Isospora belli infection as a cause of diarrhoea

A case of Isospora belli infection in Thailand is reported. An 18 month-old Thai girl from a foster home was hospitalized for acute mucous diarrhoea. Immature oocysts of I. belli were detected in the stool examination by simple saline smear. The symptoms subsided spontaneously with the disappearance of parasite from the stools on the fifth day. The pathogenesis of mucous diarrhoea and the route of transmission was discussed.