leverflukken

Leverfluken, a Dutch term meaning liver fluke, refers to parasitic flatworms that inhabit the livers of mammals, including humans and livestock. The most clinically important species are Fasciola hepatica and Fasciola gigantica, which cause fascioliasis in animals and, less commonly, in humans. These organisms belong to the phylum Platyhelminthes and the class Trematoda. Their life cycle generally involves two hosts: freshwater snails as the first intermediate host and vegetation or water as the medium carrying metacercariae, which are ingested by the final host. After ingestion, immature larvae migrate through the liver tissue and mature in the bile ducts.

In animals, liver fluke infections can cause reduced weight gain, decreased milk production, liver damage, and biliary obstruction, leading to economic losses in livestock farming. In humans, infection occurs mainly through eating raw or undercooked aquatic plants, such as watercress, contaminated with metacercariae. The parasite migrates through the liver parenchyma, causing fever, right upper abdominal pain, hepatomegaly, and eosinophilia; chronic infection can result in biliary obstruction and cholangitis. Diagnosis is based on history, serology, imaging, and demonstration of characteristic eggs in stool or duodenal aspirates; however, egg shedding may be intermittent and stool tests can be negative in early disease. Serology and imaging (ultrasound, CT) aid in detection of the larval migration and biliary involvement.

Treatment typically relies on triclabendazole as the drug of choice, with alternative regimens available where access is limited. Prevention focuses on avoiding ingestion of contaminated vegetation, proper cooking of aquatic plants, controlling snail populations, and implementing livestock deworming programs to reduce transmission. Leverfluken are distributed worldwide, with higher prevalence in regions where livestock farming and freshwater snails are common; Dicrocoelium dendriticum is another liver-dwelling trematode with a somewhat different life cycle and epidemiology.