Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 35-14: Fascioliasis + Key Features Download Section PDF Listen +++ ++ Infection results from ingestion of encysted metacercariae on watercress or other aquatic vegetables or in water Eggs of worm infect snails; snails subsequently infect vegetation Most prevalent in sheep-raising countries, particularly where raw salads are eaten + Clinical Findings Download Section PDF Listen +++ ++ Symptoms related to migration of larvae present 6–12 weeks after ingestion Typical findings Abdominal pain Fever Malaise Weight loss Urticaria Eosinophilia Leukocytosis Tender hepatomegaly and elevated liver function tests may be seen Migration to other organs may lead to localized disease (rare) Symptoms of worm migration subside after 2–4 months, followed by Asymptomatic infection by adult worms Intermittent symptoms of biliary obstruction, with biliary colic and, at times, findings of cholangitis + Diagnosis Download Section PDF Listen +++ ++ Eggs are not found in the feces during the acute migratory phase of infection Clinical suspicion should be based on clinical findings and marked eosinophilia in at-risk individuals Imaging studies Show hypodense migratory lesions of the liver In chronic infection, show masses obstructing extrahepatic biliary tract Serologic assays have sensitivity and specificity > 90%, but cannot distinguish past and current infection Antigen tests with excellent sensitivity and specificity are available in veterinary medicine and show promise in humans Definitive diagnosis is made by identifying eggs in stool Repeated examinations may be necessary + Treatment Download Section PDF Listen +++ ++ Praziquantel not effective Triclabendazole Treatment of choice Not available in the United States Standard dosing of 10 mg/kg orally in a single dose or two doses over 12 hours achieves a cure rate of about 80% Repeat dosing is indicated if abnormal radiologic findings or eosinophilia do not resolve Bithionol Second-line drug 30–50 mg/kg/day in three divided doses on alternate days for 10–15 days Not available in the United States Treatment with either drug can be accompanied by abdominal pain and other gastrointestinal symptoms Other potential therapies Emetine and dehydroemetine, both widely used in the past but quite toxic Nitazoxanide Prevention of fascioliasis involves avoiding ingestion of raw aquatic plants