A COMMUNITY EPIDEMIC OF ENTEROPATHOGENIC ESCHERICHIA COLI O126:B16:NM GASTROENTERITIS ASSOCIATED WITH ASYMPTOMATIC RESPIRATORY INFECTION

Abstract

A 15-month surveillance was conducted at a metropolitan hospital for detection of enteropathogenic Escherichia coli (EEC). Of the 383 admissions, 151 cases of gastroenteritis (39.6%) were due to EEC as determined by the fluorescent antibody (FA) method. During the late summer of 1962, the O126:B16:NM strain was unusually prevalent, having been detected in 39 of the 82 cases (47.5%) of EEC enteritis. Epidemiologically, the outbreak was localized in three geographically distinct areas. Age and race specific rates for infants hospitalized with O126:B16:NM enteritis from these areas were 73.2, 54.5, and 118.2 per 1,000 population. Age and race specific attack per 1,000 population for all gastroenteritis in the clinic population and hospitalized patients were 177.2 and 30.3, respectively, with 31.7% due to EEC. In the nonwhite population, 0-3 months of age, 13% of the infants were hospitalized for gastroenteritis of which 53% was caused by EEC. In three selected hospital populations, 6 of 270 surveyed infants were asymptomatically infected with EEC, an incidence of 2.2%. In a community investigation, 50% of index households had one or more asymptomatic pharyngeal carriers of strain O126:B16:NM, while next-door neighbor households and distant community control households had pharyngeal carrier rates of 33 and 0% respectively. Intestinal carriage rates in these three groups were 18%, 3%, and 0%, respectively. Follow-up studies in pharyngeally infected neighbor households in which no members were intestinal carriers of EEC revealed on subsequent examinations six previously uninfected individuals became infected in four of five households examined. This implies a respiratory transmission of EEC.