[A community outbreak of Legionnaires' disease in Barcelona: epidemiologic and environmental study]

The investigation of the outbreak of legionellosis which developed in Barcelona in February 1988 included: 1) a case-control study, with the patients with Legionella pneumophila pneumonia (n = 56) and those with pneumonia by other organisms (n = 109) in the Hospital Clínic i Provincial (HCP); 2) a review of refrigeration towers and the water supply system; 3) a meteorological study, and 4) a survey of the construction works being carried out in the HCP area. The cases lived in the urban district 2 more often than the controls (odds ratio = 3.73, 95% confidence intervals 1.8-7.6), and were not associated with hospitals of hotels. L. pneumophila was not recovered from the environmental samples. The temperatures were unusually high, with a low air humidity. In the area near the HCP demolition materials were frequently removed. A causative focus was not detected; it cannot be ruled out, however, that the source of the outbreak was the removal of demolition materials in the affected area on the days preceding the epidemic outbreak.