Machakos Project Studies: agents affecting health of mother and child in a rural area of Kenya. VII. The incidence of diarrhoeal disease in the under-five population.

The outcome of three years of fortnightly diarrhoea surveillance of about 4000 children under the age of five is described. The two-weekly incidence of diarrhoea in children in the age group 0-5 months, 6-11 months and 12-23 months, who were reported and/or observed to be ill, was 3.4%, 5.6% and 3.4% respectively. A decline in the attack rates of diarrhoea not associated with measles at the end of 1975 and the beginning of 1976 corresponds with a similar decline in the incidence of measles and malnutrition. Initially diarrhoea information was only obtained from children who where reported and/or observed to be ill; later on, all mothers were questioned about their children's diarrhoea experience at the moment of the fieldworkers's visit or in the preceding two weeks. This yielded a four to sevenfold increase in diarrhoea incidence. Thus, diarrhoea appears to be a common condition among under-fives which is not necessarily considered to be an illness by the mother.