Trichinella murrelli identified in red foxes (Vulpes vulpes) in Pennsylvania, USA

Authors: Dubey, Jitender; Thompson, Peter; DE ARAUJO, LARISSA - Orise Fellow; GUPTA, ADITYA - Orise Fellow; Kay, Sasha; Kwok, Oliver; BATTLE, JAY - Orise Fellow; VAN WHY, KYLE - Animal And Plant Health Inspection Service (APHIS); BROWN, JUSTIN - Pennsylvania State University; Rosenthal, Benjamin

Submitted to: Veterinary Parasitology: Regional Studies and Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2024
Publication Date: 7/25/2024
Citation: Dubey, J.P., Thompson, P.C., De Araujo, L., Gupta, A., Kay, S., Kwok, O.C., Battle, J., Van Why, K., Brown, J., Rosenthal, B.M. 2024. Trichinella murrelli identified in red foxes (Vulpes vulpes) in Pennsylvania, USA. Veterinary Parasitology: Regional Studies and Reports. 54(1). Article e101086. https://doi.org/10.1016/j.vprsr.2024.101086.
DOI: https://doi.org/10.1016/j.vprsr.2024.101086

Interpretive Summary: Trichinellosis (or trichinosis) is a parasitic disease occurring worldwide. Human trichinellosis has been known for more than two centuries; extreme cases can cause death. Uncooked pork was the main source of human infection until successful control efforts relegated most cases to consumption of wild game. Thirteen species/subspecies/genotypes of Trichinella have thus far been identified; of these, Trichinella spiralis poses the greatest risk as a human pathogen, given its ability to establish long-lasting and intense infections in pigs. Development of better farm practices has reduced Trichinella infections in domestic pigs to almost negligible. However, clinical trichinellosis continues to occur in the USA, mainly due to other zoonotic species of Trichinella in wildlife. Trichinella murrelli is the predominant species circulating in wildlife in the USA and is zoonotic Here. the authors report Trichinella murrelli first time in 7 of 21 red foxes (Vulpes vulpes) in Pennsylvania as a new host for T. murrelli. The persistence of transmission to wild carnivores highlights the need for continued vigilance for those consuming wild game, or consuming pork from farms where swine are raised in close contact with potential wildlife sources of exposure. This information will be of interest to biologists, wildlife scientists, hunters, parasitologists and veterinarians.

Technical Abstract: Trichinella infections have been eliminated from pork where pigs are raised in biosecure facilities, but wildlife infections persist. Trichinella murrelli is the primary zoonotic species in wild carnivores in the United States, having been identified in several species of omnivores and carnivores. Here, we document its occurrence in seven of 21 (33.3%) red foxes (Vulpes vulpes) from six counties in Pennsylvania. Encysted Trichinella larvae were detected in muscle squashes (<5 g samples) of all seven foxes, and in histological sections of the tongue and limb muscle of three. Larvae from muscle squashes were pooled and tested in a multiplex PCR capable of differentiating all Trichinella species native to the USA; all samples contained only T. murrelli. This is the first identification of T. murrelli in red foxes from Pennsylvania, and the first such survey performed in the last three decades. Results indicate that Trichinella remains endemic in Pennsylvania wildlife and a threat to the health of those who consume wild game.