title: Escherichia coli O157:H7 outbreak associated with an improperly chlorinated swimming pool.
abstract: A cluster of gastrointestinal illnesses, including one case of hemolytic-uremic syndrome and one culture-confirmed Escherichia coli O157:H7 infection, followed a trailer park pool party. We interviewed a cohort of party attendees and park residents. A primary case was defined as the first gastrointestinal illness within a household between 5 July and 20 July in which the titer of IgG antibody to E. coli O157 (if determined) was elevated. Of 51 party attendees and trailer park residents, 18 developed a gastrointestinal illness, including 10 who met the definition of a primary case. Swimming in the pool significantly increased the risk of primary illness (relative risk = 6.3; 95% confidence interval = 1.8-18.9). No other exposure was significantly associated with primary illness, after pool exposure was controlled for. The implicated pool had little to no chlorine added during the period of 4-10 July. This outbreak provides new evidence of the importance of proper pool maintenance in controlling the spread of E. coli O157:H7.
authors.affiliation: Epidemic Intelligence Service, Notifiable Disease Unit, Atlanta, Georgia USA. jaisal@nm.net
authors.forename: M S
authors.initials: MS
authors.lastname: Friedman
authors.forename: T
authors.initials: T
authors.lastname: Roels
authors.forename: J E
authors.initials: JE
authors.lastname: Koehler
authors.forename: L
authors.initials: L
authors.lastname: Feldman
authors.forename: W F
authors.initials: WF
authors.lastname: Bibb
authors.forename: P
authors.initials: P
authors.lastname: Blake
mesh_terms: D002712:Chlorides; D004196:Disease Outbreaks; D004203:Disinfection / Q000592:standards*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000276:immunology; D019453:Escherichia coli O157 / Q000276:immunology; D006801:Humans; D013550:Swimming
chemical_list: D002712:Chlorides