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

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.