lagomorphs. Tularemia has been associated with die-offs in exotic pet animals, such as prairie dogs. From 1990 to 2000, tularemia was primarily reported from Arkansas, Missouri, Oklahoma and South Dakota. The most common tick vectors in the United States are the American dog tick (Dermacentor variabilis), the Lone Star tick (Amblyomma americanum) and the Rocky Mountain wood tick (D. andersoni). The incubation period is three to five days. Clinical signs in people include fever, chills, malaise, cough, myalgias, vomiting and fatigue followed by the development of one of six clinical syndromes. Isolation of F. tularensis requires biosafety level 3 facilities. Tularemia is considered a possible bioterrorism agent. Vaccination is recommended only for limited numbers of persons in high-risk occupations. In 2006, 95 cases were reported to CDC from 26 states. Prevention methods include wearing gloves when handling dead animals, especially rabbits and rodents; avoiding bites of ticks, flies and mosquitoes by using insect repellents, cooking game meat thoroughly, and avoiding drinking of untreated water.

Case definition The CDC case definition for a confirmed case of tularemia is a clinically compatible case with either isolation of F. tularensis from a clinical specimen or a four- fold or greater rise in serum antibody titer to F. tularensis antigen. A probable case is a clinically compatible case with either detection of F. tularensis in a clinical specimen by fluorescent antibody or an elevated serum antibody titer to F. tularensis antigen in a patient with no history of vaccination.

194

Descriptive epidemiology • Number of cases reported in Illinois in 2006 – One probable case was reported. • Age - The case’s age was 6. • Gender – This case was female. • Seasonal variation – The onset of illness was in August. • Geographic distribution – The exposure site for the case was Washington County. • Symptoms/diagnosis/treatment – The case was not hospitalized. A single serologic test was positive. • Exposures – The patient reported a tick bite while on his own property. • Past incidence - The numbers of cases in Illinois by year are as follows: 1991 (five), 1992 (two), 1993 (three), 1994 (three), 1995 (four), 1996 (four), 1997 (five), 1998 (five), 1999 (two), 2000 (four), 2001 (14), 2002 (five), 2003 (one), 2004 (five) and 2005 (one).

Summary The number of cases of tularemia was the same as in 2005. Only one case was reported.

195 Typhoid Fever

Background Typhoid fever is a systemic infection caused by infection with Salmonella enterica serotype Typhi. The incubation period is from three days to three months with a usual range of one to three weeks. Transmission of typhoid fever is usually by ingestion of food or water contaminated by fecal or urinary carriers of S. enterica serotype Typhi. Types of products implicated in some countries include shellfish, raw fruits, vegetables and contaminated milk or milk products. Unlike other types of Salmonella, S. enterica ser. Typhi is not found in animal reservoirs; humans are the only reservoirs. In developed countries like the United States, most cases are sporadic after travel to endemic areas. The infectious dose ranges from 1,000 to 1 million organisms. Constipation is more common than diarrhea in adults. The onset of bacteremia with typhoid fever results in fever, headache, abdominal discomfort, dry cough and myalgia. Other findings may include bradycardia, rash and splenomegaly. Complications may include gastrointestinal bleeding, intestinal perforation, and typhoid encephalopathy. Relapse may occur in 5 percent to 10 percent of patients, usually two to three weeks after resolution of fever. As many as 10 percent of untreated patients will shed organisms in the feces for up to three months. One percent to four percent may develop long-term carriage of the organism for as long as one year. Most carriers are asymptomatic. Chronic carriage is more common in women, the elderly and in patients with cholelithiasis. Typhoid fever is typically diagnosed with blood cultures. Bone marrow cultures also can be used. For travelers to developing countries, water should be boiled or bottled and food should be thoroughly cooked to avoid acquiring typhoid fever. Vaccination is recommended for persons traveling to areas where typhoid is endemic. In 2006, 353 typhoid fever cases were reported in the United States. Approximately three-quarters of all cases occur among persons who report international travel during the prior month. Persons visiting South Asia are at particular risk.

Case definition A confirmed case is a clinically compatible illness with isolation of S. enterica ser. Typhi from blood, stool or other clinical specimen. A probable case is defined as a clinically compatible illness that is epidemiologically linked to a confirmed case in an outbreak.

Descriptive epidemiology

• Number of cases reported in Illinois in 2006 – 18 (five-year median = 17) (see Figure 105). All were confirmed cases. • Sex – Eleven (61 percent) were male. • Age - Cases ranged in age from 11 months to 73 years of age (median = 17 years). • Race/ethnicity – Eleven of 18 (61 percent) were Asian; four (22 percent) were white, none were African American, and three (17 percent) were other races. Three of 16 cases (19 percent) were Hispanic. • Seasonal variation – Cases were reported from January through November.

196 • Geographic distribution – Sixty-one percent of the cases were Cook County residents. • Reporting – Thirty-nine percent were reported by infection control professionals, and 61 percent were reported by laboratories. • Diagnosis – The specimen testing positive was blood (12), stool and blood (one), stool (three) and unknown (two). • Employment - No cases were reported to be in sensitive occupations. • Treatment/outcomes o Twelve of 18 cases (67 percent) were hospitalized. No deaths were reported. • Risk factors - Travel destinations for imported cases included India (eight), Pakistan (five), Mexico (two), El Salvador (one) and Philippines (one). One person reported no travel, and no source of infection could be identified.

Summary There were 18 typhoid fever cases reported in Illinois in 2006. Most cases were acquired outside the United States. India and Pakistan were the most common travel destinations for those cases who reported travel outside the United States.

Figure 105. Typhoid Fever Cases in Illinois, 2001-2006

23 25 20 18 17 18 16 18 15 10 5

Number Number of cases 0 2001 2002 2003 2004 2005 2006 Year

197 Varicella (chickenpox)

Background Chickenpox (varicella) is a highly infectious disease caused by varicella-zoster virus (VZV) and is characterized by sudden onset of slight fever and a rash. Lesions present with successive crops and several stages of maturity present at the same time. Serious complications of varicella may occur and can include pneumonia, secondary bacterial infections, hemorrhagic complications, and encephalitis. Herpes zoster (shingles) is a local manifestation of reactivation of latent varicella in dorsal root ganglia. Severe pain and paresthesia may accompany this manifestation. Fifteen percent to 30 percent of the population experience Herpes zoster (HZ) during their lifetime. can occur with debilitating pain weeks to months after resolution of HZ. Risk factors for HZ include initial infection with varicella in utero or when less than 18 months of age. Intrauterine VZV infection can result in congenital varicella syndrome, neonatal varicella or HZ during infancy or early childhood. The incubation period is 14 to 16 days after exposure to rash (range 10-21 days). A person is communicable for one to two days before rash onset and remains infectious until the rash is crusted over (usually four to seven days after rash onset). The disease is transmitted through direct contact between persons, droplet or airborne spread of vesicle fluid or respiratory tract secretions or indirectly through fomites. Secondary attack rates in households can be 90 percent. Varicella or chickenpox is a highly infectious vaccine preventable disease. Cases of varicella were reported from 33 states to CDC in 2006. In 2006, the Advisory Committee on Immunization Practices (ACIP) updated its recommendations to include a second dose of for children and catch-up vaccination for persons with no evidence of immunity. Approximately one in five vaccinated children may develop break through varicella disease if exposed to the virus. Illness is generally less severe than in unvaccinated persons. One dose of varicella vaccine is 80 percent to 85 percent effective against varicella disease. Two live attenuated vaccines are available for varicella zoster virus in the United States. One was licensed in 1995 and the other in 2005. Recommendations for varicella prevention are to: 1) Implement a two-dose varicella vaccination program for children (the first dose at 12-15 months and the second at 4-6 years) 2) Provide a second catch-up varicella vaccination for children, adolescents and adults who had previously received one dose 3) Encourage routine vaccination of all healthy persons aged greater than 13 years without evidence of immunity 4) Conduct prenatal assessment and postpartum vaccination 5) Expanding use of varicella vaccination for HIV-infected children with age- specific CD4 and T lymphocyte percentages of 15 percent to 24 percent and adolescents and adults with CD4 and T lymphocyte counts greater than 200 cells/ul 6) Establish middle school, high school and college entry,vaccination requirements

197 Illinois implemented school entry requirements for varicella vaccination in July 2002. It is required for those entering kindergarten in 2002 and for those entering first grade in 2003. Vaccination also is required in all preschools that are run by the school district and which have children aged 2 or older. In 2003, the Department also required reporting of adult chickenpox (in those older than 20 years of age) within 24 hours from the medical practice act. Permanent rules were enacted for reporting as of March 2008. This reporting was implemented because a case of smallpox in an adult might be misidentified as a case of chickenpox. The national immunization survey of Illinois children aged 19-35 months of age shows that 85 percent of children had received one or more doses of varicella vaccine at or after the child’s first birthday as compared to 89 percent nationally.

Case definition Physician diagnosed cases are reported to the Department with a weekly summary from local health jurisdictions. Only individual cases of adult varicella are reported.

Descriptive epidemiology

• Number of cases – For aggregate reporting, 1,915 cases were reported (five-year median = 6316). In adults, 134 cases were reported. Of the adult cases, 84 were classified as confirmed and 50 were probable. • Sex – Of the adult cases, 70 were female and 64 male. • Age – Adult cases ranged in age from 21 to 93 (mean = 37). • Clinical – Twenty-five adult cases were hospitalized and none were fatal. • Seasonal – Adult cases occurred in all months of the year with a slight increase in April and May. • Geographic location – Cases were residents of 31 counties. Counties reporting the most cases were Cook (46), Kane (14) and Will (12).

Summary Varicella (chickenpox) is reportable in aggregate in Illinois, and almost 2,000 cases were reported in 2006. The goal for vaccination levels is 90 percent by 2010.

Suggested readings Chaves, S.S., et. al. Varicella disease among vaccinated persons: Clinical and epidemiological characteristics, 1997-2005. JID 2008;197:S127-31. Lopez, A.S., et. al. Status of school entry requirements for varicella vaccination and vaccination coverage 11 years after implementation of the varicella vaccination program. JID 2008; 197:576-581. Marin, M. et. al. Prevention of varicella. Recommendations of the Advisory Committee on Immunization Practices (ACIP): MMWR 2007;56(RR-4):1-40. Wooten, K.G. et al. National, state and local area vaccination coverage among children aged 19-35 months-United States, 2006. MMWR 2007;56(34): 880-5.

198

Vibrio Non-cholera

Background infection causes acute diarrhea, vomiting and fever for one to three days. The incubation period usually occurs within 24 hours after eating contaminated food. Foods most often associated with this illness include raw or undercooked shellfish or other cooked foods that have been cross contaminated with raw shellfish. Vibrio spp multiply rapidly and can increase quickly if seafood is not rapidly refrigerated after harvest and kept at proper temperatures. Diagnosis is by culturing stool specimens in persons with shellfish consumption history and symptoms. The selective media, thiosulfate-citrate-bile salts-sucrose (TCBS), can be used to isolate the organism. It is estimated that 20 cases actually occur for every laboratory confirmed case reported to CDC. From 1997 through 2006, there were 4,754 Vibrio infections reported to CDC. One-quarter of cases were not foodborne. Most of these non-foodborne Vibrio infections were due to V. vulnificus, mainly in residents of the Gulf Coast states. In preliminary CDC FoodNet data the incidence was 0.34 cases per 100,000. Among 147 Vibrio isolates identified to species, 94 (64 percent) were V. parahaemolyticus and 18 (12 percent) were V. vulnificus. In 2007, all Vibrio became nationally notifiable. A cluster of V. parahaemolyticus occurred in three states in 2006 due to consumption of raw shellfish. The implicated oysters were from Washington. Prevention of Vibrio infections can include cooking shellfish thoroughly cooked to kill pathogens like V. parahaemolyticus.

Case definition A confirmed case is a clinically compatible case from which Vibrio spp. has been isolated from a clinical specimen. A probable case is a clinically compatible case that is epidemiologically linked to a confirmed case; or a clinically compatible case who consumed epidemiologically incriminated food (usually seafood) from which 1 million or more organisms per gram have been identified.

Descriptive Epidemiology - V. parahaemolyticus • Cases – Seven cases were reported in 2006. All were confirmed. • Seasonal – Cases were reported from June to September. • Race – Four of four cases with race identified were white; none were reported as Hispanic. • Sex – Eighty-six percent of cases were male. • Age – Cases ranged from 30 to 55 years of age (mean = 40). • Risk factors – Three cases reported eating raw oysters, and one reported eating raw fish. Three had an unknown source. • Outcome – One of five cases for which hospitalization data was available hospitalized. No cases were reported to be fatal. • Reporter – Four were reported by laboratories and three were reported by hospitals.

199

Descriptive epidemiology - other Vibrio species • Cases - Eight cases were reported in 2006. All were confirmed. • Seasonal – Cases were reported from March to December. • Race – Six cases were white; none were Hispanic. • Sex – Fifty percent of the cases were male. • Outcome – Hospitalization status was known for six cases and three was hospitalized. No deaths were reported. • Reporter – Five cases were reported by laboratories and three by hospitals. • Age – Cases ranged in age from 1 year to 88 years of age (mean = 43). • Geographic – Six counties reported cases including Cook (two cases), and DuPage (two cases). There was one case each in Kane, Grundy, Kankakee and Tazewell counties. • Species – Vibrio species identified in cases included Vibrio fluvialis (two), (one), Vibrio cholerae non 01 (three), Vibrio mimicus (one) and Vibrio, unknown species (one). • Individual descriptions of cases o A 29-year-old male from Grundy County who had previously received an organ transplant was diagnosed in August with V. cholerae non-O1. He had not traveled outside of Illinois. His seafood consumption history was unknown. o A 60-year-old female undergoing chemotherapy from Kankakee County was diagnosed with V. cholerae non-O1 in March. She may have consumed cooked frozen shrimp. o A 78-year-old female from Cook county was diagnosed with Vibrio, unknown type in July. No history was available. o A 1-year-old from Dupage county was diagnosed with V. fluvialis in December. Risk factors were not available. o In March, a 37-year-old female from Cook county was diagnosed with V. mimicus. Risk factors were unknown. o A Tazewell county resident was diagnosed with V. fluvialis. She was an 88-year-old female and risk factors were unknown. o A 4-year-old from Dupage county was diagnosed with V. alginolyticus in August. Risk factors were not known. o A 44-year-old from Kane County was diagnosed with V. cholera non O1 in March. The patient had traveled to the Dominican Republic and had contact with sea water and may have eaten seafood.

Suggested readings Dechet, A.M., et. al. Nonfoodborne Vibrio infections: An important cause of morbidity and mortality in the United States, 1997-2006. Clin Inf Dis 2008; 46:970-6.

200

201 Yersiniosis

Background Yersiniosis, an infrequently reported cause of diarrhea in the United States, is caused by Yersinia enterocolitica or Y. pseudotuberculosis. Transmission is by the fecal-oral route, through consumption of contaminated food or water or by contact with infected people or animals. The incubation period is three to seven days. Fecal shedding occurs for as long as symptoms are present, usually two to three weeks. Manifestations of the disease include an acute febrile diarrhea and abdominal pain. Symptoms can mimic appendicitis. Bloody diarrhea is seen in 10 percent to 30 percent of children with Y. enterocolitica. Animals are the principal reservoir for Yersinia, with the pig the primary reservoir of Y. enterocolitica; rodents are the main reservoirs for Y. pseudotuberculosis. Most pathogenic strains of Y. enterocolitica have been isolated from raw pork or pork products. Chitterling consumption or contact with someone preparing chitterlings is a common exposure history for those with yersiniosis. Yersinia is cold-tolerant and can replicate under refrigeration. Of the 10 diseases (those caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites, Yersinia comprised 158 of 17,252 (0.9 percent) of the reported infections in data from 2006. The incidence rate per 100,000 for yersiniosis in 2006 data was 0.35 (range from 0.2 to 0.5) at the nine FoodNet sites with preliminary data.

Case definition The case definition for a confirmed case in Illinois is a positive culture for Yersinia. A probable case is a case linked by epidemiology to a confirmed case but not culture positive.

Descriptive epidemiology • Number of reported cases in Illinois in 2006 - 31 (five-year median = 25) (see Figure 106). The incidence rate per 100,000 was 0.25. All were confirmed cases. • Age – Nine cases (29 percent) occurred in those younger than 1 year of age. (Figure 107). • Gender – Fifty-three percent of cases were female. • Race/ethnicity - Thirty-five percent were African American and 54 percent were white. Twenty-two percent were Hispanic. • Seasonality – Figure 108 shows the case onsets by month. Higher numbers of cases were reported in November and December. • Geographic location – Forty-four percent of cases were residents of Cook County, followed by 16 percent in St. Clair County. • Clinical history – Five of 28 (18 percent) had diarrhea; 14 of 28 (50 percent) had vomiting, and 17 of 28 (61 percent) had fever. • Outcome – For 29 cases with complete case information, 17 cases were hospitalized and no cases were reported to be fatal. • Risk factors – History of chitterling consumption was obtained for 25 cases and five cases had exposure to chitterlings. Three of the cases with chitterling exposure were

202 younger than 2 years of age. • Reporting – The most important source of reporting was infection control professionals (20 cases), followed by laboratories (eight cases).

Summary The yersiniosis incidence rate of 0.25 per 100,000 for 2006 in Illinois was similar to that found in the CDC’s FoodNet sites. Twenty-nine percent of cases in 2006 with age information occurred in children younger than a year old.

Figure 106. Yersiniosis Cases in Illinois, 2001-2006

38 40 31 28 25 25 30 22 20 10

Number of cases Numberof 0 2001 2002 2003 2004 2005 2006 Year

Figure 107. Age Distribution of Yersiniosis Cases in Illinois, 2006

10 8 6 4 2

Number of cases 0 <1 yr 1-4 yr 5-9 yr 10-19 yr 20-29 yr 30-39 yr 40-49 yr 50-59 yr >59 yr Age Group

Figure 108. Yersinia Cases in Illinois by Month, 2006

10 8 6 4 2

Number of cases Numberof 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

203 Non-foodborne, Non-waterborne Outbreaks, 2006

Case definition A non-foodborne, non-waterborne (NFNW) outbreak is an incident in which two or more persons (usually residing in separate households) experience the onset of a similar, acute illness following a common exposure (other than ingestion of common food or drink or exposure to recreational water). For NFNW outbreaks, the number ill reflects those who meet a clinical case definition. For outbreaks where the etiologic agent was suspected and not confirmed, and the clinical syndrome matched the suspect etiologic agent but no laboratory confirmation was obtained, the suspect cause is ascribed to this etiologic agent. The Department receives reports of potential NFNW outbreaks from many sources. Outbreak investigations, which are conducted by local health departments, may not result in an Illinois NFNW outbreak designation and will not be counted in the state totals.

Descriptive epidemiology The number of NFNW outbreaks reported and counted during 2006 was 121. Of the 121 NFNW outbreaks, the etiology was confirmed in 78 outbreaks, suspected in 41 outbreaks and unknown in two outbreaks. The mode of transmission was person to person (115), other (one), respiratory (one) and unknown (four). In the year 2006, a total of 4,995 people were reported to have become ill as the result of these outbreaks. The mean number of cases ill was 41 per NFNW outbreak. There were 139 persons hospitalized and three fatalities as a result of the NFNW outbreaks. A map of the NFNW outbreaks reported by county during 2006 is available in Figure 109. The 121 reported NFNW outbreaks occurred in the following months: January, three (2.5 percent); February, eight (6.7 percent); March, 14 (11.5 percent); April, 11 (9.0 percent); May, eight (6.7 percent); June, four (3.3 percent); July, three (2.5 percent); August, seven (5.8 percent); September, four (3.3 percent); October, seven (5.8 percent); November, 20 (16.5 percent); and December, 32 (26.4 percent) (Figure 110). In the 121 NFNW outbreaks reported, the etiologic agent was determined to be due to bacterial agents (infection or intoxication), either suspect or confirmed, in 11 (9 percent) (Tables 17 and 18). The bacterial pathogens were as follows: Shigella sonnei (five), Streptococcus, Group A (two), methicillin resistant S. aureus (one outbreak), S. marcescens (one), A. xylosoxidans (one) and C. difficile (one). One outbreak each was caused by histoplasmosis and cryptosporidiosis. Viral agents included norovirus (106 outbreaks). Sixty-six (62 percent) of these viral outbreaks were laboratory confirmed and 40 (38 percent) were suspect norovirus, not laboratory confirmed. Suspect norovirus outbreaks were classified largely based on symptoms, incubation and duration in the people who were affected. Although thorough investigations were conducted, there was inconclusive evidence to classify either suspect or confirm etiologic agents in two (1.6 percent) of the NFNW outbreaks and they were thus classified as etiology unknown. The site of the outbreak in NFNW outbreaks were: LTC (66 outbreaks), hospital (24), day care (nine), other elder facilities (eight), schools (six), residential facility (two)

204 and one each for college, choir camp, work site, neighborhood, convention center at hotel and house construction site. Table 19 provides an individual line listing of all 2006 NFNW outbreaks.

Figure 110. Number of Non-foodborne Non-waterborne Outbreaks by Month of First Onset, Illinois, 2006

40 Number of 30 outbreaks 20 reported 10 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

Summary

In 2006, Illinois recorded 121 NFNW outbreaks. The most common site of an outbreak was long-term care facilities. Almost 5,000 persons became ill, 139 were hospitalized and three fatalities were a consequence of these outbreaks. Outbreaks were reported from 38 counties. Viral agents were the main cause of NFNW outbreaks.

205

Table 17. Non-foodborne Non-waterborne Outbreaks, Cases, and Deaths by Etiology in Illinois, 2006 Outbreaks Cases Deaths Etiology# Count % Count % Count % Bacterial S. marcescens 1 0.8 4 0.08 0 0 C. difficile 1 0.8 3 0.06 0 0 MRSA 1 0.8 4 0.08 0 0 A. xylosoxidans 1 0.8 10 0.2 0 0 Shigella 5 4 88 2 0 0 Streptococcus, Group A 2 2 5 0.08 3 100 Total Bacterial* 11 114 3 Viral Norovirus 106 100 4791 96 0 -- Total Viral 106 4791 0 Parasites Cryptosporidiosis 1 100 17 0.34 0 -- Total Parasites 1 17 0 Fungi Histoplasmosis 1 0.8 2 0.04 0 Total Fungal 1 2 0 UNKNOWN 2 2 71 1.4 0

206

Table 18. Non-foodborne Non-waterborne Outbreak Pathogens by Testing Status in Illinois, 2006 Confirmed Suspected Unknown Etiology Count % Count % Count % Bacterial S. marcescens 1 1.2 0 - C. difficile 1 1.2 0 - MRSA 1 1.2 0 - Alcaligenes xylosoxidans 1 1.2 0 - Shigella 5 6 0 - Streptococcus, Group A 2 2.6 0 - Total Bacterial 11 0 Parasites Cryptosporidiosis 0 0 1 2 Total Parasitic 0 1 Viral Norovirus 66 85 40 98 Total Viral 66 40 Fungi Histoplasmosis 1 1.2 0 - Total Fungal 1 0 Unknown 3

207 Specific Types of NFNW Outbreaks

Bacterial Outbreaks

C. difficile Background C. difficile is a spore forming bacteria. This organism can produce two toxins (A and B). The organism can cause diarrhea and pseudomembranous colitis. Many cases have been on antimicrobials prior to onset of illness. Asymptomatic carriers are possible. The symptoms can recur after treatment. The mortality ranges from 1 percent to 2.5 percent. The incidence and severity has been increasing in the United States. Community-associated C. difficile also is being observed. Approximately one-third of cases had no prior antimicrobial use.

Case definition A confirmed C. difficile outbreak requires at least two confirmed cases with an epidemiologic link.

Descriptive epidemiology • Number of outbreaks in Illinois in 2006 – One outbreak was reported. • Individual Outbreak Descriptions o A cluster of three cases of C. difficile were reported in residents of the first floor of a long-term care facility in Cook County. Onsets ranged from December 6 through 11. Diarrhea was present in all three residents. No hospitalizations or fatalities occurred.

C. difficile Confirmed Outbreaks 1 Total number of ills 3 Average number of ills/outbreak -- Number of cases hospitalized 0 Number of fatalities 0 Outbreak months December 1 Counties of outbreaks Cook 1

Shigella Background The Shigella organism can cause person-to-person outbreaks. Symptoms include fever and diarrhea.

Case definition The case definition for an outbreak of Shigella is identification of the same serotype of the bacteria in two or more ill persons with a common epidemiologic link.

208 Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 – Five confirmed outbreaks were reported. All outbreaks were caused by S. sonnei and all occurred in day care centers. Eighty-eight persons became ill as a result of the five outbreaks and two were hospitalized. Four outbreaks took place in July and August. These five outbreaks were reported from four counties. • Individual outbreak descriptions o A cluster of two cases of S. sonnei occurred in a day care in Winnebago County. A secondary case occurred in a family member of one of the day care attendees. Three persons were culture positive. Onsets ranged from July 12 through July 21. o One day care provider, four day care attendees and one mother of a home day care attendee developed diarrheal illness in Chicago. Five of the six tested positive for S. sonnei. Onsets ranged from July 22 through August 6. Ages of the children were 1 year, 2 year, and two five-year-olds. Three cases were female and three were male. o Three attendees of a day care in Champaign developed Shigella sonnei. Onsets of illness ranged from August 23 through August 25. No children were hospitalized. Cases ranged in age from 3 to 5 years of age. There were approximately 65 attendees. o From August 7 through September 7, there were 74 persons with gastrointestinal illness at a day care in Morgan County. Eight were staff and 66 were attendees. Sixteen were confirmed Shigella sonnei cases; the rest were probable. Of the confirmed cases, 80 percent had diarrhea, 47 percent reported fever and 27 percent reported vomiting. One person was hospitalized. o Two cases of Shigella sonnei occurred in a day care in Winnebago County. Onsets were on October 31 and November 7. Both were culture positive. One was hospitalized. Both were 3 year olds. One was male and one was female. Both had diarrhea and fever and one had vomiting.

Confirmed Outbreaks 5 Total number of ills 88 Average number of ills/outbreak 18 Number of cases hospitalized 2 Number of fatalities 0 Outbreak months July 2 August 2 October 1 Counties of outbreaks Champaign 1 Cook 1 Morgan 1 Winnebago 2

209 S. aureus, Methicillin Resistant (MRSA) Background Methicillin resistant S. aureus (MRSA) can cause skin and soft tissue infections. These infections can cluster in various situations including sports teams, prisons and other locations where crowding and close contact between persons occurs.

Case definition Two or more laboratory confirmed MRSA cases with a common epidemiologic link would be needed to be considered a confirmed outbreak.

Descriptive epidemiology • Number of outbreaks reported in Illinois in 2006 – One confirmed outbreak was reported. • Number of cases – Four cases were reported as part of one outbreak. • Individual Outbreak Description o A cluster of MRSA skin and soft tissue infections occurred in four college students in Dupage County from August to October. Three tested positive for MRSA. Two were members of the college swim team and two were residents in the same residence hall. No hospitalizations or fatalities were reported.

MRSA Confirmed Outbreaks 1 Total number of ills 4 Average number of ills/outbreak - Number of cases hospitalized 0 Number of fatalities 0 Outbreak months August 1 Counties of outbreaks DuPage 1

Streptococcus, Group A Background Invasive Group A Streptococcus infection involves persons with clinically compatible illness and cultures confirmed from a sterile site. Clusters of invasive Group A Streptococcus infection can be identified in group settings, especially long-term care facilities.

Case definition For invasive Group A Streptococcus outbreaks, a confirmed outbreak requires culture confirmation of two or more cases of sterile site group A Streptococcus in persons with a common epidemiologic link. For an outbreak of non-invasive Group A Streptococcus at least 10 persons with a common epidemiologic link must be clinically

210 compatible and five test positive for Group A Streptococcus.

Descriptive epidemiology • Number of outbreaks in 2006 – Two outbreaks of invasive Group A Streptococcus were reported. Both were in long-term care facilities. Four cases were known to have been hospitalized and three fatalities were known to have occurred. • Individual outbreak descriptions o There were three cases of invasive group A streptococcus in a long-term care facility in Coles county in August. At least two cases were hospitalized and at least one was fatal. The onsets ranged from August 1 through August 11. o In December a cluster of two cases of invasive group A streptococcus were reported in residents of a long-term care facility in Chicago. Onsets of cases were December 3 through December 4. Both cases were hospitalized and fatal. The isolates were emm type 2.

Confirmed Outbreaks 2 Total number of ills 5 Average number of ills/outbreak 2.5 Number of cases hospitalized 4 Number of fatalities 3 Outbreak months August 1 December 1 Counties of outbreaks Coles 1 Cook 1

Alcaligenes xylosoxidans Background This organism has been associated with contaminated solutions like intravenous solutions, hemodialysis fluids or irrigation fluids. Bacteremia is the most commonly reported infection. It can be normal flora of the ear and gastrointestinal tract.

Case definition A confirmed outbreak would be multiple cases of A. xylosoxidans in a single facility.

Descriptive epidemiology • Number of outbreaks in 2006 – One outbreak of A. xylosoxidans was reported • Individual outbreak descriptions o There were 10 cases of A. xylosoxidans reported at a hospital in LaSalle County. Patients had fever. There was a statistically significant association with the use of morphine administered by patient controlled analgesic (PCA). There was also a statistically significant association with one particular health care worker who started or changed the patient PCA. Blood cultures were

211 collected from January 8 to July 4. No fatalities occurred. Onsets of illness were from December 25, 2005, through July 15, 2006. Ages ranged from 23 through 85 (mean=59 years). Six were female and four were male.

Confirmed Outbreaks 1 Total number of ills 10 Average number of ills/outbreak -- Number of cases hospitalized 10 Number of fatalities 0 Outbreak months January 1 Counties of outbreaks Lasalle 1

Serratia marcescens Background S. marcescens is the species of Serratia most commonly seen in human infections. This organism is common in the environment. S. marcescens can cause a wide variety of nosocomial infections. The most common site of infection is the urinary tract but it is also frequently isolated from wounds and the respiratory tract.

Case definition A confirmed outbreak would be a report of multiple cases of S. marcescens in a single facility within a short period of time.

Descriptive epidemiology • Number of outbreaks in 2006 – One outbreak of S. marcescens was reported • Individual outbreak descriptions o There were four cases of S. marcescens reported at a hospital neonatal intensive care unit in Sangamon County. Two pods were affected. In the first pod, culture was positive from eye drainage in one baby and from sputum in another baby. In the second pod, the organism was isolated from eye drainage in one baby and from blood in the other baby. Two additional babies had screening tests positive but were asymptomatic. Onsets of illness ranged from November 17, 2006, through January 12, 2007.

Confirmed Outbreaks 1 Total number of ills 4 Average number of ills/outbreak -- Number of cases hospitalized -- Number of fatalities 0 Outbreak months November 1 Counties of outbreaks Sangamon 1

212

Viral Outbreaks

Viral gastroenteritis Noroviruses are a common cause of gastroenteritis in the United States. Estimates are that 23 million people are affected by noroviruses in the United States each year. There are five genogroups (1-5). Genogroup G1 (Norwalk virus, Southampton virus and Desert shield virus), G2 (Toronota virus, Mexico virus, Hawaii virus, Bristol virus, Lordsdale virus, camberwall virus, Snow Mountain agent and Melksham virus) and genogroup G4 infect humans, genogroup G3 has been found in cattle and genogroup G5 has been identified in mice. Sapoviruses have only been identified in humans, especially children. Noroviruses are transmitted through consumption of contaminated food or water, directly from person to person and from airborne droplets produced during vomiting. The most common method of spread is via the fecal-oral route. The virus is excreted in stool and vomitus for up to 10 days. The incubation period and duration of illness ranges from 24 to 48 hours. Duration of illness ranges from 12 to 60 hours. Virus shedding peaks 25 to 72 hours after exposure to the virus. Within 48 to 72 hours after symptom onset, virus concentration in the stool declines below levels detectable by electron microscopy. Short-term immunity occurs after infection. Vomiting, diarrhea, headache and body aches are commonly reported. Humans are the only known reservoir for these viruses. Characteristics of the virus that facilitate spread include low infectious dose, high concentration of virus in stool, strain diversity, environmental stability and prolonged shedding. Illness caused by norovirus can be suspected based on incubation period, duration of illness, symptoms or by identification of the organism in stool. Noroviruses can survive freezing and temperatures of up to 60 C and can survive chlorine levels up to 10 ppm (that exceeds what is normally present in public water systems). Outbreaks are not uncommon in closed settings, such as detention facilities, cruise ships, long-term care facilities and hospitals. The virus cannot be grown in cell culture; a polymerase chain reaction (PCR) test is used to diagnose norovirus. Testing for viral gastroenteritis in humans is not useful for screening individual samples but is useful when multiple samples are available in an outbreak. Norovirus can be present in stools for up to a week after illness onset. Immunity is short-lived and appears to be strain specific. Since there are so many strains, individuals can be repeatedly infected by noroviruses during their lifetime.

Case definition Several laboratory tests may help to confirm an outbreak related to norovirus. These include positive results on RT-PCR, visualization of small round structured virus (SRSV) in electron microscopy of stool from ill individuals, or a fourfold rise in antibody titer to norovirus seen in acute and convalescent sera in most serum pairs. Multiple samples are needed from each outbreak to provide sufficient specimens to verify the causative agent as norovirus. An outbreak is considered confirmed when at least two ill persons have positive laboratory results and have a common epidemiologic link. A suspect outbreak can be identified in persons who have a clinically compatible illness

213 (diarrhea and vomiting) and a short duration of illness with few hospitalizations and less than three persons testing negative for norovirus and less than two patients testing positive for the pathogen.

Descriptive epidemiology Number of outbreaks reported in Illinois in 2006 – Forty suspected outbreaks of norovirus gastroenteritis, based on clinical syndrome, incubation period and duration of illness and 66 laboratory confirmed outbreaks were reported. Confirmed norovirus outbreaks affected 3,111 people who experienced compatible illness (mean = 47 ill persons per outbreak; range four to 228). Suspect norovirus outbreaks affected 1,680 persons (mean = 42; range: three to 162). The 66 confirmed norovirus outbreaks occurred in the counties of Adams (one), Bureau (one), Champaign (one), Cook (24), DeKalb (one), Dupage (two), Fulton (1), Grundy (one), Kane (two), Lawrence (one), Livingston (one), Macon (two), Macoupin (two), Madison (three), Marion (2), Massac (one), Morgan (four), Moultrie (one), Richland (one), Rock Island (one), Sangamon (two), St Clair (one), Whiteside (four), Will (one), Williamson (one) and Winnebago (four). Genotyping information was available on 63 confirmed outbreaks and nine suspect outbreaks. Two were G1 (one confirmed and one suspect outbreak), 67 were G2 (59 confirmed and eight suspect outbreaks) and three were both G1 and G2 (3 confirmed). Confirmed outbreaks resulted in 79 hospitalizations and no fatalities. Suspect norovirus outbreaks resulted in 19 hospitalizations and no fatalities. The sites of confirmed outbreaks were long-term care facilities (41), hospital (19), day care (two) and one each for assisted living, choir camp, a multiple type of senior living facility and residential facilities. Suspect norovirus outbreaks occurred in long-term care facilities (24), school (five), assisted living (three), retirement community (three), day care (two) and one each for hospital, hotel convention center and developmentally delayed facility. The number of days of duration of the outbreak at the facilities were 14 for confirmed outbreaks and 11 days for the suspected outbreaks.

• Individual descriptions of confirmed outbreaks

o Nineteen persons (18 residents, one staff) developed gastrointestinal illness at a long-term care facility in DuPage County in January. Two of three persons tested were positive for norovirus G2. Onsets of illness were from January 29 through February 2. Three persons were hospitalized and there were no fatalities. All persons reported diarrhea. o In January, 15 persons (8 residents and 7 staff) were affected by norovirus in a long-term care facility in Winnebago County. There were 80 residents at the facility. Onsets ranged from January 14 through February 1. o In February, 21 persons (19 residents, 2 staff) at a long-term care facility in Joliet were reported with gastrointestinal illness. Four of five specimens tested positive for norovirus G2. It is unknown if anyone was hospitalized. o Sixty-eight persons (25 staff, 43 residents) at a LTC facility in Kane County reported gastrointestinal illness in February. Illness onsets ranged from February 19 to February 27. One stool was positive for G1 and one

214 for G1 and G2. Five residents were sent to the hospital but it is unknown if they were hospitalized. o In February, 25 staff and 63 residents were affected with gastrointestinal illness at a long-term care facility in Grundy County. Sixty percent had diarrhea and 45 percent had vomiting. Five persons were hospitalized. Three of three stool specimens were positive for norovirus G2. Onsets ranged from February 25 through March 4. o A hospital in Kane County reported 43 persons (4 visitors, 18 staff and 21 patients) with gastrointestinal illness. These illnesses occurred after several residents of a LTC facility had been treated in the ED or admitted to the hospital between February 27 and 28. Illnesses at the hospital ranged from March 2 through March 7. Five of seven specimens were positive for Norovirus G2. o In March, 19 illnesses (1 staff, 18 residents) occurred in a long-term care facility in Skokie, Illinois. Illnesses ranged from March 5 through March 8. Twelve of 20 stools tested positive for norovirus G2. Five persons were hospitalized; there were no fatalities. o Eighteen (17 residents, 1 staff) persons from a long-term care facility in Skokie, Illinois were reported with gastrointestinal illness in March. Illness onsets ranged from March 2 through March 8. No persons were hospitalized. Four of seven persons were tested positive for norovirus G2. o Thirteen staff and five patients at a Cook County hospital experienced diarrhea and/or vomiting in March. Three of three persons tested positive for norovirus G2. o Five persons were confirmed with norovirus G2 at a hospital in Chicago. No information is available on the total number ill. Illnesses began around March 15. o A hospital in Cook County reported 228 persons (100 staff and 128 residents) ill with norovirus G2. Onsets began on March 18 and ended on April 14. o A long-term care facility in Cook County reported 99 persons ill (75 residents, 25 staff) with norovirus G2 in March. Onsets began on March 6 and continued through April 5. Eight of eight stools tested positive for norovirus. Six persons were hospitalized. Fifty percent reported diarrhea and 32 percent reported vomiting. o In March, a long-term care facility in Cook County reported 29 persons ill (12 staff, 17 residents) with norovirus G2. Two of three tested were positive for norovirus G2. Three residents were hospitalized. Onsets ranged from March 13 through April 7. Eighty-six percent had diarrhea and 59 percent reported vomiting. o There were 101 persons (19 staff, 82 residents) reported ill with norovirus G2 in a hospital in Cook County in March. Onset dates ranged from March 29 through April 12. Twenty-two of 36 stool specimens from ill persons tested positive for norovirus G2. There were no fatalities. o Thirty-three persons (29 residents, four staff) were reported with gastrointestinal illness at a long-term care facility in Cook County in

215 March. Onsets ranged from March 25 through March 31. Three of three stools tested were positive for norovirus. No hospitalizations were reported. o A hospital in Cook County reported 91 illnesses (66 staff, 25 patients) in April. Three of three stools tested were positive for norovirus G2. Onsets occurred from April 3 through April 27. o Four residents at a long-term care facility in Cook County were affected by norovirus G2. Three of three stools tested positive. There were an unknown number of hospitalizations. o In April, 95 persons (38 staff, 57 residents) were reported with gastrointestinal illness in a long-term care facility in Cook County. Three of three stools were positive for norovirus G2. There were no hospitalizations. o At least 13 persons were affected with gastrointestinal illness at a long- term care facility in Cook County. Seven of 13 stools tested positive for norovirus G2. No hospitalizations were reported. o In April, an estimated 119 persons were ill with gastrointestinal illness in a Chicago long-term care facility. Forty-one staff and 78 residents were reported to be ill. Five persons tested positive for norovirus G2. Five persons were hospitalized. o Twenty-two persons (11 staff, 11 patients) at a hospital in Chicago developed gastrointestinal illness in April. Illness onsets ranged from April 29 through May 7. Norovirus G2 was identified in nine of 10 stool specimens. o From April 15 to May 4, 37 persons (nine staff, 28 residents) developed gastrointestinal illness in an assisted living facility in DeKalb County. There were 101 exposed individuals. Five persons tested positive for norovirus G2. Fifteen were hospitalized. o Twenty persons (3 staff, 17 residents) experienced diarrhea at a long-term care facility in Winnebago County in May. Six of 12 stools tested positive for norovirus G2. Onsets of illness ranged from May 1 through May 8. All ill persons had diarrhea and 11 percent experienced vomiting. o Five patients in the skilled nursing unit at a hospital developed norovirus G2 in May in Adams County. Three of five stool specimens tested positive. Onsets of illness ranged from May 8 through May 10. o Twelve persons attending a party at a LTC facility in Rock Island developed gastrointestinal illness in May 2006. Illness onsets ranged from May 7 to May 8. Illnesses had started before the party and transmission was believed to be person-to-person. Some of the ill persons were visitors, some staff and some were residents. One person was hospitalized. Two stools were positive for G2 and two were weakly positive for G1 and five were tested. o In May, four persons tested positive for norovirus at a hospital in Sangamon County. Illness onsets ranged from May 9 through May 16. Thirty six persons (19 staff and 17 residents) became ill.

216 o Sixty persons (20 staff and 40 residents) of a long-term care facility in Winnebago County developed diarrhea and/or vomiting. Three of three tested positive for norovirus G2. Onsets of illness ranged from May 17 through May 25. One person was hospitalized. o Thirteen residents of a long-term care facility in Winnebago County reported gastrointestinal illness in May. Onsets of illness continued from May 23 through May 24. No hospitalizations were reported. Five of five stools tested positive for norovirus. o In June, 42 persons (17 staff and 23 residents) of a long-term care facility in Whiteside County developed gastrointestinal illness. Five of five stools tested positive for norovirus G2. Onsets ranged from June 9 through June 16. Seventy-four percent reported diarrhea and 57 percent vomiting. The number of hospitalizations was unknown. o There were 118 of 700 show choir participants who became ill in June in Macon County. Five of five tested positive for norovirus G2. Onsets of illness ranged from June 19 through June 24. No hospitalizations were reported. o In August, 43 persons (nine staff and 34 residents) were ill with gastrointestinal illness in a long-term care facility in Lawrence County. Five of eight tested positive for norovirus G2. Eighty-eight percent of the ill persons experienced diarrhea and 35 percent had vomiting. No hospitalizations were reported. o Forty-eight persons (18 staff, 30 residents) of a long-term care facility in Massac County reported gastrointestinal illness between September 14 and September 27. Three of five stools tested positive for norovirus G2. There were 180 persons exposed. No hospitalizations were reported. o In September, 38 persons (14 staff, 24 residents) in a long-term care facility in Madison County developed diarrhea and/or vomiting. Five of five stools tested positive for norovirus G2. Four ill persons were hospitalized. All had diarrhea and 50 percent reported vomiting. Onsets of illness ranged from September 28 through October 28. o Gastrointestinal illnesses started on August 15 in a long-term care facility in Marion County. Twenty staff and residents were ill. Two of four tested positive for norovirus G2. The number of hospitalizations was unknown. o Ninety-nine persons (26 staff, 73 residents) became ill at a Morgan County long-term care facility in October. Two of three stools tested positive for norovirus G2. Onsets ranged from October 2 through October 31. No hospitalizations were reported. o In October, a norovirus G2 outbreak occurred in a long-term care facility in Fulton County. Seventy-four persons (27 staff, 47 residents) were affected. Onsets of illness ranged from October 24 through October 31. Four of six stools tested were positive for norovirus G2. All cases reported vomiting and 75 percent reporting diarrhea. One person was hospitalized. o Hospital staff (28) and patients (eight) developed gastrointestinal illness from October 20 through November 1 in a hospital in Marion County. Five

217 of five stools tested positive for norovirus G2. A patient was initially admitted with diarrhea and vomiting. o In October there were 40 persons, including staff, attendees and household members of attendees) of 118 exposed individuals who developed gastrointestinal illness in a Morgan County day care. Two of four stools tested positive for norovirus G2. Illness onsets ranged from October 19 through November 13. No hospitalizations were reported. o A total of 47 persons (26 staff, 21 residents) became ill at a long-term care facility in St Clair County in October. Eight of nine stools were positive for norovirus G2. Onsets of illness ranged from October 24 through October 30. No hospitalizations or fatalities were reported. o From October 30 through November 9, 58 (30 staff, 28 residents) were ill with gastrointestinal illness at a long-term care facility in Whiteside County. Three of five stools tested were positive for norovirus G2. Cases reported diarrhea (82 percent) and vomiting (71 percent). Three persons were hospitalized. o In November, 129 of 178 exposed persons at a long-term care facility in Moultrie county developed gastrointestinal illness. Three of three stools were positive for norovirus G2. Fifty-four staff and 75 residents became ill between November 1 and November 20. No hospitalizations or fatalities were reported. o In November, a norovirus G2 outbreak was reported in Morgan County. Five staff and 25 attendees or their families reported gastrointestinal illness. There were 110 exposed persons at the day care. Two of five stools were positive for norovirus G2. No hospitalizations or fatalities occurred. Onsets of illness ranged from November 8 through November 20. o At a hospital in Cook County in November, 13 persons (3 staff, 10 patients) became ill with gastrointestinal disease. Four of 10 persons tested positive for norovirus G2. o Five persons (one staff, four patients) were ill from November 8 through November 14 at a hospital transitional care unit in Morgan County. Two of two stools tested positive for norovirus G2. All persons had both diarrhea and vomiting. o Fifty-nine of 160 exposed persons at a hospital in Macoupin County developed gastrointestinal illness. Four of five tested were positive for norovirus G2. Onsets of illness ranged from November 12 through December 8. o From November 21 through December 14, 21 persons (15 staff, six residents) at a Sangamon County hospital developed gastrointestinal illness. Five of eight persons tested positive for norovirus G2. o In a Cook County hospital, 88 persons (72 staff, 16 patients) became ill with gastrointestinal illness in November. Eleven of 15 persons tested positive for norovirus G2.

218 o From November 29 through December 17, 126 persons (35 staff, 91 residents) became ill with gastrointestinal illness in a Madison County long-term care facility. Two of three stools were positive for norovirus G2. o Twenty-two individuals (12 staff, 10 residents) developed gastrointestinal illness at an assisted living facility in Williamson County in November. Two of three stools were positive for norovirus G2. Six persons were hospitalized. Illness onsets ranged from November 30 through December 6. o From November 26 through December 14, 23 persons (10 staff, 13 residents) from a long-term care facility in Champaign County were affected with norovirus. Three of three stools tested positive for norovirus G2. Sixty-two percent reported vomiting and 81 percent reported diarrhea. No hospitalizations were reported. o In December, five of five stools submitted from a long-term care facility in Bureau County tested positive for norovirus G2. Sixty-six (30 staff, 36 residents) of 124 exposed persons developed gastrointestinal illness. One person was hospitalized. o Thirty-three persons (17 staff, 16 patients) at a hospital long-term care unit in Richland County were affected by gastrointestinal illness. Illness onsets ranged from December 1 through December 8. Sixty-three percent reported vomiting and 88 percent diarrhea. Three of four tested positive for norovirus G1. No hospitalizations were reported. o In December, 24 (four staff, 20 residents) of a long-term care facility in Livingston County developed diarrhea and/or vomiting. Four of four persons tested positive for norovirus G2. Illness onsets ranged from December 3 through December 6. No hospitalizations were reported. o From December 2 through December 12, 14 persons (four staff, 10 residents) were ill with gastrointestinal illness at a Chicago long-term care facility. Four of five tested positive for norovirus G2. No hospitalizations were reported. o In DuPage County, 21 persons (six staff, 15 residents) reported gastrointestinal illness at a hospital long-term care facility. Eight of eight persons tested positive for norovirus G2. Symptoms included vomiting (57 percent) and diarrhea (81 percent). One person was hospitalized and no fatalities were reported. Illness onsets ranged from December 3 through December 19. o From December 9 through December 14, 17 persons (two staff, 15 residents) at a Chicago hospital developed gastrointestinal illness. Seven of seven persons tested positive for norovirus G2. o Six of seven stools tested positive for norovirus G2 in an outbreak involving staff at a hospital in Whiteside. From December 3 through January 11, 76 staff became ill. None were hospitalized. o A Chicago long-term care facility reported an outbreak of norovirus G2 from December 1 through December 25. Four of six persons tested positive. Four persons were hospitalized. Twenty-six persons (nine staff, 17 residents) became ill.

219 o In December, 45 persons (23 staff, 22 patients) of a hospital in Whiteside County developed gastrointestinal illness. Two of two tested positive for norovirus G2. There were 172 persons exposed. Seventeen of the ill were in the long-term care area. Onsets of illness ranged from December 2 through December 21. The number of hospitalizations were unknown. o Forty-three persons (16 staff, 27 residents) became ill at a long-term care facility in Macoupin County. Eight of nine tested positive for norovirus G2. Ninety-five percent reported diarrhea and 98 percent vomiting. Onsets of illness ranged from December 3 through December 19. No hospitalizations were reported. o From December 11 through December 19, 38 persons (five staff, 33 residents) were identified with gastrointestinal illness at a long-term care facility in Macon County. Two of seven persons tested positive for norovirus G2. Two persons were hospitalized. o Eighteen staff at a hospital in Chicago in December reported gastrointestinal illness. Two of two tested positive for norovirus G1 and G2. None were hospitalized and no fatalities were reported. Onsets of illness ranged from December 12 through December 18. o In December, 58 persons (8 staff, 50 residents) of an assisted living and independent living facility became ill. Two tested positive for norovirus. Nine were hospitalized and there were no reported fatalities. Onsets of illness ranged from December 7 through 30. Ninety-one percent reported diarrhea and 74 percent reported vomiting. o From December 18 through December 27, 48 persons (17 staff, 31 residents) of a long-term care facility in Madison County were reported with gastrointestinal illness. None were hospitalized and none were fatal. Three of five persons tested positive for norovirus G2. o A Chicago long-term care facility reported illness in 42 persons (13 staff, 29 residents) from December 30, 2006 through January 9, 2007. Five of five persons tested positive for norovirus G2. Two persons were hospitalized. o From December 21, 2006, through January 12, 2007, 32 gastrointestinal illnesses were reported in persons at a long-term care facility in Cook County. Eight of 16 tested positive for norovirus G2. Fifteen were staff members and 17 were residents. Three were hospitalized and no fatalities were reported.

Norovirus Confirmed Suspected* Outbreaks 66 40 Total number of ills 3,111 1,680 Average number of ills/outbreak Number of cases hospitalized 79 42 Number of fatalities 0 0 Outbreak months January 2 0

220 February 3 5 March 10 3 April 7 4 May 6 2 June 2 1 July 0 1 August 2 0 September 2 1 October 6 0 November 10 9 December 16 14 Counties of outbreaks Adams 1 0 Bureau 1 1 Champaign 1 0 Cook 24 7 DeKalb 1 0 DuPage 2 4 Ford 0 1 Fulton 1 0 Grundy 1 0 Jo Daviess 0 4 Kane 2 4 Lake 0 2 Lawrence 1 1 Livingston 1 0 Macon 2 1 Macoupin 2 0 Madison 3 0 Marion 2 0 Massac 1 0 McHenry 0 1 McLean 0 1 Montgomery 0 2 Morgan 4 1 Moultrie 1 0 Ogle 0 1 Richland 1 0 Rock Island 1 0 St Clair 1 0 Saline 0 1 Sangamon 2 3 Schuyler 0 1 Tazewell 0 1 Williamson 1 0 Whiteside 4 0 Will 1 1 Wlliamson 1 0 Winnebago 4 2

221

Facility Type Long-term care 41 24 Hospital 19 1 Retirement facility 0 3 Day care 2 2 Hotel 0 1 School 0 5 Show choir camp 1 0 Assisted living 1 3 DD facility 0 1 Residential facility 1 0 Assisted living and independent living 1 0

Parasites

Cryptosporidiosis Background Outbreaks of cryptosporidiosis are typically associated with recreational or drinking water exposure or day care centers. Transmission can be fecal-oral, animal to person, waterborne and foodborne.

Descriptive epidemiology • Number of outbreaks in 2006 – One outbreak was reported. • Individual outbreak descriptions One outbreak of suspect cryptosporidiosis was reported in a community in Jo Daviess County in June. Seventeen people from five households on the same street became ill. One tested positive for cryptosporidiosis of five tested. The source was unknown. Onsets of illness ranged from June 9 through August 15.

Suspected Outbreaks 1 Total number of ills 17 Average number of ills/outbreak - Number of cases hospitalized 0 Number of fatalities 0 Outbreak months June 1 Counties of outbreaks Jo Daviess 1

Fungi

Histoplasmosis Background Outbreaks of histoplasmosis have been identified previously in Illinois and are most commonly associated with occupational exposures, such as bridge repair or earth moving activities.

222

Descriptive epidemiology • Number of outbreaks in 2006 – One outbreak was reported. • Individual outbreak descriptions An outbreak of histoplasmosis occurred in September in two male Chicago residents of six persons who traveled to Kentucky to repair a home. They had contact with bird droppings. The case ages were 19 and 46. Both persons were hospitalized and survived. Confirmed Outbreaks 1 Total number of ills 2 Average number of ills/outbreak - Number of cases hospitalized 2 Number of fatalities 0 Outbreak months September 1 Counties of outbreaks Cook 1

Unknown Descriptive Epidemiology • Number of outbreaks in 2006 – Three outbreaks with unknown etiology were reported in 2006. • Individual outbreak descriptions A cluster of 66 cases of gastrointestinal illnesses occurred in a school in LaSalle County. A cluster of five persons became ill at a work site in Adams County in August. Onsets of diarrhea ranged from August 31 through September 6. Two persons tested negative for norovirus.

Unknown Outbreaks 2 Total number of ills 71 Average number of ills/outbreak 35 Number of cases hospitalized 0 Number of fatalities 0 Outbreak months March 1 August 1 Counties of outbreaks Adams 1 LaSalle 1

223 Figure 109. Number of Non-foodborne, Non-waterborne Outbreaks Reported in Each Illinois County, 2006

Jo DaviessStephensonWinnebago McHenry Lake 5 0 8 1 2 Boone Carroll Ogle 0 0 1 Kane DeKalb 6 DuPageCook 1 Whiteside Lee 7 34 4 0 Kendall 0 Rock Island Will Henry Bureau 2 1 2 La Salle 0 2 Grundy Mercer Putnam 1 0 0 Kankakee Stark 0 0 Marshall Knox 0 Livingston Warren 0 Henderson Peoria 1 0 0 Woodford Iroquois 0 0 1 McDonough Ford 0 McLean 1 Fulton Hancock Tazewell 1 0 1 1 Mason Schuyler De Witt ChampaignVermilion 0 Logan 1 0 2 0 Menard 0 Piatt Adams Brown Cass 2 0 0 0 0 Macon Morgan Sangamon 3 Douglas 6 6 0 Edgar Pike Scott Moultrie 0 0 0 Christian 1 Coles 0 Shelby 1 Greene 0 Clark 0 Macoupin Cumberland 0 Calhoun 2 Montgomery 0 0 Jersey 2 Effingham Jasper Crawford 0 Fayette 0 0 0 Bond 0 Madison 0 Clay 3 RichlandLawrence 0 Clinton Marion 1 2 0 2 St. Clair Wayne Wabash 1 Washington 0 0 Jefferson Monroe 0 Edwards 0 0 0 Randolph Perry White 0 0 Franklin 0 0 Jackson 0 SalineGallatin Williamson 1 0 1 Hardin Union 0 0 Pope Johnson 0 Pulaski 0 Massac 0 1 Alexander 0

224 Table 19. Non-foodborne and Non-waterborne Outbreaks in Illinois in 2006.

Exposure # lab # Staff/ # IDPH Log positive First Exp Residents Symptoms Transmission Location of Number Onset Last Onset City County ILL/Exp or Students * Type Agent Implicated Status outbreak

Possibly thru Alcaligenes IL2006-90 10 1/1 7/1 Ottawa LaSalle 10/unk 0/10 F medication drip xylosoxidans C Hospital 3

IL2006-52 1/14 2/1 Rockford Winnebago 15/80 7/8 D,V Person-person Norovirus C LTC 1

IL2006-10 1/21 2/2 Naperville Dupage 19/149 1/18 D Person-person Norovirus G2 C LTC 0

IL2006-53 2/4 2/15 Cicero Cook 59/unk D,V Person-person Norovirus S LTC 0

IL2006-54 2/8 2/14 Plainfield Will 35/unk D,V Person-person Norovirus S LTC 0

IL2006-55 2/10 2/14 Palos Heights Cook 60/unk D,V Person-person Norovirus S LTC 0 2/13 IL2006-11 est Cook 13/unk 0/13 D,V Person-person Norovirus G2 S LTC 2 Norovirus G1 & IL2006-14 2/19 2/27 Elgin Kane 68/139 25/43 D,V Person-person G2 C LTC 0

IL2006-16 2/20 2/24 Lisle DuPage 57/81 20/37 D,V Person-person Norovirus S LTC 4

IL2006-13 2/22 Joliet Will 21/unk 2/19 D,V Person-person Norovirus G2 C LTC 3

IL2006-15 2/25 3 / 4 Morris Grundy 88/104 25/63 D,V Person-person Norovirus G2 C LTC 0

IL2006-18 3/1 3/2 Lostant LaSalle 66/96 5/61 D,V Person-person Unknown U School

225 5 18/21, 4 IL2006-19 3/2 3/7 Elgin Kane 43/unk visitors D,V Person-person Norovirus G2 C Hospital 4

IL2006-21 3/2 3/8 Skokie Cook 18/102 1/17 D,V Person-person Norovirus G2 C LTC 1

IL2006-44 3/3 4/4 Evanston Cook 25/unk 5/20 D,V Person-person Norovirus G2 S LTC 12

IL2006-20 3/5 3/8 Skokie Cook 19/84 1/18 D,V Person-person Norovirus G2 C LTC 3

IL2006-23 3/6 Oak Lawn Cook 18/unk 13/5 D,V Person-person Norovirus G2 C Hospital 7

IL2006-31 3/6 4/5 Evanston Cook 99/455 24/75 D,V Person-person Norovirus G2 C LTC 0 Retirement IL2006-29 3/11 East Dundee Kane 30/unk 0/30 D,V Person-person Norovirus S community 2

IL2006-36 3/13 4/7 Evanston Cook 29/157 12/17 D,V Person-person Norovirus G2 C LTC 5

IL2006-24 3/15 Chicago Cook 5/unk D,V Person-person Norovirus G2 C Hospital 22

IL2006-28 3/18 4/14 Park Ridge Cook 228/unk 100/128 D,V Person-person Norovirus G2 C Hospital 1 11/38, 1 IL1006-32 3/22 3/31 St Charles Kane 51/82 visitor D,V Person-person Norovirus G2 S LTC 3

IL2006-41 3/25 3/31 Skokie Cook 33/unk 4/29 D,V Person-person Norovirus G2 C LTC 22 Arlington IL2006-37 3/29 4/12 Heights Cook 101/unk 19/82 D,V Person-person Norovirus G2 C Hospital 2

IL2006-48 4/3 4/27 Oak Forest Cook 91/unk 66/25 D,V Person-person Norovirus G2 C Hospital

226 0

IL2006-46 4/5 4/11 Rockford Winnebago 42/120 1/41 D,V Person-person Norovirus S LTC 7

IL2006-58 4/10 Desplaines Cook 13/unk D,V Person-person Norovirus G2 C LTC 5

IL2006-59 4/11 5/16 Chicago Cook 119/120 41/78 D,V Person-person Norovirus G2 C LTC 1

IL2006-51 4/14 4/15 Evanston Cook 3/unk 0/3 D,V Person-person Norovirus G2 S Day care 5 Residential IL2006-62 4/15 5/4 Dekalb 37/101 9/28 D,V Person-person Norovirus G2 C facility 3

IL2006-49 4/18 Des Plaines Cook 4/unk 0/4 D,V Person-person Norovirus G2 C LTC 0

IL2006-56 4/18 4/25 Geneva Kane 40/unk 14/26 D,V Person-person Norovirus S LTC 3

IL2006-57 4/23 South Holland Cook 95/unk 38/57 D,V Person-person Norovirus G2 C LTC 0 Retirement IL2006-60 4/25 Niles Cook 12/unk Unk/12 D,V Person-person Norovirus S facility 9

IL2006-63 4/29 5/7 Chicago Cook 22/unk 11/11 D,V Person-person Norovirus G2 C Hospital 6

IL2006-67 5/1 5/8 Winnebago 20/382 3/17 D Person-person Norovirus G2 C LTC 0 Hotel IL2006-72 5/5 5/16 Springfield Sangamon 30/350 D,V Person-person Norovirus S convention 2

IL2006-69 5/7 5/8 Rock Island Rock Island 12/42 D,V Person-person Norovirus G1&G2 C LTC 3

IL2006-68 5/8 5/10 Quincy Adams 5/unk 0/5 D,F,V Person-person Norovirus G2 C Hospital

227 4

IL2006-70 5/9 5/16 Springfield Sangamon 36/50 19/17 D,V Person-person Norovirus C Hospital 3

IL2006-73 5/17 5/25 Durand Winnebago 60/70 20/40 D,V Person-person Norovirus G2 C LTC 5

IL2006-76 5/23 5/24 Rockford Winnebago 13/73 0/13 D,V Person-person Norovirus G2 C LTC 0

IL2006-75 5/24 Elgin Kane 27/186 1/26 D,V Person-person Norovirus S School 1

IL2006-108 6/9 8/15 Galena JoDaviess 17/19 D Unknown Cryptosporidiosis S Neighborhood 5

IL2006-80 6/9 6/16 Prophetstown Whiteside 42/64 17/23 D,V Person-person Norovirus G2 C LTC 0

IL2006-79 6/10 Springfield Sangamon 8/unk D,V Person-person Norovirus S Hospital 5

IL2006-85 6/19 6/24 Decatur Macon 118/700 D,V Person-person Norovirus G2 C Choir camp 2

IL2006-93 7/12 7/21 Rockford Winnebago 3/unk 0/3 D Person-person S. sonnei C Day care 6

IL2006-102 7/22 8/6 Chicago Cook 6/12 1/5 D Person-person S. sonnei C Day care 1

IL2006-95 7/26 7/31 Decatur Macon 14/unk 2/12 D,V Person-person Norovirus G2 S Assisted living 3

IL2006-104 8/1 Charleston Coles 3/unk 0/3 Invasive Unknown S. pyogenes C LTC 3

IL2006-200 8/1 10/28 Wheaton Dupage 4/unk 0/4 SSTI Person-person MRSA C College 2

IL2006-110 8/7 9/7 Jacksonville Morgan 74/146 8/66 D,F Person-person S. sonnei C Day care

228 2

IL2006-107 8/15 Marion Marion 20/unk D,V Person-person Norovirus G2 C LTC 3

IL2006-116 8/23 8/25 Champaign Champaign 3/50 0/3 D Person-person S. sonnei C Day care 5

IL2006-114 8/25 8/31 Bridgeport Lawrence 43/unk 9/34 D,V Person-person Norovirus G2 C LTC 0

IL2006-115 8/31 9/6 Camp Point Adams 5/unk 5/0 D Unknown Unknown U Work site F, 2 Chicago shortness Histoplasma House IL2006-125 9/12 9/23 residents Out-of-state 2/6 of breath Inhalation capsulatum C construction 0

IL2006-119 9/14 9/17 Bureau 17/unk 0/17 D,V Person-person Norovirus S LTC 3

IL2006-120 9/14 9/27 Metropolis Massac 48/180 18/30 D,V Person-person Norovirus G2 C LTC 5

IL2006-123 9/28 10/28 Alton Madison 38/unk 14/24 D,V Person-person Norovirus G2 C LTC 2

IL2006-127 10/2 10/31 Jacksonville Morgan 99/331 26/73 D,V Person-person Norovirus G2 C LTC 2 9/25, 3 IL2006-131 10/19 11/13 Jacksonville Morgan 40/118 other D,V Person-person Norovirus G2 C Day care 5

IL2006-128 10/20 11/1 Salem Marion 36/unk 28/8 D,V Person-person Norovirus G2 C Hospital 8

IL2006-132 10/24 10/30 Belleville St Clair 47/unk 26/21 D,V Person-person Norovirus G2 C LTC 4

IL2006-130 10/24 10/31 Canton Fulton 74/225 27/47 D,V Person-person Norovirus G2 C LTC 3

IL2006-137 10/30 11/9 Morrison Whiteside 58/126 30/28 D,V Person-person Norovirus G2 C LTC

229 2

IL2006-145 10/31 11/7 Rockford Winnebago 2/unk 0/2 D,F,V Person-person Shigella sonnei C Day care 3

IL2006-136 11/1 11/20 Sullivan Moultrie 129/178 54/75 D,V Person-person Norovirus G2 C LTC 0

IL2006-204 11/8 11/26 Elizabeth Jo Daviess 13/115 13/0 D,V Person-person Norovirus S LTC 2

IL2006-142 11/8 11/14 Jacksonville Morgan 5/unk 1 / 4 D,V Person-person Norovirus G2 C Hospital 2

IL2006-139 11/8 11/20 Jacksonville Morgan 30/110 D,V Person-person Norovirus G2 C Day care 0

IL2006-146 11/12 Jacksonville Morgan 10/103 2/8 D,V Person-person Norovirus S Day care 4

IL2006-143 11/12 12/8 Carlinville Macoupin 59/160 55/4 D,V Person-person Norovirus G2 C Hospital 4

IL2006-140 11/12 Park Ridge Cook 13/unk 3/10 D,V Person-person Norovirus G2 C Hospital 0

IL2006-144 11/13 11/21 Roselle DuPage 106/unk D,V Person-person Norovirus S School 4 Eye drainage, bloodstrea m infection, Serratia IL2006-209 11/17 1/12 Springfield Sangamon 4/unk 0/4 sputum Unknown marcescens C Hospital, NICU 11

IL2006-152 11/19 Chicago Cook 88/unk 72/16 D,V Person-person Norovirus G2 C Hospital 0

IL2006-157 11/20 12/1 Hopedale Tazewell 42/80 18/24 D,V Person-person Norovirus S LTC 5

IL2006-147 11/21 12/14 Springfield Sangamon 21/123 15/6 D,V Person-person Norovirus G2 C Hospital

230 0

IL2006-148 11/22 11/28 Auburn Sangamon 19/102 4/15 D,V Person-person Norovirus S LTC 3

IL2006-161 11/26 12/14 Champaign Champaign 23/210 10/13 D,V Person-person Norovirus G2 C LTC 0

IL2006-205 11/27 1/25 Warren JoDaviess 162/578 3/159 D,V Person-person Norovirus S School 0

IL2006-167 11/27 Waukegan Lake 30/210 9/21 D Person-person Norovirus S DD facility 1

IL2006-155 11/27 11/30 Lawrenceville Lawrence 45/unk 18/27 D,V Person-person Norovirus S LTC 1

IL2006-166 11/27 12/8 Eldorado Saline 67/120 18/49 D,V Person-person Norovirus G2 S LTC 2

IL2006-171 11/29 12/17 Alton Madison 126/unk 35/91 D,V Person-person Norovirus G2 C LTC 2

IL2006-158 11/30 12/6 Herrin Williamson 22/80 12/10 D,V Person-person Norovirus G2 C Assisted living 1

IL2006-165 12/1 Park Ridge Cook 63/unk 17/46 D,V Person-person Norovirus G2 S Assisted living 3

IL2006-160 12/1 12/8 Olney Richland 33/unk 17/16 D,V Person-person Norovirus G1 C Hospital 0 Retirement IL2006-173 12/1 12/8 Elmhurst DuPage 66/unk 6/60 D,V Person-person Norovirus S facility 4

IL2006-195 12/1 12/25 Chicago Cook 26/75 9/17 D,V Person-person Norovirus G2 C LTC 2

IL2006-179 12/2 12/21 Morrison Whiteside 45/172 23/22 D,V Person-person Norovirus G2 C Hospital 4

IL2006-163 12/2 12/12 Chicago Cook 14/496 4/10 D,V Person-person Norovirus G2 C LTC

231 5

IL2006-156 12/2 12/10 Walnut Bureau 66/124 30/36 D,V Person-person Norovirus G2 C LTC 6

IL2006-178 12/3 1/11 Sterling Whiteside 76/925 76/0 D,V Person-person Norovirus G2 C Hospital 2 S. pyogenes/ IL2006-210 12/3 12/4 Chicago Cook 2/unk 0/2 Invasive Unknown Invasive C LTC 4

IL2006-162 12/3 12/6 Fairbury Livingston 24/61 4/20 D,V Person-person Norovirus G2 C LTC 8

IL2006-164 12/3 12/19 Elmhurst Dupage 21/unk 6/15 D,V Person-person Norovirus G2 C Hospital LTC 8

IL2006-180 12/3 12/19 Staunton Macoupin 43/173 16/27 D,V Person-person Norovirus G2 C LTC 0

IL2006-206 12/4 12/20 E. Dubuque Jo Daviess 100/525 3/97 D,V Person-person Norovirus S School 0

IL2006-168 12/4 12/9 Westmont Dupage 9/unk 0/9 D,V Person-person Norovirus S LTC 3

IL2006-183 12/6 12/11 Evanston Cook 3/unk 0/3 D Person-person C. difficile C LTC 2 Assisted and independent IL2006-190 12/7 12/30 Oak Park Cook 58/unk 8/50 D,V Person-person Norovirus C living 0

IL2006-185 12/8 12/15 Rockford Winnebago 39/unk 4/35 D,V Person-person Norovirus S LTC 0 Retirement IL2006-182 12/9 12/17 Vernon Hills Lake 26/240 1/25 D,V Person-person Norovirus S facility 7

IL2006-177 12/9 12/14 Chicago Cook 17/unk 2/15 D,V Person-person Norovirus G2 C Hospital 2

IL2006-184 12/11 12/19 Macon 38/87 5/33 D,V Person-person Norovirus G2 C LTC

232 0

IL2006-207 12/11 1/19/07 Elizabeth Jo Daviess 103/640 0/103 D,V Person-person Norovirus S School 2

IL2006-189 12/12 12/18 Chicago Cook 18/unk 18/0 D,V Person-person Norovirus G1&G2 C Hospital 0

IL2006-192 12/17 12/21 LeRoy McLean 37/222 7/30 D,V Person-person Norovirus S LTC 3

IL2006-196 12/18 12/27 Godfrey Madison 48/unk 17/31 D,V Person-person Norovirus G2 C LTC 0

IL2006-193 12/18 12/29 Rushville Schuyler 39/106 23/16 D,V Person-person Norovirus S LTC 8

IL2006-201 12/21 1/12 Evanston Cook 32/unk 15/17 D,V Person-person Norovirus G2 C LTC 0

IL2006-212 12/24 1/10 Litchfield Montgomery 53/167 12/41 D,V Person-person Norovirus S LTC 1

IL2006-194 12/26 12/29 McHenry McHenry 4/98 0/4 D,V Person-person Norovirus G1 S LTC 1

IL2006-203 12/28 1/18 Paxton Ford 66/149 23/43 D,V Person-person Norovirus G2 S LTC 5

IL2006-198 12/30 1/9 Chicago Cook 42/180 13/29 D,V Person-person Norovirus G2 C LTC 1

IL2006-199 12/30 1/15 Polo Ogle 30/95 15/15 D,V Person-person Norovirus S LTC 0

IL2006-208 12/30 Nokomis Montgomery 28/unk 28/ D,V Person-person Norovirus S LTC * D=diarrhea, F=fever, V=vomiting, SSTI=skin and soft tissue infection

233 Table 20. Reported Cases of Infectious Disease in Illinois, 2006 Disease Number Disease Number AIDS and HIV-report year 1,254 AIDS; Legionnaires disease 128 1,876 HIV Amebiasis cases, symptomatic 75 Leprosy 3 Anthrax 0 Leptospirosis 3

Arbovirus infection (WNV, (215 , 6,0,0) Listeriosis 31 Dengue, SLE, CE) Aseptic meningitis or encephalitis 935 Lyme disease 110 of unknown etiology Aseptic meningitis or encephalitis 137 Malaria 83 of known etiology-not arbovirus Blastomycosis 119 Measles 0 Botulism 2 Meningococcal, invasive 46 Brucellosis 8 1 Campylobacteriosis 1,294 Mumps 798 Chickenpox 1,915 Pertussis 588 Chlamydia trachomatis 53,586 Psittacosis 0 Cholera 1 Q fever 17 Cryptosporidiosis 258 Rabies, animal 46 Cyclospora 1 Rabies, potential human exposure 314 Cysticercosis 0 Reyes syndrome 0 Diphtheria 0 Rocky Mountain spotted fever 26 Ehrlichiosis, human granulocytic 6 Rubella 0 Ehrlichiosis, human monocytic 25 Salmonellosis 1,603 Ehrlichiosis, unknown type 1 Shigellosis 720 E. coli, shiga toxin producing 125 S. aureus, vancomycin resistant 0 Food and waterborne outbreaks 69 (5 recreational Streptococcus, group A, invasive 326 water) Giardiasis 695 Streptococcus, group B, invasive 89 Gonorrhea 20,186 Streptococcus pneumoniae, invasive 1,150 H. influenzae, invasive disease 120 Syphilis, primary or secondary 431 Hantavirus 0 Tetanus 1 Hemolytic uremic syndrome 8 Toxic shock syndrome 2 Hepatitis A, acute 109 Trichinosis 0 Hepatitis B, acute 132 Tuberculosis 569 Hepatitis C, acute 13 Tularemia 1 Hepatitis C, chronic or resolved 6,843 Typhoid fever 18 Histoplasmosis 112 Yersiniosis 31

234 Methods Health care professionals - including infection control nurses, physicians and school nurses - are required by Illinois law to report specific infectious diseases to their local health department. There are 97 local health departments in Illinois. Some serve a city or district, some serve the entire county and some serve residents of several counties. The local health department reports cases to the Illinois Department of Public Health, which, in turn, reports all nationally notifiable diseases to the United States Centers for Disease Control and Prevention (CDC). All information about patients is confidential; case reports to the CDC do not identify patients. This annual report includes only cases reported to the Department. Therefore, these annual numbers will underestimate the total number of cases of each disease in the state. Some patients with disease do not seek medical attention, some may not have the necessary testing done for a diagnosis, or the medical provider may not report the case to public health authorities. Also, to standardize reporting in the state, only cases that are reported and meet the case definition for that disease are included in case counts. For some diseases, a case definition is listed for both confirmed and probable cases. For all diseases except HIV/AIDS, the number of cases reported in a year is closed out in May of the following year. If cases from the preceding year are reported after the May date, they are not included in the preceding year’s numbers. For HIV/AIDS, there are two categories: number of cases reported in a given year versus number of cases diagnosed in a given year. The number of cases diagnosed in a given year is continually updated even if there is an extremely long delay in reporting a case. The number of cases reported for HIV/AIDS is what is used in this report. Reportable diseases diagnosed in college students living away from home and in residents of prisons, long-term care or other residential facilities are reported in the jurisdiction where the patient resides at the time of diagnosis. This results in attributing to rural counties that have a college or prison high incidence rates of certain diseases. Persons who are residents of Illinois but are not citizens of the United States may be counted. Persons who are visiting the United States and become clinically ill with malaria are counted in malaria statistics. Residents of other states who become ill in Illinois are not counted in this state’s statistics but are transferred to the state of residence. However, temporary workers in Illinois are counted in Illinois statistics. The Illinois population used to calculate incidence rates and race and ethnicity proportions in past editions of this document was from the 2000 census data.. The following table shows the age distribution of the Illinois population as determined by the 2000 census.

235

Age category Census % of population numbers used for 2000 annual report

<1 year 173,373 1

1-4 years 703,176 6

5-9 years 929,858 7

10-19 years 1,799,099 14

20-29 years 1,742,602 14

30-59 years 5,108,274 41

>59 years 1,962,911 15

TOTAL 12,419,293

Where it was deemed useful, graphs were produced showing the number of cases by month, the number of cases by year since 2001 and the age distribution. Incidence rates were calculated by age for diseases with higher numbers of cases. Incidence rate was calculated by taking the number of cases in a category, dividing by population size from 2000 census data and multiplying by 100,000. If an annual incidence rate was calculated for the period 2002 to 2006, it was reached by taking the number of cases reported from 2002 through 2006, dividing by the population and multiplying by 100,000; it was then annualized by dividing by five. The reports for each disease were generated from the INEDSS database. The criteria used were year reported = 2006. For diseases where asymptomatic cases do not meet the case definition (hepatitis A and amebiasis) these laboratory confirmed cases were not included in the detailed information in the disease information. The epidemiologic information presented for each disease is for 2006 only, unless otherwise specified. For some diseases, where the number of cases by year was low, information may have been combined for multiple years to allow demonstration of trends by month and age. When the case population differed from the Illinois population in the racial distribution, a chi- square test for a significant difference in proportions was done using the Epi-Info software package. Suggested reading lists are provided for some diseases.

236