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: 7/22/2024
Citation: Gamble, H.R., Hill, D.E., Fournet, V.M., Adams, B., Hawkins-Cooper, D., Fredericks, J., Aquino, J., Agu, S., Chehab, N., Ankrah Ankarah, A.A., Antognoli, M.C., Remmenga, M.D., Kramer, S., Gustafson, L., Rosenthal, B.M. 2024. Surveillance for Trichinella infection in U.S. pigs raised under controlled management documents negligible risk for public health. Food and Waterborne Parasitology. 36. Article e00238. https://doi.org/10.1016/j.fawpar.2024.e00238.
DOI: https://doi.org/10.1016/j.fawpar.2024.e00238

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: Biosecurity measures preventing exposure of pigs to rodents, wildlife, and contaminated feed or waste products reduce the risk of zoonotic Trichinella infection in pork. To understand the benefits of such measures in the United States, we conducted the first comprehensive survey of pigs produced under the Pork Quality Assurance Plus production standard, surveying 3,208,643 pork samples from twelve processing locations tested over a period of 54 months. We detected no Trichinella sp. positives in any of these pork samples, providing a 95% confidence in a Trichinella sp. prevalence of <1 in 1,000,000 for the processors represented by the study. These results are consistent with international guidelines for having a negligible risk to public health. Results obtained here should generalize to all PQA+ sources, as Trichinella sp. exposure risk is based on production guidelines that extend to the larger PQA+ population.