Parasites detected from diarrheal stool samples collected in Nepal.

Intestinal parasites were investigated in 396 diarrheal stool samples collected from individuals aged 1 to 68 years (males: 239 and females: 157) in Nepal. Samples were collected at different medical centers located in Kathmandu and from two public schools in a village setting in Kathmandu Valley and outside, during October 1999 to January 2001. The stool samples were mixed with 2% dichromate solution and transported to Japan for investigations. Parasites were detected by employing the formal-ether sedimentation technique. Of a total of 396 fecal samples investigated, 193 (49%) were positive for some kind of parasite. Altogether, 15 species of parasites were detected. Giardia intestinalis topped the list of protozoa, whereas Trichuris trichiura was the most frequently detected among helminth parasites. Of the 193 positive samples, 109 (56%) had single parasite infections, whereas 84 (43%) had multiple infections with a maximum of five species. Of the total positive, 45 (23%) had both protozoa and helminths whereas 37 (19%) had only protozoa. Females (52%) and children (15 years and under) (52%) had a marginally higher prevalence compared with males (46%) and adults (45%), respectively (p > 0.05). Samples collected from two public schools in a village setting inside Kathmandu Valley and outside had a significantly higher positive rate compared with those observed in individuals visiting different medical centers in the city and suburban areas in Kathmandu (p < 0.05).