Legionellosis in a Factory

Almost a year after Legionnaire's disease was first recognized among American Legion members attending a 1976 meeting in Philadelphia, the offending organism (Legionella pneumophila) was identified and its mode of transmission — inhalation of aerosols from contaminated water — was revealed. Although mortality was high, no secondary infections occurred. Main sources of the aerosols were cooling towers, shower heads, and building sites.

Now, epidemiologists describe a legionellosis outbreak that occurred during August–November of 2022 among 34 employees at a South Carolina factory. While several individuals had mild respiratory symptoms compatible with Pontiac fever (also caused by L. pneumophila), 15 required hospitalization and 2 deaths occu…