Clinical and immunologic characteristics of vibrio cholerae o139 bengal infection in north american volunteers

Vibrio cholerae O139 Bengal has recently emerged as a cause of epidemic cholera in Asia. To evaluate clinical and immunologic responses to infection, V. cholerae O139 Bengal AIl837 was administered to healthy adult North American volunteers. Two of 4 persons ingesting 10⁴ cfu became ill (incubation period, 48 h; mean diarrheal stool, 1873 g), as did 7 of9 persons receiving 10⁶ cfu (incubation period, 28 h; mean diarrheal stool, 4548 g). III volunteers did not demonstrate a vibriocidal antibody response to the challenge strain or other V. cholerae. Three months later, volunteers were rechallenged with the homologous O139 Bengal strain. Only 1 of 6 persons who had been ill on initial challenge had diarrhea, compared with 11 of 13 controls (P=.01; protective 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 level of protection against subsequent disease is provided by initial clinical infection.