Lauren T Orkis1, Lee H Harrison2, Kristen J Mertz3, Maria M Brooks4, Kyle J Bibby5, Janet E Stout6. 1. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA, 15261, USA; Bureau of Assessment, Statistics, and Epidemiology, Allegheny County Health Department, 542 Fourth Ave. Pittsburgh, PA, 15219, USA. Electronic address: Lmt61@pitt.edu. 2. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA, 15261, USA; Infectious Diseases Epidemiology Research Unit, University of Pittsburgh Division of Infectious Diseases and Department of Epidemiology, 3550 Terrace Street, Pittsburgh, PA, 15261, USA. 3. Bureau of Assessment, Statistics, and Epidemiology, Allegheny County Health Department, 542 Fourth Ave. Pittsburgh, PA, 15219, USA. 4. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 130 DeSoto Street, Pittsburgh, PA, 15261, USA. 5. Department of Civil, and Environmental Engineering, University of Pittsburgh Swanson School of Engineering, 3700 O'Hara Street, Pittsburgh, PA, 15261, USA. 6. Department of Civil, and Environmental Engineering, University of Pittsburgh Swanson School of Engineering, 3700 O'Hara Street, Pittsburgh, PA, 15261, USA; Special Pathogens Laboratory, 1401 Forbes Ave #401, Pittsburgh, PA, 15219, USA.
Abstract
BACKGROUND: Most Legionnaires' disease in the US and abroad is community-acquired and believed to be sporadic, or non-outbreak associated. Most patients are exposed to numerous water sources, thus making it difficult to focus environmental investigations. Identifying known sources of sporadic community-acquired Legionnaires' disease will inform future sporadic Legionnaires' disease investigations as well as highlight directions for research. The objective is to summarize and rank sporadic Legionnaires' disease sources based on the level of linkage between the environmental source and cases. METHODS: A PubMed search was conducted using the search terms legion* and (origins or source or transmission) and (sporadic or community-acquired). Studies of nosocomial and/or outbreak-associated disease were excluded from this review. Definite, probable, possible and suspect ranks were assigned to sources based on evidence of linkage to sporadic Legionnaires' disease. RESULTS: The search yielded 196 articles and 47 articles were included in the final review after application of exclusion criteria. A total of 28 sources were identified. Of these, eight were assigned definite rank including residential potable water and car air-conditioner water leakage. Probable rank was assigned to five sources including solar-heated potable water and soil. Possible rank was assigned to nine sources including residential potable water and cooling towers. Suspect rank was assigned to 20 sources including large building water systems and cooling towers. CONCLUSION: Residential potable water, large building water systems and car travel appear to contribute to a substantial proportion of sporadic Legionnaires' disease. Cooling towers are also a potentially significant source; however, definitive linkage to sporadic cases proves difficult. The sources of sporadic Legionnaires' disease cannot be definitively identified for most cases.
BACKGROUND: Most Legionnaires' disease in the US and abroad is community-acquired and believed to be sporadic, or non-outbreak associated. Most patients are exposed to numerous water sources, thus making it difficult to focus environmental investigations. Identifying known sources of sporadic community-acquired Legionnaires' disease will inform future sporadic Legionnaires' disease investigations as well as highlight directions for research. The objective is to summarize and rank sporadic Legionnaires' disease sources based on the level of linkage between the environmental source and cases. METHODS: A PubMed search was conducted using the search terms legion* and (origins or source or transmission) and (sporadic or community-acquired). Studies of nosocomial and/or outbreak-associated disease were excluded from this review. Definite, probable, possible and suspect ranks were assigned to sources based on evidence of linkage to sporadic Legionnaires' disease. RESULTS: The search yielded 196 articles and 47 articles were included in the final review after application of exclusion criteria. A total of 28 sources were identified. Of these, eight were assigned definite rank including residential potable water and car air-conditioner water leakage. Probable rank was assigned to five sources including solar-heated potable water and soil. Possible rank was assigned to nine sources including residential potable water and cooling towers. Suspect rank was assigned to 20 sources including large building water systems and cooling towers. CONCLUSION: Residential potable water, large building water systems and car travel appear to contribute to a substantial proportion of sporadic Legionnaires' disease. Cooling towers are also a potentially significant source; however, definitive linkage to sporadic cases proves difficult. The sources of sporadic Legionnaires' disease cannot be definitively identified for most cases.
Authors: Candis M Hunter; Simone W Salandy; Jessica C Smith; Chris Edens; Brian Hubbard Journal: Public Health Rep Date: 2021-06-29 Impact factor: 3.117