Surveillance for Trichinella infection in U.S. pigs raised under controlled management documents negligible risk for public health

Authors: Gamble, Howard; HILL, DOLORES - Former ARS Employee; Fournet, Valsin; ADAMS, BRANDON - Former ARS Employee; HAWKINS-COOPER, DIANE - Former ARS Employee; FREDERICKS, JORRELL - Former ARS Employee; AQUINO, JOVAN - Orise Fellow; AGU, SONIA - Hispanic Association Of Colleges & Universities (HACU); CHEHAB, NADYA - Former ARS Employee; Ankrah Ankarah, Ako; ANTOGNOLI, MARIA - Animal And Plant Health Inspection Service (APHIS); REMMENGA, MARTA - Animal And Plant Health Inspection Service (APHIS); KRAMER, SCOTT - Animal And Plant Health Inspection Service (APHIS); GUSTAFSON, LORI - Animal And Plant Health Inspection Service (APHIS); Rosenthal, Benjamin

Submitted to: Food and Waterborne Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: The occurrence of Trichinella in pork once posed a major food safety risk, justifying efforts to control this parasite, but biosecurity measures preventing exposure of pigs to rodents, wildlife, and contaminated feed or waste products mitigate such risk. Compliance guidance for pork processors require assessment of the likelihood that Trichinella poses a public health risk, and perceived risk impedes international trade. Therefore, USDA researchers undertook a national survey of unprecedented scope to test for occurrence of Trichinella in pigs raised under the U.S. Pork Quality Assurance Plus (PQA+) program. They found no evidence of infection in any of 3,208,643 animals tested, providing 95% confidence that fewer than 1 in 1 million pigs raised under these production standards harbor such infections. These data will reassure Americans, and our trading partners, of the safety and quality of such pork, and will aid processors making labelling and processing decisions intended to mitigate Trichinella risk.

Technical Abstract: Previous studies have shown that pigs raised in controlled management production systems emphasizing biosecurity measures that prevent exposure to rodents, wildlife, and contaminated feed or waste products are not at risk for Trichinella infection. International food safety guidelines including the World Organisation for Animal Health and the Codex Alimentarius describe conditions for implementation and verification of controlled management pork production. When appropriately documented, pigs produced under these standards are considered to have a negligible risk for Trichinella. Here, we undertook a national survey to test for occurrence of Trichinella in pigs raised under the U.S. Pork Quality Assurance Plus (PQA+) program. A subset of U.S. pork plants that process pigs from PQA+ facilities voluntarily enrolled in this surveillance initiative. From 3,208,643 animals across twelve processing locations tested over a period of 54 months, we detected no Trichinella positives, providing a 95% confidence in a Trichinella prevalence of less than 1 in 1,000,000. Results obtained here should generalize to all PQA+ sources, as Trichinella exposure risk is based on production guidelines that extend to the larger PQA+ population.