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U. S. Trichinae Herd Certification Program

Livestock Update, December 2001

Valerie Tuck and C. M. Wood, Animal & Poultry Sciences, VA Tech

Trichinellosis (trichinosis) has been a worldwide threat for more than 150 years. At the beginning of the 20th century, 2.5% of U. S. pigs were infected with Trichinella spiralis, and one out of every six people in the U.S. was infected with this nematode parasite as well. Major changes have occurred in the past 50 years to decrease the number of human trichinellosis cases to fewer than 50 per year, many from bear and other wild game. Prevention of human trichinellosis through the ingestion of infected pork is accomplished by heating, irradiation, freezing, or curing the meat, and through consumer education. Swine can become infected with T. spiralis due to poor management, feeding raw waste products, and exposure to rodents, but there is essentially little risk of pigs acquiring this organism in modern pork production systems. There were fewer than 0.013% positive tests in 1995 and 0% reported in 1996 (Gamble, 2001).

Despite the rare occurrence of trichinellosis, many foreign markets block U. S. fresh pork imports because slaughter inspection for T. spiralis is not required (McBride, 2000). Recently, an innovative program for certifying trichinae-free pork has been created to ensure the absence of T. spiralis through good farm management. The Trichinae Herd Certification Program is a pre-harvest safety program that will document swine management practices that minimize the risk of T. spiralis. This is a joint project between the National Pork Board, the meatpacking industry, APHIS, and the Food Safety Inspection Service (Anon., 2000).

Pork producers volunteer to become part of the program by having their operations audited by an APHIS-accredited veterinarian. Few sites in the pilot program met all established criteria for a risk-free program, primarily due to the lack of a regular rodent control program. However, more than 85% of these sites could meet good production practice criteria with minor improvements. Pigs from the audited sites are slaughtered and each carcass tested through pooled sample digestion methods and ELISA testing (Anon., 2000). Certified veterinarians will conduct random audits to ensure good production practices remain in place to keep the farms and packing plants trichinellosis free.

According to Pyburn et al. (2001), the pilot program has proven successful, and the certification program will gradually be enlarged to encompass more of U. S. pork production, offering further assurances to consumers world wide of a safe supply of pork.


APHIS. 2000. Trichinae Herd Certification. Available at: Accessed Sept. 27, 2001.

Gamble, R. 2001. Pork Facts - Food Quality and Safety. Available at: Accessed Oct. 17, 2001.

McBride, J. 2000. Giving Pork a New Image. Agric. Res. Available at: Accessed Sept. 27, 2001.

Pyburn, D. G., H. R. Gamble, L. A. Anderson, and L. E. Miller. 2001. Verification of good production practices which reduce the risk of exposure of pigs to Trichinella. J. Anim. Sci. 79(Suppl. 1):46 (Abstr.).

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