LegionellaAntibodies in a Danish Hospital Staff with Known Occupational Exposure

Abstract

Although legionnaires' disease frequently is acquired in health care institutions, little is known about the occupational risk ofLegionellainfection among health care workers. The aim of the present cross-sectional study was to analyse antibody levels among exposed hospital workers and to determine the correlation between antibodies toLegionellaand self-reported symptoms. The study included 258 hospital employees and a reference group of 708 healthy blood donors. Hospital workers had a higher prevalence ofLegionellaantibody titres (1 : 128) than blood donors (odds ratio 3.4; 95% CI 2.4–4.8). Antibody levels were not higher among staff members at risk of frequent aerosol exposure than among less exposed employees. There was no consistent association between a history of influenza-like symptom complex and the presence of antibodies. The results indicate that hospital workers have a higher risk ofLegionellainfections than the general population. However, since no excess morbidity was associated with seropositivity, mostLegionellainfections may be asymptomatic.