What Is Trichinosis?

CDC says trichinellosis is a rare disease in the United States, with only about 15 confirmed cases per year compared with about 10,000 recorded cases a year worldwide, and that people who eat raw or undercooked pork or wild game, in particular bear, wild boar, wildcat, fox, wolf, seal or walrus, are at risk.

Symptoms come in stages. CDC lists nausea, diarrhea, vomiting and pain in the gut region after 1 to 2 days, followed after 1 to 2 weeks by fever and chills, swelling of the face, particularly the eyes, headache, weakness or tiredness, joint and muscle aches, itching or rash, cough, diarrhea and constipation.

Freezing is not enough for wild game. CDC says curing, drying, smoking or microwaving meat alone does not consistently kill the worms, and that freezing wild game, unlike freezing pork products, may not kill all of them because some species that infect wild game are freeze-resistant. A CDC MMWR report described six cases among eight people who shared black bear meat that had been frozen for 45 days and served rare, including two people who ate only the vegetables grilled with it, and another reported 10 probable cases linked to undercooked bear meat at a November 2023 gathering in western North Carolina.

The MMWR says adequate cooking is the only reliable way to kill Trichinella parasites in game meat, and that public health authorities recommend cooking wild game to an internal temperature of at least 165°F, or 74°C.