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Home , Arbovirus, West Nile fever

Volume 23, No. 4 July 2003

Surveillance for In this issue... West Nile Update 13 To monitor for human West Nile (WNV) Arbovirus Surveillance 13 and other arbovirus infections in Laboratory Testing 14 , the Department of Public Health’s Reporting Form 15 (DPH), Laboratory Division tests and specimens from persons Of the 10 hospitalized cases, the median age was hospitalized with specified neurologic . 62 years. Illness was most frequently In 2002, the DPH tested 138 serum and characterized by , difficulty walking, cerebrospinal fluid specimens from 93 persons with confusion, and . Onset of illness suspect WNV infection, 41 (44%) were reported preceded hospital admission by 0-7 days with or , 50 (54%) (median: 2.5 days). The length of hospital stay with aseptic (age > 17 years), and 2 ranged from 2-11 days (median: 6 days). The (2%) with Guillian-Barre . At physician’s outpatients were younger (median: 44 years) and requests, an additional 308 persons with a variety most frequently had fever, , , and of other clinical syndromes were also tested. muscle aches. None of the patients died. Of the persons tested for WNV infection, 17 (18%) Onset of symptoms occurred between July 29, were confirmed. Of these, 10 (59%) were and September 30, 2003 with the majority (71%) hospitalized with neurologic and 7 (41%) occurring during August 19-September 2, 2003 were outpatients initially tested at a commercial (Figure 2). Human cases coincided with statewide laboratory. Of the confirmed cases, diagnosis of 8 increases in dead bird sightings, and confirmation was based on elevated IgM levels specific to WNV of WNV infection in birds and mosquitoes. in serum, 2 in CSF, and 7 on elevated IgM in both Among the 14 persons with confirmed WNV serum and CSF. The median age of cases was 45 infection who were interviewed, 11 (79%) reported years (range: 24-81 years). Cases included outdoor activities without taking precautions residents of 4 towns in Fairfield County, 3 towns in against bites when mosquitoes were Hartford County, and 3 towns in New Haven present in the 2 weeks prior to symptom onset. County (Figure 1). Reported by: R Nelson, DVM, MPH, L Wilcox, MPH, Figure 1 and Emerging Infections Program; T Brennan, Surveillance Results Connecticut, 2002 Figure 2 West Nile Virus Cases by Week of Onset Connecticut, 2002 8

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2 Number of Cases, n=17 Cases, of Number 1

0 July Aug Aug Aug Aug Sept Sept Sept Sept Sept 29 5 12 19 26 2 9 16 23 30 Week of Onset 13 Connecticut Epidemiologist

BA, ScD, State Public Health Laboratory, Connecticut window and door screens at home. Older Department of Public Health. persons should take warnings of WNV seriously. Editorial Note: Since exposure to mosquitoes varies by season In 2002, WNV was reported from 44 states and the and geographic region, clinicians should take a District of Columbia (DC). As of November 30, thorough travel history from patients with 2002 3389 human cases of WNV-associated illness neurologic illness and be alert to the possibility of were reported nationally. Of these, 2354 (69%) had arboviral infection, especially in persons with West Nile meningoencephalitis (WNME), 704 (21%) heavy mosquito exposure around the home. In had (WNF), and 331 (10%) had an Connecticut, the risk of humans acquiring WNV unspecified illness. A total of 201 occurred infection is highest during August – September. including 199 (8.5%) of patients with WNME and 2 In Connecticut, encephalitis became physician (0.3%) with WNF. Human cases were reported from reportable in January 2000. To report a case of 37 states and DC (1). encephalitis, please notify the local health In 2002, person-to-person of WNV via department in the patient’s town of residence and ingestion of breast milk, transplacental infection, the DPH Epidemiology Program (860-509-7994 transfusion of blood products, and organ or 860- 509-8000 after hours) by mail or phone transplantation (2-4) were reported to the CDC. In within 12 hours of diagnosis. May 2003, the Food and Drug Administration issued References: guidelines for screening potential blood donors. On July 1, 2003 the Red Cross began testing blood and 1. CDC. Provisional Surveillance Summary of the West Nile Virus – , January-November reporting positive findings to donors advising them 2002. MMWR 2002;51:1129-1132. to seek medical attention. Results will also be 2. CDC. Possible West Nile Virus Transmission to an reported to the DPH. The DPH will interview all Infant Through Breast-Feeding-Michigan, 2002. MMWR WNV positive patients about mosquito exposure 2002, 51:877. and the possibility of other modes of transmission. 3. CDC Intrauterine West Nile Virus Infection-New York, 2002. MMWR 2002, 15:1135. 4. CDC. Update: Investigations of West Nile Virus In Connecticut, WNV in mosquitoes, birds, horses, Infections in Recipients of and or people was identified in 102 towns and in all -Michigan, 2002. MMWR 2002, eight counties (Figure 1). Of dead birds tested, 528 51:877. (57%) tested positive for WNV. Of these, 501 (95%) 5. Connecticut Department of Agriculture. West Nile Virus were crows and 27 (5%) were other bird . in Domestic Animals & Birds. Available at: http://www. state.ct.us/doag/wnvfact2.htm. Accessed July 1, 2003. Positive birds were found between May 20 through October 23, 2003. WNV was also identified in 4 Laboratory Testing for WNV horses (5) and, according to the Connecticut Agricultural Experiment Station (Theodore Free arbovirus testing will be performed at the Andreadis, PhD, personal communication June State Laboratory on and paired specimens 2003), 73 pools of mosquitoes. from persons hospitalized for suspected: encephalitis, meningoencephalitis, Guillain-Barre In 9 of the 10 towns with a human case of WNV, an syndrome with fever, or in infected crow was found before onset of illness persons aged > 17 years. For free testing, an (median: 38 days). Positive mosquitoes were Encephalitis/Meningoencephalitis Initial Report identified in 5 of the 8 towns with mosquito trapping Form (see page 15) must accompany sites. Form, OL42A. The case report form requests the In 2003, surveillance will again be conducted for minimum information needed for the purposes of WNV in wild birds, domestic animals, mosquitoes, surveillance. and people. The surveillance goals are to determine Convalescent serum specimens should be if WNV is present and/or amplifying, and to guide submitted for all patients with negative WNV prevention activities. Individuals should use test results from specimens collected prevention measures when outdoors in areas with during the first week of illness. In some confirmed potential exposure to mosquitoes. Individuals WNV infection cases, acute specimens tested should also reduce standing water and fix holes in negative IgM . (Continued on page 16) 14 Connecticut Epidemiologist

State of Connecticut Department of Public Health Epidemiology Program Encephalitis / Meningoencephalitis 410 Capitol Avenue, MS#11EPI Initial Reporting Form P.O. Box 340308 Hartford, CT 06134-0308 A completed form must accompany requests for West Nile virus testing in addition to the laboratory request form, OL42A. If you have questions concerning the information requested please contact the Epidemiology

Program at (860) 509-7994. Rev. 5/2003

Patient Information

Last Name First Name Date of Birth / / Age Address City County State Zip Code Telephone Home ( ) Work ( ) Sex † Male † Female Race † White † Black † Am Indian/Alaskan † Asian † Other † Unknown Hispanic † Yes † No † Unknown

Clinical Information

Hospitalized † Yes † No Hospital Name City State Date of Admission / / Date of Symptom Onset / / Date of First Neurologic Symptom / / Current Diagnosis † Encephalitis † Meningoencephalitis † Menigitis † Other Did patient die of this illness? † Yes † No † Unknown

Travel History City State Country Travel during the 14 days before onset of illness:

Specimens Being Submitted for Testing

† CSF Date collected / / † Serum Date collected / / † Other (specify) Date collected / /

NOTE: Convalescent serum specimens should be submitted for all patients with negative specimens collected during the first week of illness.

Requesting Physician

Date of Report / / mm dd yyyy

Last Name First Name Work Address State Zip Code Telephone Numbers Work ( ) Pager ( ) Work ( )

15 Connecticut Department PRSRT STD of Public Health U.S. Postage 410 Capitol Ave., MS11EPI PAID P.O. Box 340308 Hartford, CT Hartford, CT 06134-0308 Permit No. 4313

16 In This Issue... West Nile Virus Update: Arbovirus Surveillance, Laboratory Testing, Reporting Form

(Continued from page 14) Mild illness The Encephalitis/Meningoencephalitis Initial Report Form must be completed and Testing for WNV is not provided at the State accompany each specimen or set of specimens Laboratory for persons suspected of having submitted for testing. Testing may be delayed WNV infection on the basis of mild illness or on specimens that are not accompanied by the recent mosquito bites. Specimens from two necessary forms. outpatients can be submitted to commercial or hospital laboratories. Acute serum and CSF specimens will be tested for IgM antibodies to several Specimen types and amounts: including: WNV, eastern equine encephalitis • Acute specimens should be collected within (EEE), western equine encephalitis (WEE), 14 days of onset of symptoms. California encephalitis group (CEG), St. Louis Convalescent specimens should be collected encephalitis (SLE) and . 2-3 weeks later. Negative results will be reported 2-4 days after • Please send > 5.0 ml of serum and > 1.0 ml receiving the specimen and completed case of CSF. Do not send whole blood. report form. Positive results may take longer if • Frozen brain tissue and acute CSF confirmatory testing is done by the CDC. specimens can also be submitted for virus Paired serum specimens will be tested for IgM isolation. Virus isolation will not be attempted and IgG antibodies to WNV, EEE, WEE, CEG, unless specifically requested. and SLE. In addition, tests for IgG antibodies to For free testing, please write “WNV TESTING” or herpes, varicella, cytomegalovirus, and “ENCEPHALITIS” on the Virology Form OL42A. Jamestown Canyon virus will be included. Convalescent specimens should be clearly If you have additional questions concerning labeled for appropriate testing. Forms can be WNV surveillance, please contact the obtained by calling (860) 509-8501. Epidemiology Program at (860) 509-7994.

John G. Rowland, Governor AIDS Epidemiology (860) 509-7900 Connecticut Epidemiologist Joxel Garcia, MD, MBA., Commissioner of Health Epidemiology (860) 509-7994 Immunizations (860) 509-7929 Editor: Matthew L. Cartter, MD, MPH James L. Hadler, MD, MPH Pulmonary (860) 509-7722 State Epidemiologist Sexually Transmitted Assistant Editor: Starr-Hope Ertel Division of Infectious Diseases Diseases (STD) (860) 509-7920