Trichinellosis
Trichinellosis is infection with Trichinella spiralis larvae acquired from undercooked meat, especially pork or wild game, producing an initial intestinal illness followed by larval encystment in striated muscle causing myositis, periorbital edema, and eosinophilia. Diagnosis rests on eosinophilia and elevated creatine kinase confirmed by serology or muscle biopsy, and treatment combines an antihelminthic with corticosteroids for severe systemic disease.
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What this article covers
- Overview
A meat-borne nematode infection with two sequential phases: trichinellosis begins as an intestinal illness after ingesting Trichinella spiralis larvae in undercooked meat, then progresses to a…
- Epidemiology
Tied directly to meat consumption practices: cases cluster around ingestion of undercooked pork or wild game, with common-source outbreaks following a shared meal of infected meat.
- Risk factors
Consumption of undercooked pork or wild game meat: the essential exposure for infection; the greater the quantity of undercooked, larvae-containing meat eaten, the higher the risk and severity.
- Pathophysiology
Ingested encysted larvae are released in the stomach and mature in the small intestine: gastric acid and pepsin digest the surrounding muscle tissue, freeing larvae that invade the small intestinal…
- Clinical features
Initial intestinal phase (first 1-2 weeks): diarrhea, abdominal pain, nausea, and vomiting follow ingestion, corresponding to the intestinal invasion and maturation of adult worms.
- Differential diagnosis
Dermatomyositis/polymyositis: myalgia and muscle involvement, but lacks the meat-exposure history and eosinophilia, and is distinguished by autoantibody profile and biopsy showing perifascicular or endomysial inflammation without larvae.
- Diagnosis
Trichinellosis is confirmed by the combination of a compatible clinical picture (myalgia, periorbital edema, fever after undercooked meat ingestion) with eosinophilia and elevated creatine kinase…
- Management
First, start an antihelminthic as soon as trichinellosis is suspected or confirmed, ideally during the early intestinal phase before extensive muscle encystment.
- Complications
Myocarditis: the most feared complication, resulting from larval invasion of cardiac muscle, and a major driver of trichinellosis-associated mortality.
- Prognosis
Good with early treatment: most cases treated during the intestinal phase or early muscle-invasive phase, with or without corticosteroids for severe disease, recover fully.
- Prevention
Cook pork and wild game to an internal temperature of at least 145°F (63°C) for whole cuts (with a 3-minute rest) or 160°F (71°C) for ground meat, the threshold that reliably kills encysted Trichinella larvae.
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