Six people who shared a meal involving black bear meat 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 aches, periorbital edema or eye swelling, and eosinophilia or the condition of elevated levels of eosinophils, a type of white blood cell.
According to the report, a week prior to the symptoms appearing, the patient and eight other people shared a meal that included the meat of a black bear which had been frozen for 45 days before being grilled and served rare with vegetables that had been cooked with the meat.
An investigation into the incident found six trichinellosis cases, including two in people who consumed only the vegetables. Trichinellosis is a parasitic infection caused by the larvae of trichinella, a type of roundworm. Typically, meat contaminated with the trichinella larvae comes from carnivorous animals such as bears, wild boars or walrus.
Molecular testing found that larvae from the bear meat had been frozen in a household freezer for more than 15 weeks and that the larvae was trichinella nativa, a freeze-resistant species. The CDC warns that adequate cooking is the only reliable way to kill trichinella parasites and that infected meat can cross-contaminate other foods.
The CDC reports that six days before the symptom onset in the initial patient, he and eight extended family members from Arizona, Minnesota and South Dakota gathered in South Dakota for several days. During their gathering, they ate the meat from a black bear which had been harvested by one of the family members in northern Saskatchewan, Canada, in May 2022.
According to the report, 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”.
It added: “After some of the family members began eating the meat and noticed that it was undercooked, the meat was recooked before being served again.”
Three of the six symptomatic people, two of whom sought care at least twice before being offered treatment, were hospitalized. All three patients received trichinellosis-directed treatment with albendazole, a medication for the treatment of a variety of parasitic worm infections.
All six symptomatic people recovered, with the CDC reporting that the non-hospitalized patients did not receive trichinellosis-directed treatment because their symptoms had resolved with supportive care only.
Across the US, trichinellosis is rarely reported. Most of the cases that are reported relate to the consumption of meat from wild game.
From January 2016 to December 2022, there were seven trichinellosis outbreaks in the US that were reported to the CDC, including 35 probable and confirmed cases. Bear meat was the suspected or confirmed source of infection for the majority of these outbreaks, the CDC said.
