Black bear skewers make family sick with parasitic worms

(CNN) – It was supposed to be a celebration, but one family’s single meal of black bear meat sent several members to the hospital instead.

The celebration took place in the summer of 2022, according to the story in the latest edition of the U.S. Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report. An extended family – unnamed in the report – came from across the country to reunite in South Dakota.

A family member, a hunter, brought black bear meat he had harvested to northern Saskatchewan in May 2022. The hunter said the hunting outfitter recommended freezing the meat to kill any potential parasite.

The meat had been frozen for 45 days before being thawed, and the family would grill it with some vegetables and serve it as skewers.

Freezing can kill some parasites commonly found in black bears, but according to the World Organization for Animal Health, some species of parasites are tolerant to freezing.

Bears and other wildlife, including wild boars, wolves and squirrels, can often contract trichinellosis, a serious illness caused by parasitic roundworms of the genus Trichinella, but they often appear perfectly healthy. When butchering the meat, it would be difficult to know if it has been contaminated because there are few signs of a parasite.

Many wildlife experts advise bear hunters to consider any bear meat infected, and the CDC recommends cooking meat thoroughly to an internal temperature of at least 165 degrees Fahrenheit to kill parasites. Smoking, salting, drying and microwaving don’t always kill them, experts say.

The meat at the family gathering was initially served rare, but that was not the chef’s intention, the CDC said. On the contrary, it was “difficult for family members to visually determine the level of doneness” because the meat was dark in color. After some family members noticed it was undercooked, they put it back on the grill before serving it again.

It was only after returning home that some began to fall ill.

The first illness occurred in a 29-year-old man who required hospitalization twice over a three-week period. He reported symptoms of severe muscle pain and fever, and his eyes became swollen. Blood tests showed he had eosinophilia, a condition involving too many eosinophils in the body, signaling to doctors that a person might have allergies, cancer or parasites.

It was only during his second visit to the hospital that doctors learned the man had eaten bear meat and suspected he might have trichinellosis. Tests quickly confirmed that this was the case and tests were recommended for other family members.

Trichinellosis can be a mild or severe infection, and symptoms may depend on where in the body the larvae migrate. Mild infections may not have visible symptoms, according to the CDC. If the parasite enters the gastrointestinal tract, it can cause abdominal pain, diarrhea or vomiting. At the muscular level, it can cause fever, rash, conjunctivitis and facial swelling. Sometimes life-threatening symptoms can occur, including heart problems, central nervous system disorders, and breathing problems.

Among the eight family members interviewed by investigators, six had symptoms consistent with trichinellosis. Four had eaten bear meat and vegetables, but the other two had only eaten vegetables cooked with the meat. Three family members had to be hospitalized.

Those hospitalized received treatment for trichinellosis using albendazole, an antiparasitic drug. Those who were not hospitalized received only supportive care since their symptoms had resolved before it was determined they were infected. Since then, everyone has recovered.

During the investigation, CDC laboratories received samples of frozen bear meat and found Trichinella larvae, and the hunter was advised to discard any remaining meat. The CDC has also informed the Public Health Agency of Canada of the outbreak since the bear came from this country.

The CDC says it’s important that game meat — especially wild game harvested in northern latitudes — be cooked thoroughly.

Because meat contaminated with Trichinella can contaminate other foods, raw meat should be stored and prepared separately from other foods. The CDC also recommends that government agencies and private groups that organize or supervise hunting inform hunters about these risks and how to protect themselves.