Fasciola hepatica

Background

• Parasite: Fasciola hepatica
• "Liver fluke" or "Sheep liver fluke"
• Eggs in stool of infected mammals (sheep/cattle) → snail → aquatic vegetation → human
• Infected by eating raw watercress or water plants contaminated by immature larvae
• Immature larvae migrate from intestine → abdominal cavity → liver → bile duct (mature adult)

Clinical Features

• Nausea, vomiting, abdominal pain/tenderness, hepatomegaly
• Fever, rash, shortness of breath
• Marked peripheral eosinophilia
• Liver hematoma
• Chronic: Inflammation and obstruction of liver, gallbladder, pancreas
  • Biliary colic, cholangitis, cholelithiasis, obstructive jaundice
• Ectopic fascioliasis: Erythematous itchy nodules
• Pharyngeal fascioliasis: pharyngitis with edema, congestion, suffocation

Differential Diagnosis

• Amebiasis, larva migrans, cysticercosis, ascariasis, hepatitis, parasitic infection
• Biliary atresia, cholecystitis, cholelithiasis, cholestasis

Helminth infections

Cestodes (Tapeworms)

• Taenia saginata
• Taenia solium (Cysticercosis)
• Diphyllobothrium latum
• Hymenolepis nana
• Echinococcus granulosus

Trematodes (Flukes)

• Fasciola hepatica
• Fasciolopsis buski
• Opistorchis viverrini
• Schistosoma spp
  • Schistosomiasis
• Chlonorchis sinensis
• Paragonimus spp.

Nematodes (Roundworms)

• Ascaris lumbricoides
• Enterobius vermicularis (Pinworm)
• Filarial worms
  • Loa Loa
  • Onchocerciasis
  • Lymphatic filariasis (Elephantiasis)
    • Wuchereria bancrofti
    • Brugia malayi
    • Brugia timori
• Hookworm
  • Necator americanus
  • Ancylostoma duodenale
  • Cutaneous larva migrans (Ancylostoma braziliense)
• Dracunculus medinensis
• Strongyloides stercoralis
• Trichuris trichiura (Whipworm)
• Anisakis
• Toxocara spp.
• Trichinosis

Evaluation

• CBC: Leukocytosis, anemia, eosinophilia
• Elevated ESR and LFT
• Stool ova and parasites, culture
• Microscopy
• Endoscopy or surgery, biopsy
• Serology (ELISA), PCR
• CT abdomen, US, ERCP, cholangiography, MRI

Management

• Triclabendazole (10mg/kg PO x 1-2 days)
• Alternative: Bithionol and nitazoxnide
• ID and GI consult
• Possible surgery consult

See Also

• Parasitic diseases

References

• http://www.cdc.gov/parasites/fasciola/gen_info/index.html
• Leder K, et al. Liver flukes: Fascioliasis. In: Post T, ed. UpToDate. Waltham, Mass.: UpToDate; 2014. www.uptodate.com. Accessed December 24, 2014.
• Tolan RW, et al. (2013, Apr 12). Fascioliasis. eMedicine. Retrieved 12/24/2014 from http://emedicine.medscape.com/article/997890-overview

Authors

Ami Yamamoto, Ross Donaldson, Neil Young, Daniel Ostermayer