Legionellosis

OR 1. Case Definition

1.1 Confirmed Case: Clinical illness1 with  Specific antigen or staining laboratory confirmation of infection: of the organism in respiratory  Isolation of Legionella species from secretions, lung tissue, or pleural fluid respiratory secretions, lung tissue, by direct fluorescent antibody (DFA) pleural fluid or other specimens staining, immunohistochemistry collected from normally-sterile body (IHC), or other similar method (1, 2). sites; 2. Reporting and Other OR Requirements  A significant (e.g., fourfold or greater) rise in Laboratory serogroup 1-specific IgG titre between  All positive laboratory results are acute and convalescent sera; reportable by laboratory to the Public Health Surveillance Unit (204-948-3044 OR secure fax).  Demonstration of L. pneumophila  Clinical laboratories are required to serogroup 1 antigen in urine submit residual specimens from specimens (1). individuals who tested positive for Legionella species to Cadham 1.2 Probable Case: Clinical illness1 and Provincial Laboratory (CPL) within demonstration of: seven days of report.  Fourfold or greater rise in antibody Health Care Professional: titer to specific species or serogroups  Probable cases are reportable to the of Legionella other than L. pneumophila Public Health Surveillance Unit by serogroup 1 (e.g. L. micdadei, L. secure fax (204-948-3044) ONLY if a pneumophila serogroup 6); positive lab result is not anticipated

(e.g., poor or no specimen taken, OR person has recovered) (form available

at:  Fourfold or greater rise in antibody www.gov.mb.ca/health/publichealth titer to multiple species of Legionella /cdc/protocol/form2.pdf ). using pooled antigen;  Cooperation in Public Health

investigations is appreciated.

Regional Public Health: 1 Legionellosis comprises two distinct illnesses:  For laboratory-confirmed cases, the Legionnaires’ disease, characterized by fever, myalgia, Communicable Disease Control cough and , and Pontiac fever, a milder illness without pneumonia (1). Investigation Form

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(www.gov.mb.ca/health/publichealth Pontiac fever is caused by inhalation of a /cdc/protocol/form2.pdf) should be disease-causing environmental aerosol completed by regional Public Health derived from water containing and returned to the Public Health microorganisms, including Legionella bacteria Surveillance Unit by secure fax (204- (7). The initial symptoms are the same as 948-3044). those for Legionnaires’ disease, but Pontiac fever is a milder, self-limited -like 3. Clinical Presentation/Natural illness without pneumonia (3 - 5). Fever, History myalgia, headache and weakness are the major symptoms (7). Cough, dyspnea, Legionellosis is an acute bacterial disease anorexia, arthralgia and abdominal pain are with two distinct clinical and epidemiological less common (7). Patients recover in two to manifestations, Legionnaires’ disease and five days without treatment (3). Pontiac fever (3 - 5). Legionnaires’ Disease: 4. Etiology Legionnaires’ disease is characterized by Gram-negative bacterium of the genus anorexia, malaise, myalgia, headache and Legionella (8). They are ubiquitous in fresh fever (3). Patients may develop a non- water and occur naturally as intracellular productive cough (3, 5). Symptoms may parasites of amoebae (9). Legionella persist for several months (6). Legionnaires’ pneumophila serogroup 1 is most commonly disease is a common cause of pneumonia that associated with disease (3). At least 20 may be mild or severe (3, 4). Abdominal pain different species have been implicated in and diarrhea are also common (3). If human disease (4), including L. longbeachae untreated, Legionnaires’ disease usually and L. micdadei (10). L. longbeachae is usually worsens clinically during the first week associated with exposures to potting soil (7, following onset of symptoms (5). Renal 10, 11). manifestations (4) and central nervous system disorders including confusion, delirium, 5. Epidemiology depression, disorientation and hallucination 5.1 Reservoir and Source may occur (5). The illness can progress to and death (4, 5). The The bacteria are found worldwide in many radiographic pattern of Legionnaires’ disease different natural and artificial aquatic is indistinguishable from that seen in other environments such as cooling towers, water causes of pneumonia (5). The average fatality systems in hotels, homes, ships and factories; rates for sporadic disease are estimated to be respiratory therapy equipment; fountains; about 10% to 15% (7). misting devices; and spa pools (5). In natural water sources such as lakes, rivers, ponds and Pontiac Fever: streams, Legionella bacteria are generally at Neither the pathogenesis nor the cause of levels that are too low to cause infection in Pontiac fever is known with certainty (7).

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humans (6). Legionella may remain dormant (3). Outbreaks of legionellosis have been in cool water and multiply when water attributed to exposure to contaminated temperatures increase (11, 12). Water cooling towers, evaporative condensers, temperature is an important determinant in potable water systems, whirlpool spas, hot the colonization of water distribution systems tubs, humidifiers and respiratory therapy (5). Warm water (25 - 40°C), which supports equipment (4, 14-16). Outbreaks have the highest concentration of these bacteria, is occurred in hospitals, hotels, and other large the major bacterial reservoir leading to buildings as well as on cruise ships (4). Legionnaires’ disease (7). L. pneumophila has Legionnaires’ disease can be acquired at a been shown to be able to withstand distance from contaminated sources such as temperatures of 50°C for several hours but cooling towers or air scrubbers, when the does not multiply below 20°C (5). Other exhaust is carried by prevailing winds (17 - factors that can promote the proliferation of 19). Legionella in water distribution systems 5.3 Occurrence: include water quality, system design, the material used in construction and the 5.3.1 General: presence of biofilms (5). Environmental The incidence of legionellosis worldwide is changes that disrupt the biofilm can result in unknown, and countries differ greatly in the sudden and massive release of Legionella methods for detection and reporting of cases bacteria into the surrounding water (7). (5). Attack rates of legionellosis in outbreaks Contaminated water that is aerosolized are low, about 0.1% to 5%; however, Pontiac allows dissemination of the bacteria into the fever has attack rates as high as 95% (3). environment (7). Most cases of legionellosis are sporadic (20, 5.2 Transmission 21). There is evidence that the risk for Legionnaires’ disease might be higher under Legionnaires’ disease is acquired through certain environmental conditions; warm and inhalation of aerosolized water contaminated wet weather has been associated with higher with Legionella (4). Rarely, transmission may incidence rates in the Netherlands and the occur through aspiration of contaminated United Kingdom (22) and part of the United water (7, 12). In some cases of legionellosis, States of America (20). A significant number no aquatic source was implicated; sources of of legionellosis cases are travel-associated (22, infection were thought to be potting soils and 23). The incidence of Legionnaires’ disease in soil conditioners (5). The precise mode of the United States and elsewhere appears to be transmission from soil is uncertain (13). increasing, based on the number of cases There is no established dose-response reported to public health agencies; however, relationship for Legionella infections, and the it is unclear whether the increase is due to concentration of legionellae necessary to diagnostic testing patterns, better reporting cause an outbreak is unknown (5). and surveillance or a true disease increase Nosocomial cases usually make up a small (24). proportion of reported cases of legionellosis

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5.3.2 Canada: 5.6 Period of Communicability: The average number of reported cases of Person-to-person transmission has not been Legionnaires’ disease is generally less than documented (4, 8). 100 per year (6). However, the actual number 6. Diagnosis of cases is likely much higher, as many people with pneumonia may not be tested for A diagnosis of legionellosis should be infection with Legionella (6). Large outbreaks considered in any cluster of respiratory attributed to cooling towers occurred in illness with pneumonia. Toronto (2005) and Quebec City (2012) with Obtaining a specimen for culture of the case fatalities. In Canada, sporadic cases and organism is preferred as it can help to outbreaks are more common in summer and identify the source of the infection if autumn (6). suspected environmental sources can be 5.3.3 Manitoba: sampled. Appropriate samples for culture Thirty-two cases of legionellosis were include sputum, bronchoalveolar lavage fluid, reported to Manitoba Health, Healthy Living pleural fluid or pulmonary tissue. Urine and Seniors from 2000-2013. Reported cases antigen tests are highly specific and are used occurred in individuals who were 20 years of during the acute phase of the illness (23); age or older. On average, three or fewer however, they only detect infection with L. cases were reported per year. pneumophila serogroup 1 (10). Seroconversion or a fourfold or greater rise in Legionella 5.4 Incubation Period: species antibody between acute and The incubation period for Legionnaires’ convalescent sera is also diagnostic. Up to disease is usually five to six days, but ranges twelve weeks may be required for antibody from two to 10 days (3). The incubation levels to peak. Considering the extended period for Pontiac fever is most often 24 - 48 period needed for significant rise in antibody hours but ranges from five to 72 hours (3). titres, serology is a less useful option for the diagnosis of acute cases, but is helpful for 5.5 Host Susceptibility and Resistance: retrospective analyses and sero- Risk factors for Legionnaires’ disease include epidemiological investigations. increasing age, smoking, male sex, chronic lung disease, hematologic malignancies, end- 7. Key Investigations for Public stage renal disease, lung cancer, Health Response immunosuppression including steroid Individual cases of legionellosis should be therapy, and diabetes (9, 23). Circulating promptly investigated as they may be the antibodies are produced during L. first indication of a common exposure pneumophila infections in humans, but do not outbreak. seem to be protective (5). There appear to be  Review possible sources of infection: no predisposing host factors for Pontiac fever o Travel history; (7).

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o Exposures to aerosolized water Consultation with an infectious diseases e.g., hot tubs, spas, nebulizers, specialist is recommended for the humidifiers; management of Legionnaires’ disease (8). o Recent hospitalization. Treatment:  Conduct environmental sampling of suspected source if appropriate. 1) Outpatient with mild pneumonia who is  Public health inspectors are not immunocompromised: Erythromycin, responsible for the investigation of doxycycline, azithromycin, levofloxacin, contaminated recreational water. The ciprofloxacin, moxifloxacin or clarithromycin PHI (Public Health Inspector) are first choice (7). recreational water specialist can be 2) Hospitalized patient with pneumonia or contacted through your local Public immunocompromised patient: Azithromycin Health Office or levofloxacin is preferred (7). http://www.gov.mb.ca/health/publi Infection Control Measures: chealth/environmentalhealth/protecti  For cases in health care facilities, refer on/contact.html . to page 91 of the Manitoba Health 8. Control document Routine Practices and Additional Precautions: Preventing the Appropriate building maintenance to reduce Transmission of Infection in Health Care biological hazards that may affect employees available at: or the public. Refer to the Workplace Safety http://www.gov.mb.ca/health/publi and Health Act – Section 18(1) d - chealth/cdc/docs/ipc/rpap.pdf . http://web2.gov.mb.ca/laws/statutes/ccsm /w210e.php . Refer also to the Workplace 8.2 Management of Contacts: Safety and Health Regulations: Contacts are at risk only if exposed to the http://web2.gov.mb.ca/laws/regs/current/ same source as a case of legionellosis. The 217.06.pdf : attack rate for Legionnaires’ disease is quite  Part 4.6 – Drinking Water (Employer low, but is high for Pontiac Fever. must supply safe potable water for employees.) 8.3 Management of Outbreaks:  Part 36 – Chemical and Biological An outbreak is defined as the occurrence of substances (All chemical and case(s) in a particular area and period of time biological hazards need to be in excess of the expected number of cases. addressed in the workplace.) Detection of travel-related outbreaks of legionellosis is difficult due to low attack 8.1 Management of Cases: rates, long incubation periods, dispersal of Pontiac fever requires supportive care only as persons away from the source of infection, the illness is self-limited and antibiotics have and inadequate surveillance (9). no benefit (8).

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 Outbreaks should be investigated to biofilms according to the identify a common source of infection manufacturers’ directions (19). and prevent further exposure to that source. The extent of outbreak 8.5 Important Prevention Resources investigations will depend upon the  Manitoba Workplace Safety and number of cases, the likely source of Health contamination and other factors. http://www.gov.mb.ca/labour/safet  Public notification should occur. The y/ level of notification will usually be at  Control of Legionella in Mechanical the discretion of regional Public Systems http://www.tpsgc- Health and/or the provincial Public pwgsc.gc.ca/biens- Health Division for local outbreaks property/documents/legionella- but may be at the discretion of the eng.pdf Federal Government for nationally  Legionella and the prevention of linked outbreaks. legionellosis  Decontamination of implicated water http://www.who.int/water_sanitatio sources based on regional n_health/emerging/legionella.pdf requirements and jurisdiction. References 8.4 Preventive Measures: 1. Public Health Agency of Canada. Case  Cooling towers should undergo Definitions for Communicable Diseases under regular maintenance and should be National Surveillance. Canada Communicable drained when not in use. Appropriate Disease Report CCDR 2009; 35S2: 1-123. biocides should be used to limit the 2. Centers for Disease Control and Prevention. growth of slime-forming organisms. CSTE Position Statement: Strengthening  Proper maintenance of mist-producing Surveillance for Travel-Associated devices, such as shower heads, hot Legionellosis and Case Definitions for tubs, whirlpool bathtubs and Legionellosis. Available at: humidifiers according to the http://www.cdc.gov/legionella/health- manufacturers’ directions (6, 10, 14). depts/CSTE-position-statement.html .  Avoidance of high risk areas, such as 3. Heymann David L. Legionellosis. In: whirlpool spas by individuals at Control of Communicable Diseases Manual 19th ed, increased risk of infection such as the American Public Health Association, elderly and those with Washington, 2008; 337-340. immunocompromising conditions 4. American Academy of Pediatrics. Legionella (e.g., cancer, diabetes) (8). pneumophila Infections. In: Pickering LK ed.  Sterile water should be used for Redbook 2012 Report of the Committee on Infectious respiratory therapy devices. Diseases 29th ed. Elk Grove Village, IL:  Appropriate maintenance of water American Academy of Pediatrics, 2012; 461-462. systems to prevent the formation of

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5. World Health Organization. Legionella and 13. Muder RR and Yu VL. Infection Due to the prevention of legionellosis, 2007. Available Legionella Species Other Than L. pneumophila. at: Clinical Infectious Diseases 2002; 35: 990 – 998. http://www.who.int/water_sanitation_health 14. Den Boer JW, Yzerman EPF, Schellekens J et /emerging/legionella.pdf . al. A Large Outbreak of Legionnaires’ Disease 6. Public Health Agency of Canada. Legionella. at a Flower Show, the Netherlands, 1999. Available at: http://www.phac-aspc.gc.ca/id- Emerging Infectious Diseases 2002; 8(1): 37-43. mi/legionella-eng.php . 15. Burnsed LJ, Hicks LA, Smithee LMK et al. 7. Hill DR and Nash TE. Legionnaires’ Disease A Large, Travel-Associated Outbreak of In: Mandell GL, Bennett JE, Dolin R eds. Legionellosis among Hotel Guests: Utility of Principles and Practice of Infectious Diseases 7th ed. the Urine Antigen Assay in Confirming Pontiac Elsevier, Philadelphia, 2010. Fever. Clinical Infectious Diseases 2007; 44: 222- 228. 8. Centers for Disease Control and Prevention. Legionellosis (Legionnaires’ Disease & Pontiac 16. Garcia-Fulgueiras A, Navarro C, Fenoll D et Fever). CDC Yellowbook 2014. Available at: al. Legionnaires’ Disease Outbreak in Murcia, http://wwwnc.cdc.gov/travel/yellowbook/20 Spain. Emerging Infectious Diseases 2003; 9(8): 14/chapter-3-infectious-diseases-related-to- 915-921. travel/legionellosis-legionnaires-disease-and- 17. Marrie TJ, Garay JR and Weir E. pontiac-fever . Legionellosis: Why should I test and report? 9. Fields BS, Benson RF and Besser RE. Canadian Medical Association Journal 2010; Legionella and Legionnaires’ Disease: 25 Years 182(14): 1538 – 1542. of Investigation. Clinical Microbiology Reviews 18. Nygård K, Werner-Johansen ø, Rømsen S et 2002; 15(3): 506-526. al. An Outbreak of Legionnaires Disease 10. Murray S. Legionella infection. Canadian Caused by Long-Distance Spread from an Medical Association Journal 2005; 173(11): 1322. Industrial Air Scrubber in Sarpsborg, Norway. Clinical Infectious Diseases 2008; 46: 61- 69. 11. Potts A, Donaghy M, Marley M et al. Cluster of Legionnaires’ disease cases caused by 19. Health Protection Scotland. Guideline on serogroup 1, Scotland, the management of Legionella cases, incidents, August to September 2013. Euro Surveill 2013; outbreaks and clusters in the Community 18(50). Available online: November 2014. Available at: http://www.eurosurveillance.org/ViewArticle http://www.documents.hps.scot.nhs.uk/about .aspx?ArticleId=20656 . -hps/hpn/legionella-guidelines-2014-2.pdf 12. European Centre for Disease Prevention 20. Hicks LA, Rose CE, Fields BS et al. and Control. European Legionnaires’ Disease Increased rainfall is associated with increased Surveillance Network (ELDSNet) Operating risk for legionellosis. Epidemiol Infect 2007; 135: procedures 2012. Available at: 811 – 817. http://www.ecdc.europa.eu/en/healthtopics/ 21. European Centre for Disease Prevention legionnaires_disease/pages/index.aspx . and Control. ECDC Surveillance Report

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Legionnaires’ Disease in Europe 2012. Available at: http://www.ecdc.europa.eu/en/publications/ publications/legionnaires-disease-surveillance- 2012.pdf . 22. Beauté J, Zucs P and de Jong B. Risk for Travel-associated Legionnaires’ Disease, Europe, 2009. Emerging Infectious Diseases 2012; 18(11): 1811-1816. 23. Centers for Disease Control and Prevention. Legionellosis---United States, 2000—2009. Morbidity and Mortality Weekly Report (MMWR) 2011; 60(32): 1083 – 1086. 24. Neil K and Berkelman R. Increasing Incidence of Legionellosis in the United States, 1990-2005: Changing Epidemiologic Trends. Clinical Infectious Diseases 2008; 47: 591- 599.

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