[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Trematodes (flukes)](https://durgical.com/en/microbiology/groups/trematodes/) › Fasciola hepatica [Microbiology](https://durgical.com/en/microbiology/) · [Trematodes (flukes)](https://durgical.com/en/microbiology/groups/trematodes/) # Fasciola hepatica - Parasite - Exam priority: medium A flatworm of livestock that reaches humans through raw watercress or other water plants. It tunnels through the liver and lives in the bile ducts. Updated 2026-11-01 Also called: sheep liver fluke, fascioliasis ## Key points - Raw watercress → fascioliasis. - Acute hepatic phase with marked eosinophilia; serology before eggs. - Large operculated egg. - Triclabendazole; praziquantel does not work. - Pseudofascioliasis from eating infected liver. ## At a glance **Shape** Flat leaf with a cephalic cone and oral and ventral suckers **Family** Fasciolidae **Type** Hepatic trematode (liver fluke), hermaphroditic **Size** Adult 2–3 cm ## Morphology - Large egg (130–150 × 60–90 µm), ellipsoidal, operculated and unembryonated. - Very similar to the Fasciolopsis buski egg. - Flat, leaf-shaped adult in the bile ducts. ## Transmission - Eating raw watercress or other aquatic plants carrying metacercariae. - Drinking water with floating metacercariae. - Not spread between people. **Reservoir:** Cattle and sheep (main); Other herbivores; Lymnaeid snails as intermediate host ### Isolation precautions What the care team adds to standard precautions. - Standard ## Life cycle - Unembryonated eggs leave in livestock or human faeces and mature in fresh water. - The miracidium infects a lymnaeid snail, where it multiplies (sporocyst, redia, cercaria). - Cercariae leave and encyst as metacercariae on aquatic plants such as watercress. - When the plants are eaten, the metacercaria excysts in the duodenum and crosses the wall to the peritoneum. - It pierces the liver capsule, migrates through the parenchyma and reaches the bile ducts. - In the bile ducts it matures and starts laying eggs after 3–4 months. ## Virulence factors - Acute phase: migration through the parenchyma destroys tissue and leaves haemorrhagic tracks. - Chronic phase: adults inflame and block the bile ducts. - Promotes stones, cholangitis, pancreatitis and fibrosis. - Ectopic migration to skin, lung or other organs. ## Diseases it causes - Fascioliasis, acute hepatic and chronic biliary - Acute cholangitis from biliary obstruction [Acute cholangitis →](https://durgical.com/en/conditions/acute-cholangitis/) ## Clinical picture - Acute phase: fever, right upper quadrant pain, tender hepatomegaly, urticaria and marked eosinophilia. - Chronic phase: intermittent biliary colic, jaundice, anaemia. - May be silent for years. ## Diagnosis - Serology (EIA confirmed by immunoblot): positive in the acute phase, before eggs appear. - Eggs in stool, duodenal aspirate or bile in the chronic phase. - CT with hypodense tracks in the liver; ERCP may show the flukes. - Pseudofascioliasis: eggs in stool after eating infected liver; repeat the test after avoiding liver. ## Treatment Triclabendazole is the drug of choice; praziquantel is not effective against Fasciola. Biliary obstruction may need ERCP. Drug class only; doses and regimens are set by the clinician from the current guideline. ## Prevention - Do not eat raw watercress or aquatic plants from areas with livestock. - Cook aquatic plants and use safe water. - Treat livestock and control snails. ## In Colombia An important livestock parasite in high Andean dairy regions (Boyacá, Cundinamarca, Antioquia, Nariño). Human cases are reported sporadically, probably underdiagnosed, and linked to eating watercress. ## Memory aid Raw watercress, tunnelled liver: Fasciola digs through the liver before it settles in the bile. ## Test yourself Think of the answer, then tap the question to see it. ## Which food typically transmits Fasciola hepatica? Raw watercress or other aquatic plants carrying metacercariae. ## Why is serology useful in acute fascioliasis? Antibodies appear at 2–4 weeks, before the fluke starts laying eggs. ## What is the drug of choice for fascioliasis? Triclabendazole; praziquantel is not effective against Fasciola. ## What is pseudofascioliasis? Finding Fasciola eggs in stool after eating infected liver, without real infection. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/microbiology/fasciola-hepatica/) ## Related - [Schistosoma mansoni / S. haematobium / S. japonicum](https://durgical.com/en/microbiology/schistosoma-mansoni-s-haematobium-s-japonicum/) - [Clonorchis sinensis / Opisthorchis spp.](https://durgical.com/en/microbiology/clonorchis-sinensis-opisthorchis-spp/) - [Paragonimus spp.](https://durgical.com/en/microbiology/paragonimus-spp/) ## Related conditions - [Acute cholangitis](https://durgical.com/en/conditions/acute-cholangitis/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. [← Back to the group: Trematodes (flukes)](https://durgical.com/en/microbiology/groups/trematodes/) Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [CDC - DPDx - Fascioliasis](https://www.cdc.gov/dpdx/fascioliasis/index.html) (CDC, 2019); [Foodborne trematode infections](https://www.who.int/news-room/fact-sheets/detail/foodborne-trematode-infections) (WHO, 2021); Parasitosis humanas (Corporación para Investigaciones Biológicas (CIB), 2019). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/fasciola-hepatica/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/fasciola-hepatica/