Fasciolosis

Abstract

AbstractFasciolosis is a zoonosis affecting ruminants, caused by the liver flukes Fasciola (F.) hepatica, and F. gigantica, which infect at least 2.4 million people worldwide. This disease may occur in cluster or family infections or after travel in high-risk areas such as the Nile Delta in Egypt, Iran, Turkey, South-East Asia, Mexico, the Caribbean and the Andean Altiplano. In Europe, fasciolosis occurs more frequently in Portugal, Spain and France, although autochthonous infections have also been reported from Ireland and Germany. Infectious metacercariae are ingested with contaminated water or raw or undercooked vegetables. During their larval stage immature flukes migrate through the liver producing an acute febrile syndrome some weeks after infection, followed by a chronic-latent stage which may last for years or decades. Acute fasciolosis is characterized by fever, high eosinophilia and hepatosplenomegaly. At this stage ova are usually not yet produced. Diagnosis relies on the detection of specific antibodies and/or antigens in serum. Typical imaging features include multiple, ill-defined, fleeting hypodense or hypoechoic areas in the liver. Intraabdominal bleeding due to fluke’s penetration of the bowel wall or liver capsule, may occur. In chronic latent fasciolosis the diagnosis is achieved by specific serology tests, detection of eggs in bile and parasitological examinations of multiple enriched stools samples. Ultrasonography may sometimes reveal a dilated and thickened common bile duct or crescent-like parasites in the gallbladder or bile ducts. Some patients exhibit sludge which typically does not sediment. Triclabendazole at a single dose of 10 mg/kg body weight is the treatment of choice.