Recurrent and persistent diarrhoea in a rural Zimbabwean community: a prospective study.

Prospective surveillance of patterns of diarrhoeal disease was conducted in a cohort of 204 young children living in a rural community in Zimbabwe. Trained field assistants recorded morbidity data obtained by weekly recall of mothers. Diarrhoea was defined by a commonly used local word, and a diarrhoea-free gap of three or more days was taken to signify a new attack. Diarrhoea was common in this study population with a peak incidence between 6 and 18 months of age. There was, however, wide individual variability in diarrhoea attack rates (range 0 to 20 attacks) during the 22 month study period. Whilst only 6 per cent of the recorded diarrhoea episodes were persistent (lasting longer than 14 days), a high proportion (26 per cent) of subjects had at least one attack of persistent diarrhoea (PD) during follow up. Children who had frequent attacks of acute diarrhoea also tended to have PD; PD was rare in those with few attacks. Thus, within this uniformly deprived African community, there were individuals who had a much higher susceptibility to diarrhoea compared to others. An understanding of this variability may point the way towards more effective interventions in the control of diarrhoeal disease.