A prospective study of acute diarrhoea in Finnish children from birth to 2 1/2 years of age.

To determine the incidence, clinical significance and etiology of acute diarrhoea in early childhood, a cohort of 336 children were followed from birth to the age of 24-32 (mean 26) months. More than half (55%) of the children had no diarrhoea, 26% had one episode and 19% had two or more episodes of diarrhoea during follow-up; altogether 248 episodes of diarrhoea were detected. Rotavirus was by far the most common (26%) identified pathogen; adenoviruses were detected in 4% and bacterial pathogens (EPEC, Salmonellae, Yersiniae) in 4% of the cases. Two thirds of the episodes remained etiologically unresolved. Rotavirus diarrhoea was significantly more severe than diarrhoea due to other causes; 75% of severe episodes of diarrhoea were associated with rotavirus. About two thirds of the infants were breast-fed over 6 months; breast-feeding for less than 6 months was associated with a higher incidence of rotavirus diarrhoea between 7-12 months of age but not thereafter. About three quarters of the children were cared for at home beyond 12 months of age; those at home had a lower rate of rotavirus diarrhoea than those at day-care centers.