Infestations of clinical importance include those by Fasciola hepatica, Clonorchis sinensis and Ascaris lumbricoides.These parasites are trematodes and undergo both sexual (definitive host) and asexual (intermediate host) reproduction.
Patients may be asymptomatic or present with acute or chronic symptoms. Acute symptoms include a sudden onset of right upper quadrant pain, pyrexia or
cholangitis and symptoms of allergic reactions. Hepatosplenomegaly may be present. Chronic symptoms include intermittent biliary colic, cholecystitis, jaundice
anaemia and hypoproteinaemia.
Full blood examination may show eosinophilia. Liver function tests show features consistent with cholestasis. Stools are examined for the presence of ova. Specific
serological testing usually confirms the diagnosis.
The condition is treated by albendazole, praziquantel or bithional. Cholecystectomy and exploration of the common bile duct by ERCP may also be necessary.