Epidemiology of campylobacteriosis in a cohort of rural population near Calcutta.

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at monthly intervals. The overall diarrhoea attack rate was 19 episodes per 100 person-years with peak incidence in the 1- to 4-year-old age group (76/100 person-years). Eight (11.5%) of the total episodes were campylobacter-associated and the overall rate of campylobacter positive diarrhoeal episodes were 2.2 per 100 person-years. Of the 1002 stool samples from healthy individuals 32 (3.2/100 samples) were positive for campylobacter. The organism was most frequently isolated from children under 1 year of age both during diarrhoeal episodes (11.5 per 100 person-years) and non-diarrhoeal (11.1 per 100 samples). Multiple infections in a family were rare. In 19.4% of the occasions one or more animals were campylobacter positive. However, only in 7.7% of these occasions was a human infection recorded within 1 month after the animal was found to be positive. The study showed that the epidemiology of campylobacteriosis in this community was distinct compared to that observed in developed countries.