Epidemiological investigation of a legionellosis outbreak in a Slovenian nursing home, August 2010.

AbstractBackground: August 2010 marked the beginning of the largest outbreak of legionellosis in a Slovenian nursing home. This article presents our experiences with the outbreak investigation. Methods: In order to collect the necessary patient epidemiological data, we used individual epidemiological questionnaires. Samples were available from 15 patients and were subject to laboratory investigation. Urine and sputum samples were difficult to obtain due to the underlying diseases of the patients. Serological diagnostics constituted an important part of the epidemiological investigation. Sixty-four environmental samples were taken to identify the sources of infection. By genotyping, we assessed the affinity of the allelic profile of Legionella pneumophila serogroup 1 in environmental samples and in patient samples. Results: Legionnaires’ disease was diagnosed in 10 patients based on a combination of various tests. Legionella pneumophila serogroup 1, Legionella pneumophila serogroups 2–14, and Legionella sp...