Trichinellosis is a parasitic disease transmitted through the consumption of meat from animals infected with Trichinella spp. nematodes. It is rare to see such cases, and when there are such cases in recent years, it is often associated with eating undercooked bear meat. This is the case reported in CDC MMWR where a group of family member gathering and ate bear kabobs.
"The and eight extended family members from three states (Arizona, Minnesota, and South Dakota) had gathered for several days in South Dakota and shared a meal that included kabobs made from the meat of a black bear (Ursus americanus), which had been harvested by one of the family members in northern Saskatchewan, Canada in May 2022. The hunting outfitter had recommended freezing the meat to kill parasites. The meat was frozen in a household freezer* for 45 days until being thawed and grilled with vegetables. 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. After some of the family members began eating the meat and noticed that it was undercooked, the meat was recooked before being served again. The family reunion concluded before onset of illness in the index patient."
"Although freezing kills Trichinella species commonly implicated in pork-associated outbreaks, freeze-resistant Trichinella species, including T. nativa and the T6 genotype (9), predominate in Arctic and sub-Arctic regions (6). Larval motility was observed in bear meat that had been frozen for nearly 4 months (110 days). Persons who consume game meat, especially that harvested in northern latitudes, should be informed that adequate cooking is the only reliable way to kill Trichinella parasites. Cooking wild game meat to an internal temperature of ≥165°F (≥74°C) is recommended by public health authorities**; temperatures should be verified with a meat thermometer. As demonstrated in this outbreak, the color of meat is not a good indicator of cooking adequacy. Safe handling of raw meat (i.e., separating raw or undercooked meat and its juices from other foods) is recommended to prevent trichinellosis; this investigation and previous investigations suggest that Trichinella-infected meat can cross-contaminate other foods"
What symptoms were exhibited?
Abdominal pain, diarrhea, myalgias (muscle pain), fever, eosinophilia (high white blood cell count) and periorbital edema (swelling around the eyes)https://www.cdc.gov/mmwr/volumes/73/wr/mm7320a2.htm
Outbreak of Human Trichinellosis — Arizona, Minnesota, and South Dakota, 2022Weekly / May 23, 2024 / 73(20);456–459
Shama Cash-Goldwasser, MD1; Dustin Ortbahn, MPH2; Muthu Narayan, DO3; Conor Fitzgerald, MPH4; Keila Maldonado5; James Currie, MD6; Anne Straily, DVM7; Sarah Sapp, PhD7; Henry S. Bishop7; Billy Watson, PhD7; Margaret Neja7; Yvonne Qvarnstrom, PhD7; David M. Berman, DO8; Sarah Y. Park, MD8; Kirk Smith, DVM, PhD9; Stacy Holzbauer, DVM9,10 (VIEW AUTHOR AFFILIATIONS)
Summary
What is already known about this topic?
Human trichinellosis cases in the United States are rare and are usually acquired through consumption of wild game.
What is added by this report?
Among eight persons who shared a meal that included the meat of a black bear harvested in Canada and frozen for 45 days, six trichinellosis cases were identified. The meat was grilled with vegetables and served rare; two cases occurred in persons who ate only the vegetables. Motile freeze-resistant Trichinella nativa larvae were identified in remaining meat frozen for >15 weeks.
What are the implications for public health practice?
Cooking meat to an internal temperature of ≥165°F (≥74°C) is necessary to kill Trichinella spp. parasites. Trichinella-infected meat can cross-contaminate other foods, and raw meat should be kept and prepared separate from other foods to prevent cross-contamination.
