title: Communitywide outbreak of Legionnaires' disease associated with a grocery store mist machine.
abstract: From 10 October through 13 November 1989, 33 patients were hospitalized with legionnaires' disease in Bogalusa, Louisiana. A case-control study revealed case-patients were more likely than controls to have shopped at grocery store A (93% vs. 52%; odds ratio [OR], 11.6; 95% confidence interval [CI], 2.3-78.7) in the 10 days before illness. Among those who shopped at grocery store A, case-patients were more likely to shop for greater than 30 min (OR, 18.0; CI, 2.0-407.8) and to buy produce items located close to an ultrasonic mist machine (OR, 7.4; CI, 1.3-56.2). Employees of grocery store A were more likely than employees of other grocery stores in Bogalusa to have antibody titers of greater than or equal to 1:128 to Legionella pneumophila serogroup 1 (Lp-1; relative risk, 2.9; CI, 1.3-6.8). Lp-1 was isolated from water in the reservoir of the mist machine. The monoclonal antibody subtype of the isolate was identical to organisms identified in two patients. Viable Lp-1 was isolated from mist produced by the machine. Aerosols from a grocery store mist machine were the source of this outbreak.
authors.affiliation: Epidemiology Section, Louisiana Department of Health and Hospitals, New Orleans.
authors.forename: F J
authors.initials: FJ
authors.lastname: Mahoney
authors.forename: C W
authors.initials: CW
authors.lastname: Hoge
authors.forename: T A
authors.initials: TA
authors.lastname: Farley
authors.forename: J M
authors.initials: JM
authors.lastname: Barbaree
authors.forename: R F
authors.initials: RF
authors.lastname: Breiman
authors.forename: R F
authors.initials: RF
authors.lastname: Benson
authors.forename: L M
authors.initials: LM
authors.lastname: McFarland
mesh_terms: D000328:Adult; D000336:Aerosols; D000368:Aged; D016022:Case-Control Studies; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000209:etiology; D008145:Louisiana / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D014871:Water Microbiology
chemical_list: D000336:Aerosols