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Paragonimiasis Reinfection Prevention — SCE Infectious Diseases MCQ

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EasyParasitologyParagonimiasis Reinfection PreventionSCE Infectious Diseases

A 50-year-old man from the Philippines develops chronic cough and haemoptysis. CXR shows bilateral lower lobe cystic lesions. Sputum examination reveals large operculated eggs (80–120 µm). He reports eating raw freshwater crabs. He is treated with Praziquantel 25 mg/kg TDS for 3 days. At follow-up, he asks about risk of reinfection. What counselling should be given?

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Correct answer: E — Avoid eating raw or undercooked freshwater crustaceans (crabs, crayfish) — this is the sole route of Paragonimus acquisition; cooking kills the metacercariae

Paragonimiasis (lung fluke) is acquired exclusively through ingestion of metacercariae in raw/undercooked freshwater crustaceans (crabs, crayfish). Prevention: cook all freshwater crabs/crayfish thoroughly before eating. There is no vaccine or chemoprophylaxis. The cultural practice of eating raw crabs (common in parts of East/South-East Asia) is the primary risk factor. Post-treatment follow-up includes repeat sputum examination at 3 months to confirm egg clearance. Reinfection occurs with re-exposure — lifelong dietary modification is needed in endemic areas.

Reference: WHO 2022 – Trematode guidelines; UKHSA 2023