Epidemiological differences between cholera due to multiple antibiotic resistant and multiple antibiotic sensitive...

The appearance of cholera caused by multiply antibiotic resistant Vibrio cholerae in Bangladesh provided an opportunity to compare epidemiological features of infection caused by resistant and by sensitive V. cholerae. A prospective study was carried out using 46 families of hospital in-patient cholera cases due to resistant V. cholerae and 11 families of hospital cases due to sensitive V. cholerae and nine cases of cholera due to resistant and six cases due to sensitive V. cholerae detected in the neighbourhoods of hospital patients. All families were visited daily during ten days for cultures of rectal swabs, samples of domestic water and for history of diarrhoea. The results showed no significant difference in secondary infection and case rates in contacts of hospital cholera cases due to resistant and sensitive V. cholerae. However, the secondary infection rate (57%) in contacts of cases due to resistant V. cholerae detected from the neighbourhoods of hospital cases was significantly higher (p less than 0.05), than in the neighbourhood case-contacts (29%) of cases due to sensitive V. cholerae. The mean duration of diarrhoea in untreated resistant V. cholerae cases who were contacts of hospital cases (3.3 days) was significantly longer (p less than 0.05) than that of untreated sensitive V. cholerae (2.2 days). Higher isolation rates of V. cholerae were obtained from water sources used by cholera cases due to resistant V. cholerae, than from sources used by cases due to sensitive V. cholerae, but the differences were not statistically significant (p greater than 0.05). The study suggests that resistant V. cholerae poses an additional threat through a higher secondary infection rate and by causing illnesses of longer duration.