title: Legionnaires' disease outbreak in Rome, Italy.
abstract: Between August and October 2003, 15 cases of Legionnaires' disease were detected in the 9th district of Rome. To identify possible sources of Legionella exposure, a matched case-control study was conducted and environmental samples were collected. Hospital discharge records were also retrospectively analysed for the period July-November 2003, and results were compared with the same period during the previous 3 years. The case-control study revealed a significantly increased risk of disease among those frequenting a specific department store in the district (OR 9.8, 95% CI 2.1-46.0), and Legionella pneumophila was isolated from the store's cooling tower. Genotypic and phenotypic analysis of human and environmental isolates demonstrated that the cluster was caused by a single strain of L. pneumophila serogroup 1, and that the cooling tower of the store was the source of infection. The increased number of hospital admissions for microbiologically undiagnosed pneumonia during the study period may indicate that some legionellosis cases were not identified.
authors.affiliation: Centro Nazionale Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, Rome, Italy. Rota@iss.it
authors.forename: M C
authors.initials: MC
authors.lastname: Rota
authors.forename: G
authors.initials: G
authors.lastname: Pontrelli
authors.forename: M
authors.initials: M
authors.lastname: Scaturro
authors.forename: A
authors.initials: A
authors.lastname: Bella
authors.forename: A R
authors.initials: AR
authors.lastname: Bellomo
authors.forename: M O
authors.initials: MO
authors.lastname: Trinito
authors.forename: S
authors.initials: S
authors.lastname: Salmaso
authors.forename: M L
authors.initials: ML
authors.lastname: Ricci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D016952:Legionella pneumophila / Q000145:classification / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D014871:Water Microbiology; D014881:Water Supply