Family Members Infected With Parasitic Worms After Eating Undercooked Bear Meat at Reunion

Six people became infected with parasitic roundworms after eating undercooked bear meat at a family reunion in South Dakota two years ago, according to a new report from the Centers for Disease Control and Prevention (CDC).

Extended family members from Arizona, Minnesota and South Dakota gathered for a meal in July 2022. One person brought meat from a black bear he’d hunted in Saskatchewan, Canada, in May of that year. The meat had been frozen for 45 days, upon the advice of the hunting guide, who’d recommended stashing it in the freezer to kill any parasites.

At the reunion, the meat was thawed, grilled up with vegetables and served as kabobs. When the family members started eating, they realized the meat was undercooked, so they tossed it back on the grill for a little longer before chowing down.

“The meat was initially inadvertently served rare, reportedly because the meat was dark in color, and it was difficult for the family members to visually ascertain the level of doneness,” according to the CDC.

Six days later, a 29-year-old man who’d attended the family reunion came down with a fever, swelling around the eyes, severe muscle pain and other symptoms. He was hospitalized twice, and during his second hospitalization, doctors learned that he’d recently eaten black bear meat. They suspected trichinellosis, a parasitic infection caused by Trichinella, a type of roundworm. Laboratory testing confirmed their hunch.

Five other family members also came down with trichinellosis, including two people who had not eaten the black bear meat but had eaten the vegetables. That’s because meat that’s infected with Trichinella can cross-contaminate other foods, per the CDC.

When the agency tested some of the remaining frozen black bear meat, it found Trichinella larvae from a species that can survive freezing. At that point, the meat had been frozen for 110 days—nearly four months—and the larvae were still alive.

In total, the infection sent three family members to the hospital, where they were treated with albendazole, an anti-parasite medication. The other family members who did not go to the hospital did not receive treatment, because their symptoms resolved on their own. All six sickened patients, ranging in age from 12 to 62, eventually recovered.

The outbreak doesn’t present a broader threat to public health. But the CDC is reminding home cooks to heat wild game meat to an internal temperature of at least 165 degrees Fahrenheit, especially if the meat came from northern latitudes.

The Massachusetts Division of Fisheries and Wildlife recommends keeping the thickest part of the meat at 165 degrees Fahrenheit for at least three minutes, or cooking to 170 degrees to be extra safe.

“Cook until there is no trace of pink meat or fluid, paying close attention to the areas around joints and close to the bone,” according to the state agency.

While freezing can kill some species of Trichinella commonly found in pork, “adequate cooking is the only reliable way to kill Trichinella parasites,” according to the CDC.

Cooks should always verify the temperature with a meat thermometer, because “bear meat is often dark purple in color, so if you’re not used to cooking bear meat, it can be hard to judge when it’s done or not done,” says Douglas Clark, an environmental scientist at the University of Saskatchewan in Canada, to CBC News’ Pratyush Dayal.

The CDC also advises keeping raw meat and its juices separate from other foods.

Trichinellosis infections are uncommon in the United States, and most cases result from eating wild game. Between January 2016 and December 2022, the CDC recorded 35 probable and confirmed cases from seven outbreaks, the majority of which were traced back to bear meat.

Worldwide, it’s a bigger problem, with an estimated 10,000 human infections per year, according to the World Organization for Animal Health. Most cases around the world result from eating the meat of domestic pigs or wild boar that hasn’t been cooked properly.

Sarah Kuta | READ MORE

Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.