The suspected existence of Schistosoma mansoni in Dhanusha district, southern Nepal.

Eggs resembling those of Schistosoma mansoni have been observed in human stools collected from the inhabitants of Dhanusha district, in southern Nepal. In an attempt to determine if S. mansoni was present, 518 sera collected from subjects from four sites in this district were checked for antibodies to this parasite, in July 1996 and May 1997, using ELISA. Overall, 94 (18.1%) of the subjects were deemed seropositive, with the highest seroprevalence (42.7%) at the one site in Chisipani village and the lowest (1.0%) at one of the three sites in Tulaschichauda village. A follow-up study of Chisipani village, in January 1998, indicated a seroprevalence then of 22.7% (37/110). Although possible intermediate hosts, clinical manifestations and geographical distribution have yet to be explored, the present results indicate that S. mansoni probably does exist in the Dhanusha district of Nepal.