AN EPIDEMIC OF CHOLERA DUE TO VIBRIO-CHOLERAE O139 IN DHAKA, BANGLADESH - CLINICAL AND EPIDEMIOLOGIC FEATURES

We describe the disease spectrum and socio-demographic and epidemiolog ical features of an epidemic of cholera due to a new pathogen, Vibrio cholerae O139, in patients attending a very large hospital in the metr opolitan city of Dhaka, Bangladesh. This hospital treats 70000-90000 p atients a year with diarrhoeal diseases. A 4% systematic sample of 185 4 patients attending from January to April 1993 were studied. Five hun dred and two (27%) of the 1854 patients were culture positive for V. c holerae O139 and 63 (3%) were culture positive for V. cholerae O1 biot ype El Tor. Patients with V. cholerae O139 were mainly adults with a, short history of watery diarrhoea. Eight-three percent of patients had moderate to severe dehydration. All recovered except one 80-year-old man with compromised renal function who died. Seventy-eight percent of patients required initial intravenous rehydration followed by oral re hydration therapy with rice ORS; they also received tetracycline to re duce diarrhoea severity. Most patients were from urban slums with inad equate sanitation facilities and hygiene practices. The newly recogniz ed V. cholerae O139 infection produced an epidemic of severe dehydrati ng diarrhoea indistinguishable from clinical cholera in a population w hich experiences two epidemic peaks of cholera in a year due to V. cho lerae O1. Infection with the latter does not appear to confer any cros s-protection from V. cholerae O139. The new pathogen suppressed, albei t temporarily, V. cholerae O1. Unlike other non-O1. serogroups of V. c holerae this new serogroup appears to have epidemic potential.