Update on Hepatobiliary and Pulmonary Flukes

Hepatobiliary and pulmonary trematodes continue to cause significant morbidity and mortality worldwide. This article provides a selected update on the clinical features, diagnosis, immunology, treatment, and control of infections caused by Clonorchis sinensis, Opisthorchis species, Fasciola hepatica, and Paragonimus species. Although recent molecular studies have elucidated novel mechanisms of immune evasion in Paragonimus westermani and F. hepatica, there are no immediate prospects for a vaccine for any of these trematodes. Although treatment of paragonimiasis, clonorchiasis, and opisthorchiasis was simplified with praziquantel in the 1980s, eradication of fascioliasis remains difficult because of the limited availablity of bithionol. Several experimental drugs have been tested as possible alternatives. Despite successful pilot public health programs designed to decrease transmission of these trematodes, their prevalence remains high and underlines the importance of allocating resources to control them.