Family infected with parasitic worms in US after eating bear meat, CDC says
Six people who shared a meal of black bear kebabs have been diagnosed with trichinellosis, a parasitic zoonotic disease.
In a new report Released this week, the Centers for Disease Control and Prevention (CDC) revealed that in July 2022, a 29-year-old hospitalized patient with suspected trichinellosis was reported to the Minnesota Health Department. His symptoms included fever, severe muscle pain, periorbital edema, or swelling of the eyes, and eosinophilia, or the condition of elevated levels of eosinophils, a type of white blood cell.
According to the report, a week before symptoms appeared, the patient and eight other people shared a meal that included black bear meat, which had been frozen for 45 days before being grilled and served rare with vegetables cooked with the meat.
An investigation into the incident found six cases of trichinellosis, including two in people who consumed only the vegetables. Trichinellosis is a parasitic infection caused by the larvae of trichinella, a type of roundworm. Usually, meat contaminated with the trichinella larvae comes from carnivorous animals such as bears, wild boars or walruses.
Molecular examination revealed that the bear meat larvae had been frozen in a household freezer for more than fifteen weeks and that the larvae were trichinella nativa, a frost-resistant species. The CDC warns that adequate cooking is the only reliable way to kill trichinella parasites and that contaminated meat can cross-contaminate other foods.
The CDC reports that he and eight family members from Arizona, Minnesota and South Dakota gathered in South Dakota for several days before the onset of symptoms in the first patient. During their meeting, they ate the meat of a black bear harvested by one of the relatives in northern Saskatchewan, Canada, in May 2022.
According to the report, the meat was “initially served ‘rare’ unintentionally, reportedly because the meat was dark in color and it was difficult for family members to visually determine the degree of doneness.”
It added: “After some family members started eating the meat and noticed it was undercooked, the meat was re-cooked before being served again.”
Three of the six symptomatic people, two of whom sought care at least twice before receiving treatment, were hospitalized. All three patients received trichinellosis-targeted treatment with albendazole, a drug used to treat a variety of parasitic worm infections.
All six symptomatic people recovered, with the CDC reporting that the non-hospitalized patients did not receive trichinellosis-targeted treatment because their symptoms resolved with supportive care alone.
Trichinellosis is rarely reported in the US. Most reported cases involve the consumption of wild game meat.
From January 2016 to December 2022, there were seven outbreaks of trichinellosis in the US reported to the CDC, including 35 probable and confirmed cases. Bear meat was the suspected or confirmed source of infection for most of these outbreaks, the CDC said said.