Trichinellosis Outbreak Linked to Consumption of Privately Raised Raw Boar Meat - California, 2017

On January 15, 2017, a hospital physician notified the Alameda County Public Health Department (ACPHD) in California of a patient with a suspected diagnosis of trichinellosis, a roundworm disease transmitted by the consumption of raw or undercooked meat containing Trichinella spp. larvae (1). A family member of the initial patient reported that at least three other friends and family members had been evaluated at area hospitals for fever, myalgia, abdominal pain, diarrhea, and vomiting. The patients had attended a celebration on December 28, 2016, at which several pork dishes were served, including larb, a traditional Laotian raw pork dish, leading the hospital physician to suspect a diagnosis of trichinellosis. Although the event hosts did not know the exact number of attendees, ACPHD identified 29 persons who attended the event and seven persons who did not attend the event, but consumed pork taken home from the event by attendees. The event hosts reported that the meat had come from a domesticated wild boar raised and slaughtered on their private family farm in northern California. ACPHD conducted a case investigation that included identification of additional cases, testing of leftover raw meat, and a retrospective cohort study to identify risk factors for infection.