A rural outbreak of Legionnaires' disease linked to visiting a retail store

• Published in: American journal of public health (1971) Vol. 80; no. 4; pp. 431 - 434
• Main Authors: Redd, S C, Lin, F Y, Fields, B S, Biscoe, J, Plikaytis, B B, Powers, P, Patel, J, Lim, B P, Joseph, J M, Devadason, C
• Format: Journal Article
• Language: English
• Published: United States Am Public Health Assoc 01.04.1990; American Public Health Association
• Subjects: Adult; Aged; Antibodies; Antibodies, Bacterial - isolation & purification; Case-Control Studies; Disease Outbreaks; Employees; Environmental Exposure; Female; Humans; Legionella - immunology; Legionella pneumophila; Legionnaires disease; Legionnaires' Disease - epidemiology; Male; Maryland - epidemiology; Middle Aged; Public health; Retail stores; Rural Population; Soil Microbiology; Water Microbiology; Maryland; United States > US
• ISSN: 0090-0036; 1541-0048
• DOI: 10.2105/AJPH.80.4.431

Between May 7 and June 7, 1986, 27 residents of a rural county in Maryland developed legionellosis, and two died. Legionella pneumophila serogroup 1 was cultured from the sputum of two patients and identified in lung tissue of a third patient by direct fluorescent antibody staining. An additional 11 patients had four-fold rises in antibody titer to L. pneumophila, and 13 had single titers greater than or equal to 1:256. To determine risk factors for disease, we performed a case-control study. Twelve of 16 case-patients reported visiting store A in the two weeks before onset of illness compared with four of 28 control-patients. A serologic survey of employees showed that employees of store A were 3.63 times more likely than control employees to have titers of antibody to L. pneumophila greater than or equal to 1:256 (95% confidence intervals 0.8, 16.7). Cultures of soil specimens, samples of water from the hot water system of store A and from stagnant ponds near store A collected five weeks after the end of the outbreak were negative for Legionella species. Store A was adjacent to a site of excavation and construction during May 1986, when the community was experiencing an extended drought. This investigation suggests that exposure to excavation and construction activity may be a risk factor for legionellosis.