A rural outbreak of Legionnaires' disease linked to visiting a retail store.
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.
Redd
S C
SC
Division of Bacterial Diseases, Centers for Disease Control, Atlanta, GA 30333.
Lin
F Y
FY
Fields
B S
BS
Biscoe
J
J
Plikaytis
B B
BB
Powers
P
P
Patel
J
J
Lim
B P
BP
Joseph
J M
JM
Devadason
C
C
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000302:isolation & purification; D016022:Case-Control Studies; D004196:Disease Outbreaks; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007875:Legionella / Q000276:immunology; D007877:Legionnaires' Disease / Q000453:epidemiology*; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D012424:Rural Population; D012988:Soil Microbiology; D014871:Water Microbiology
D000907:Antibodies, Bacterial