D. Y. Aksoy1, U. Kerimoglu2, A. Oto3, S. Erguven4, S. Arslan1, S. Unal1, F. Batman1 and Y. Bayraktar1 Department of Internal Medicine, 2Department of Radiology, Hacettepe University School of Medicine, Ankara, Turkey, 3University of Texas Medical Branch at Galveston, Galveston, TX, USA and 4 Department ofMicrobiology, Hacettepe University School of Medicine, Ankara, Turkey
ABSTRACT Fascioliasis, caused by the liver ﬂuke Fasciola hepatica, is an infection that occurs worldwide, although humans are accidental hosts. F. hepatica infection comprises two stages, hepatic and biliary, with different signs and symptoms. Stool examination and ELISA can be used for the initial diagnosis. Radiographictechniques, such as computerised tomography and ultrasonography, as well as magnetic resonance imaging, are used widely for conﬁrmation and follow-up of the disease. Invasive techniques, such as percutaneous cholangiography, endoscopic retrograde cholangiography and liver biopsy, may aid in the diagnosis but are not essential. Triclabendazole is recommended as the ﬁrst-line agent for the treatment of F.hepatica infection, with bithionol as an alternative.
Keywords Diagnosis, Fasciola hepatica, fascioliasis, liver ﬂuke, treatment
Clin Microbiol Infect 2005; 11: 859–861
Fasciola hepatica is a trematode liver ﬂuke that infects primarily sheep, goats and cattle. The adult ﬂuke is large, ﬂat, brownish and leaf-shaped, and measures c. 2.5 · 1 cm. Large (140 · 75 lm) oval, yellow–brown, operculatedeggs are excreted in the faeces of infected animals and hatch into ciliated miracidia in water. To be infective, the miracidium must ﬁrst ﬁnd its intermediate host, which is a freshwater snail. Multiplication takes place within the snail, and cercariae with unforked tails emerge. The cercariae encyst on aquatic vegetation and develop into the metacercarial stage. The metacercaria are theningested by either normal hosts (sheep or cattle) or accidental hosts (humans). The metacercariae excyst in the intestine, perforate the intestinal wall, enter the peritoneum, and then pass through the liver capsule to enter the biliary tree. In the biliary tract, the mature ﬂuke releases eggs, which are once again excreted in faeces to complete the life-cycle . Human fascioliasis occurs worldwide,and there are signiﬁcant numbers of patients in eastern Europe, Iran, northern Africa and South America . F. hepatica infection has two different stages
Corresponding author and reprint requests: D. Y. Aksoy, Hacettepe University School of Medicine, Department of Internal Medicine, 06100 Sihhiye, Ankara, Turkey E-mail: firstname.lastname@example.org
with quite different signs and symptoms. The hepatic(ﬁrst, acute or invasive) stage of the illness occurs when the organism perforates the liver and begins to migrate through the liver parenchyma towards the biliary radicles. The onset of this stage occurs 1–3 months following ingestion of metacercariae. Fever, urticaria, pain in the right hypochondrium, hepatomegaly, hypergammaglobulinaemia and marked eosinophilia are the classical signs and symptomsof this stage. Mild hepatitis, severe subcapsular haemorrhage and frank hepatic necrosis can also be observed. A combination of the symptoms of absolute eosinophilia, fever and right upper quadrant pain should bring to mind the possibility of F. hepatica infection. The second or biliary stage usually presents with intermittent right upper quadrant pain with or without cholangitis or cholestasis.Eosinophilia can also be detected [3–5]. There are many different methods for the diagnosis of F. hepatica infection. Stool examination for ova and parasites can be used, but is often unrevealing during the ﬁrst stage. The method used most widely for diagnosis is an ELISA that detects antibodies against excretory–secretory antigen products from adult F. hepatica [6,7]. This assay has been...