Georgia Department of Human Resources (DHR) Division of Public Health LEGIONELLOSIS FACT SHEET (Legionnaires' disease, Pontiac fever) (updated April 2008) Agents: Legionella pneumophila and other Legionella species. Brief Description: Legionellosis has two clinically and epidemiologically distinct manifestations: Legionnaires' disease and Pontiac fever. Both illnesses are characterized by anorexia, malaise, myalgia, headache, and fever; however, Legionnaires' disease is associated with pneumonia, while Pontiac fever is a milder, non-pneumonic illness. Reservoir: Primarily aqueous. Drinking water from approximately 30% of municipal water systems in the United States will grow Legionella when cultured. Legionella-containing water that has been aerosolized by showers, air-conditioning cooling towers, evaporative condensers, humidifiers, respiratory therapy devices, whirlpool spas and decorative fountains have been implicated epidemiologically during outbreaks. There is evidence to suggest that locations in which the municipal water system is disinfected with monochloramine are less likely to have outbreaks of legionellosis. The organism has also been isolated from environmental sources such as water in creeks and ponds and soil along their banks. Potting soil has also been implicated as a source of Legionella in human cases of Legionnaires' disease. Mode of Transmission: Transmission is by inhalation of contaminated aerosols; person-to-person transmission does not occur. Outbreaks occur when two or more people develop symptoms after exposure to the same source. Risk Groups: Illness occurs most frequently among the elderly, cigarette smokers, persons with chronic lung or immunocompromising disease, and persons receiving immunosuppressive drugs. Incubation Period: For Legionnaires' disease: 2 to 10 days, most often 5 to 6 days. For Pontiac fever: 566 hours, most often 24-48 hours. Diagnostic Testing: Culture Referral 1. Specimen: Pure Culture 2. Outfits: (culture referral) 3. Lab Form: 3410 4. Lab Test Performed: Culture identification, confirmation, and/or serotyping 5. Lab: Bacteriology, Georgia Public Health Laboratory (GPHL) and CDC NOTE: All isolates from human cases may be forwarded to GPHL for confirmation & identification. GPHL will forward to CDC for serotyping. Treatment: Erythromycin is the drug of choice. Clarithromycin and azithromycin may be effective. Rifampin may be a valuable adjunct but should not be used alone. Investigation: Patient interview should focus on potential sources of infection, particularly related to common areas. A thorough travel history is required. Determine if other cases have occurred, indicating the possibility of a common source outbreak. Epidemiology Section 2 Peachtree Street NW 14th Floor Atlanta, Georgia 30303-3142 http://health.state.ga.us/ Georgia Department of Human Resources (DHR) Division of Public Health Case Classification: Legionellosis Clinical Criteria: a.) Legionnaires' disease: fever, myalgia, cough, and clinical or radiographic pneumonia, or b.) Pontiac fever: a milder illness without pneumonia. Confirmed Suspect A confirmed case meets the clinical A suspect case meets the clinical criteria and the following criteria and the following laboratory laboratory criteria: criteria: Fourfold or greater rise in antibody titer to specific Detection of Legionella pneumophila species or serogroups of Legionella other than L. serogroup 1 antigen in urine using pneumophila serogroup 1 (e.g., L. micdadei, L. validated reagents, or pneumophila serogroup 6), or Isolation of any Legionella organism Fourfold or greater rise in antibody titer to multiple from respiratory secretions, lung species of Legionella using pooled antigen and validated tissue, pleural fluid, or other normally sterile fluid, or Fourfold or greater rise in specific reagent, or Detection of specific Legionella antigen or staining of the organism in respiratory secretions, lung tissue, or pleural serum antibody titer to Legionella fluid by direct fluorescent antibody (DFA) staining, pneumophila serogroup 1 using immunohistochemstry (IHC), or other similar method, validated reagents. using validated reagents, or Detection of Legionella species by a validated nucleic acid assay. Reporting: Report cases WITHIN 7 DAYS to the local health department, District Health Office, or the Epidemiology Section electronically through the State Electronic Notifiable Disease Surveillance System (SENDSS) at http://sendss.state.ga.us, or complete and mail CDC Form 52.56 (revised Aug. 1999), Legionellosis Case Report http://www.health.state.ga.us/pdfs/epi/notifiable/legionella.crf.02.pdf for each reported case. Reported Cases of Legionellosis in Georgia, 1993-2007 Year Number of Cases 1993 35 1994 118 1995 19 1996 3 1997 6 1998 8 1999 5 2000 10 2001 12 2002 19 2003 35 2004 43 2005 39 2006 38 2007 43 Epidemiology Section 2 Peachtree Street NW 14th Floor Atlanta, Georgia 30303-3142 http://health.state.ga.us/ Georgia Department of Human Resources (DHR) Division of Public Health References: 1. Aspen Reference Group. Legionellosis (Legionnaires' Disease) In: Infectious Disease Resource Manual. Nell Di Lima S, and Eutsey D, Eds. Aspen Publishers, Inc. 1999: p. 3:73. th 2. Beneneson, A, ed. In: Control of Communicable Diseases Manual. 16 ed. Washington, DC: American Public Health Association, 1995: pp. 256-258. 3. Centers for Disease Control and Prevention. Legionellosis 2005 Case Definition. http://www.cdc.gov/ncphi/disss/nndss/casedef/legionellosis_current.htm. 4. Centers for Disease Control and Prevention. Sustained Transmission of Nosocomial Legionnaires Disease -- Arizona and Ohio. MMWR 1997; 46(19): 416-421. th 5. Chin J, ed. Legionellosis. In: Control of Communicable Diseases Manual. 17 ed. Washington, DC: American Public Health Association, 2000: pp. 281-283. Links: CDC Legionellosis Fact Sheet-www.cdc.gov/ncidod/dbmd/diseaseinfo/legionellosis_g.htm. Epidemiology Section 2 Peachtree Street NW 14th Floor Atlanta, Georgia 30303-3142 http://health.state.ga.us/