Fasciola hepatica Infection in the United States

Fascioliasis is a worldwide infection caused by the liver fluke, Fasciola hepatica. In the United States, fascioliasis is an uncommon infection and is mainly reported among the immigrant population. Fasciola hepatica infection comprises 2 distinct stages (hepatic and biliary) and manifests mainly as abdominal pain, elevated liver enzymes, and eosinophilia. Enzyme-linked immunosorbent assay (ELISA) testing is sensitive for both stages while stool exams for F. hepatica eggs are positive only in the biliary stage. Radiographic findings using computed tomography and ultrasonography are not specific but support the diagnosis. Endoscopic retrograde cholangiopancreatography (ERCP) has been increasingly used to diagnose F. hepatica and to remove the adult fluke from the biliary tree. Triclabendazole is currently the recommended drug for treating F. hepatica infection. The rarity of the disease in the United States can result in a delayed diagnosis and sometimes in mismanagement. Physicians should consider this infection in patients with abnormal liver function and peripheral eosinophilia, especially in the immigrant population.