Fascioliasis

Fascioliasis is caused by Fasciola hepatica and Fasciola gigantica. Ruminants are the natural hosts of these liver flukes. Human infection occurs following consumption of freshwater plants contaminated with the encysted metacercariae (commonly watercress and khat).

Disease is typified by fever and abdominal pain with a marked eosinophilia during the acute phase. Occasional sporadic outbreaks of Fasciola hepatica have occurred in the UK, although the majority of cases are imported.

Fasciolopsiasis is a similar disease caused by the fluke Fasciolopsis buski.

Detection of Fasciola hepatica, Fasciola gigantica and Fasciolopsis buski by microscopy

• Sample type: Standard stool sample – ova may be present in stool sample but are often scanty and may not be found in up to 30% of cases.
• Sample type: Whole worm – Please send fresh and do NOT add any fixative.

Detection of Fasciola hepatica by serology

• Sample type: A minimum of 0.5ml of serum is required (can be transported at room temperature).

Serology can be helpful and an IFAT test for antibody is available. The IFAT (screening titre 1/32) has given reliable results. It is species specific. In proven Fasciola hepatica infections the titre is in the order of 1/128. Serology is the best method of diagnosis in the early stage of the infection.

Patients with upper abdominal pain, thought to be hepatic, eosinophilia and fever, should be investigated.