Epidemiological patterns and incidence of bio-, sero- and phage types of XXXX in Hyderabad, India, during 1971-1984.

@entity3081 @entity1 @entity1838 @entity1902 @entity281
During 1971-1984 out of 44,762 @entity1902 cases bacteriologically examined, 4240 (9.5%) @entity1838 were isolated in Hyderabad, India. Out of them 1329 (31.3%) were classical and 2911 (68.7%) were el-tor biotypes. The changeover from classical to el-tor @entity3081 was observed in Hyderabad during 1975 and persisted. During this 14 year period four major outbreaks with @entity1838 serogroup O1 Ogawa, @entity1838 biotype el-tor serogroup O1 Ogawa were observed. Phage types 1, 2 and 4 were prevalent during the classical period and types 2 and 4 during the el-tor period. Of the @entity3081 @entity1 , 67% were under 30 years of age with no significant difference in the incidence among females (51.4%) and males (48.6%). The outbreaks were of protracted pattern with only few cases per day or week with peak incidence during monsoon (May-August). Community of the low socio-economic strata was the most susceptible group. Five zones situated at the outlet of the Moosi river in the downhill were recorded as extensive @entity3081 transmission zones and two of them were the primary foci of @entity281 . The severity of the @entity281 was found directly related to the average rainfall during the year leading to the sewage stagnation in the downhill.
