CHOLERA IN BAHRAIN - EPIDEMIOLOGICAL CHARACTERISTICS OF AN OUTBREAK

  • 1 January 1981
    • journal article
    • research article
    • Vol. 59  (1) , 61-66
Abstract
From 10 Aug., 1978-23 Jan., 1979, 913 culture-confirmed cases of cholera caused by Vibrio cholerae el tor, serotype Ogawa, occurred in Bahrain. The incidence of cholera reached a peak of 25-35 cases/day during the 7th wk of the outbreak (16-22 Sept.). The overall attack rate (27/10,000) was low; the outbreak subsided without mass immunization campaigns or rigorous border control of persons and imports. Investigation of 746 culture-confirmed cases that occurred in the period 10 Aug.-13 Oct. 1978 showed that cases occurred throughout most areas of the country and mainly affected infants, young children and adult working-age males. Symptoms were very mild; fewer than 20% of patients required specific rehydration therapy. The highest attack rate (84/10,000) occurred in infants < 1 yr of age. No common vehicle or mode of transmission was identified. A matched-pair study of 35 cases and controls showed that adult cases were more likely than controls to have consumed food or beverage outside of the home before becoming ill. V. cholerae was isolated from stored drinking water in the houses of 8 cases but not from numerous samples of food and tap-water. Cholera transmission probably occurred through a complex interaction of mild and asymptomatically infected persons with food, water and the environment.