A new legionella species, Legionella feeleii species nova, causes Pontiac fever in an automobile plant.
The clinical, epidemiologic, microbiologic, and serologic characteristics of Pontiac fever were described in connection with an outbreak attributed to a new Legionella species, L-feeleii species nova. The outbreak occurred in two automotive engine assembly factories in Windsor, Ontario, during the period between August 17 and 21, 1981, when several production lines were shut down. The affected workers complained of headache, body aches, high fever, and extreme fatigue. The illness had an incubation period of 46 hours. The factories were serviced by several water coolant systems for the lubrication, cooling, and cleaning of the grinding and machining surfaces. These systems were checked weekly for total bacteria count and pH. A survey of 695 workers in one of the factories was performed to assess illness occurrence, severity, duration, symptoms, and medical history. A total of 317 workers satisfied the criteria for illness during the affected period. Departmental analysis of illness attack rates showed a decreasing progression from north to south, which was the direction of wind and air flow in the factory during the time in question. Environmental samples from the cooling systems were tested with a direct fluorescent antibody assay against a variety of Legionella species and Legionella like organisms. Serological samples from the workers were similarly tested. A Legionella like organism designated WO44C was isolated from a sample of coolant in the piston department and assessed for phenotype and antigenic characteristics and cellular fatty acid composition. The indirect fluorescent antibody testing of 28 ill workers was positive for WO44C. The authors note that this is the first known outbreak of a nonpneumonic legionellosis in which the etiologic agent is not serogroup-1 L-pneumophila. They propose the name L-feeleii species nova.