Over a century of progress on Trichinella research in pigs at the United States Department of Agriculture: Challenges and solutions.

Trichinellosis, caused by 13 species/subspecies/genotypes in the nematode genus Trichinella, is a worldwide zoonosis. In the United States, trichinellosis was of historical and economic significance because of European restrictions on the import of U.S. pork. Before the advent of effective protective measures, most cases of trichinellosis were derived from consumption of undercooked or inadequately processed, infected pork. Research conducted at the United States Department of Agriculture (USDA) since 1891, and policies established by USDA regulatory agencies, have helped to reduce Trichinella infections in commercially raised domestic pigs to negligible levels. Here, we review the history of this scientific progress, placing special emphasis on research conducted at the USDA's Beltsville Agricultural Research Center.