Cryptosporidiosis in children in Idukki District in southern India.

Concentrated stool samples from 560 children, aged from two weeks to 10 years, from Idukki District, southern India, were examined to detect Cryptosporidium oocysts, using a phenol-auramin stain and fluorescent microscopy. Smears of stool samples were also stained by a modified Ziehl-Neelsen method and were examined by light-microscopy. One sample was collected from each of 266 children with diarrhoea and 294 age-matched children without diarrhoea. Cryptosporidium oocysts were detected in 4.5% of all stools, in 6% of diarrhoeal stools and in 3% of stools from healthy controls. Results of the study show that Cryptosporidium infection is common in children with diarrhoea in southern India, and there is also a high frequency of asymptomatic cyst-passers in this area.