CLINICAL AND IMMUNOLOGICAL CHARACTERISTICS OF VIBRIO-CHOLERAE O139 BENGAL INFECTION IN NORTH-AMERICAN VOLUNTEERS

Vibrio cholerae O139 Bengal has recently emerged as a cause of epidemi c cholera in Asia. To evaluate clinical and immunologic responses to i nfection, V. cholerae O139 Bengal AI1837 was administered to healthy a dult North American volunteers. Two of 4 persons ingesting 10(4) cfu b ecame ill (incubation period, 48 h; mean diarrheal stool, 1873 g), as did 7 of 9 persons receiving 10(6) cfu (incubation period, 28 h; mean diarrheal stool, 4548 g). III volunteers did not demonstrate a vibrioc idal antibody response to the challenge strain or other V. cholerae. T hree months later, volunteers were rechallenged with the homologous O1 39 Bengal strain. Only 1 of 6 persons who had been ill on initial chal lenge had diarrhea, compared with 11 of 13 controls (P = .01; protecti ve efficacy = 80%). V. cholerae O139 Bengal can cause severe diarrhea typical of cholera, with clinical characteristics and a dose-response similar to those seen with V. cholerae O1 E1 Tor. A moderately high le vel of protection against subsequent disease is provided by initial cl inical infection.