A community-wide outbreak of legionnaires disease linked to industrial cooling towers--how far can contaminated aerosols spread?

Abstract

A community-wide outbreak of legionnaires disease occurred in Pas-de-Calais, France, in November 2003-January 2004. Eighteen (21%) of 86 laboratory-confirmed cases were fatal. A case-control study identified smoking, silicosis, and spending >100 min outdoors daily as risk factors for acquiring the disease. Legionella pneumophila strain Lens was isolated from cooling towers, wastewater, and air samples from plant A. This unique strain matched all 23 clinical isolates, as assessed by pulsed-field gel electrophoresis subtyping. Modeling of atmospheric dispersion of aerosols emitted from plant A cooling towers showed good coverage of the communes where patients lived and showed that the dispersion extended over a distance of at least 6 km from plant A. No other aerosol-producing installation was identified as a plausible source, and no common source of indoor exposure was found. These findings implicate plant A as the most likely outbreak source and suggest that the distance of airborne transmission of L. pneumophila may be greater than previously reported.

• Authors: Tran Minh Nhu Nguyen, Daniele Ilef, Sophie Jarraud, Laurence Rouil, Christine Campese, Didier Che, Sylvie Haeghebaert, Francois Ganiayre, Frederic Marcel, Jerome Etienne, Jean-Claude Desenclos
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 193 Issue 1 Pg. 102-11 (Jan 01 2006) ISSN: 0022-1899 [Print] United States
• PMID: 16323138 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Aerosols

Topics

• Adult
• Aerosols
• Aged
• Aged, 80 and over
• Air Conditioning
• Air Microbiology
• Case-Control Studies
• Disease Outbreaks
• Female
• France (epidemiology)
• Humans
• Industry
• Legionella pneumophila (classification, genetics, isolation & purification)
• Legionnaires' Disease (epidemiology, microbiology)
• Male
• Middle Aged
• Risk Factors