Two Related Occupational Cases of Legionella longbeachae Infection, Quebec, Canada

Several Legionella species can cause legionellosis, which results in influenza-like illness (Pontiac fever) or pneumonia (Legionnaires’ disease) (1,2). L. pneumophila, which is mainly transmitted from aerosolized water, has been the principal Legionella species reported from Canada (3). Unlike L. pneumophila, L. longbeachae is highly adapted to the soil environment and primarily transmitted from potting soils and compost (2). During summer 2015, a regional public health authority in Quebec, Canada, received reports of 2 cases of pneumonia attributable to L. longbeachae infection. These cases occurred 1 month apart in persons who shared the same workplace. We conducted epidemiologic and environmental investigations to identify the source of infection and propose appropriate control measures.