Fasciolopsiasis

Key Features

• Fasciolopsis buski is a common parasite of pigs and humans in eastern and southern Asia

• Eggs shed in stools and hatch in fresh water, followed by infection of snails and release of cercariae that encyst on aquatic plants

• Humans are infected by eating uncooked plants, including water chestnuts, bamboo shoots, and watercress

• Adult flukes mature in about 3 months and live in the small intestine attached to the mucosa, leading to local inflammation and ulceration

• Other intestinal flukes causing similar syndromes include two transmitted by undercooked freshwater fish

  • Heterophyes (North Africa and Turkey) species

  • Metagonimus (East Asia) species

Clinical Findings

• Infection is often asymptomatic, but eosinophilia may be marked

• In symptomatic cases, after an incubation period of 1–2 mo, manifestations include epigastric pain and diarrhea

• Uncommon findings

  • Other gastrointestinal symptoms

  • Ileus

  • Edema

  • Ascites

Diagnosis

• Diagnosis depends on finding characteristic eggs or, occasionally, adult flukes in the stools

• Moderate eosinophilia is common

• Illness > 6 months after travel to endemic area is unlikely

Treatment

• Praziquantel

  • Drug of choice

  • 25 mg/kg as a single dose

• Triclabendazole and niclosamide are alternatives (for most species)