Family infected with brain worms after eating undercooked bear meat, CDC says

Six people became infected with a parasite known as ‘brain worms’ after eating undercooked black bear meat, or food cross-contaminated with the meat, during a family reunion in 2022 – according to the Center for Disease Control (CDC) in a new report.

In May 2022, a group of nine family members met in South Dakota and shared kebabs made from black bear meat and vegetables. Earlier that month, one of the family members harvested the meat in northern Saskatchewan, Canada.

On the advice of a hunting outfitter, the relative froze the meat in a household freezer for 45 days to kill parasites. The family then thawed the meat and grilled it along with the vegetables, the CDC said.

However, the meat was accidentally served undercooked. Months later, family members presented to doctors or hospitals with symptoms consistent with the parasitic infection trichinellosis, also known as brain worms.

After health officials reported the infection, the CDC investigated. Now the health department is reminding people to cook their meat to an internal temperature of ≥165°F (≥74°C).

Muscular trichinella (Getty Images)Muscular trichinella (Getty Images)

Muscular trichinella (Getty Images)

Some states, such as Minnesota, require health care providers to report cases of trichinellosis to the Department of Health.

Healthcare providers did just that in July 2022 when a 29-year-old man presented to a hospital with symptoms consistent with trichinellosis: fever, severe pain, swollen eyes, and a high white blood cell count, among other abnormal labs.

It was the second time the man was hospitalized and the fourth time he sought care for his symptoms, which began in early July. Only then did he let healthcare providers know that he was eating bear meat.

Trichinellosis is a relatively rare parasitic disease that is usually caused by eating rare or undercooked meat from wild animals. Parasites, known as roundworms, infect parts of the body and reproduce, causing disease.

About 90 percent of cases in the United States come from bears.

Black bear (Getty Images/iStockphoto)Black bear (Getty Images/iStockphoto)

Black bear (Getty Images/iStockphoto)

During the May 2022 family gathering, only five of the nine family members ate the bear meat, while eight ate the vegetables it was cooked with.

Those who consumed the bear meat acknowledged that it was undercooked after consuming it. They reported that it was difficult to tell if it was properly cooked before eating because of its dark color. They put the bear meat back on the grill to cook after realizing it was rare, but it was too late.

After investigating, the CDC found that six of eight people, including the man who was hospitalized, had symptoms consistent with trichinellosis — four who ate the meat and two who consumed only the vegetables. Their ages ranged from 12 to 62, with one living in Arizona, four in Minnesota and one in South Dakota.

Three people required treatment aimed at trichinellosis, but two others recovered independently.

Tests carried out on the bear meat, which had been frozen for 110 days in the household freezer, revealed frost-resistant trichinella larvae. The person who had the meat was told to throw it away.

The CDC recommends that the best way to prevent trichinellosis is to cook meat thoroughly and use a meat thermometer to ensure it is done.

In addition, those handling raw meat should wash their hands with warm water and soap before preparing it, and thoroughly clean all utensils used after use.

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