Epidemiology of fascioliasis in the Koshi hills of Nepal.

Lymnaea auricularia race rufescens and Lymnaea luteola were shown to transmit F. gigantica in the Koshi hills of Nepal. The ecology of the snails was studied at nine different habitats in Hattikharka panchayat, the highest numbers occurring immediately after the end of the monsoon. Mature F. gigantica infections in the snails were detected from May to August and again in November. The prevalence of the infection in cattle was highest during the summer monsoon and in January and February. A control programme for fascioliasis based on these findings is suggested which requires that cattle be treated in February and possibly again in late August.