Dave Pyburn, DVM, is the National Trichinae Coordinator for USDA’s Animal Plant and Health Inspection Services Veterinary Services.
Q What is Trichinella and how does it affect the pork industry?
A Trichinella spiralis is a nematode parasite. Swine, fox, wolf, bear, rat, dog, cat, raccoon, skunk, opossum and marine mammals are known reservoirs.
The life cycle proceeds when the larvae encysted in a host’s muscle is ingested by a warm-blooded animal. Digestion liberates the larvae from the muscle cysts. In the stomach and intestine, they reach the adult stage in three to six days. New larvae are produced and travel through the host’s circulatory system to striated muscle tissue where they encyst inside muscle cells. The larvae can remain there for up to 11 years. The life cycle begins again when a new host digests meat containing the larvae.
Swine are infected with Trichinella by consuming meat containing encysted larvae. The most common exposure modes are: Feeding uncooked waste containing meat scraps; consuming wildlife carcasses, including rats; cannibalism of infected swine carcasses.
Historically, human infection has been associated with eating undercooked pork. This has caused consumers to overcook pork or simply avoid eating it.
USDA’s National Swine Survey conducted in 2000 reported the infection rate in U.S. swine to be 0.007 percent. Modern swine management practices have virtually eliminated Trichinella in U.S. domestic pigs. Yet, it remains a public-perception issue.
With USDA’s Pathogen Reduction/Hazard Analysis Critical-Control Point program, meat processors will continue to require more information about on-farm production practices to ensure that they are in line with customers’ food-quality and safety-assurance demands. Many international trading partners require U.S. pork to originate from a carcass testing negative for Trichinella or to be frozen, cured or cooked, which inactivates of Trichinella.
Q Explain the Trichinae Certification Program.
A The National Trichinae Research Project began in 1994. This is an ongoing, collaborative effort between the National Pork Board, government – USDA’s Agricultural Research Service, Animal and Plant Health Inspection Services, Agricultural Marketing Service and Food Safety and Inspection Service – and allied industry. Through a series of scientific studies and pilot projects it has evolved into the Trichinae Certification Program.
This voluntary program’s objective is to provide information about Trichinella to pork producers. It provides standards for raising hogs to prevent exposure to Trichinella infection risk factors. For a perspective on what types of on-farm practices will be required, check out the article in the Profit Tips section within this issue.
The program will involve progressive levels: Stage I begins with enrollment and an animal audit; Stage II and III involve two levels of certification; finally there is the maintenance of the Stage III status.
Q When will the program be available to producers?
A The program’s regulations have been drafted and have moved into the government and public review process. This will take a year or so. I anticipate launching the voluntary Trichinae Certification Program in late 2003.
Q What is the producer’s implementation cost?
A Costs will be minimal for most producers because they already have many of the good production practices required for trichinae-safe certification in place. Producers will be responsible for paying an accredited veterinarian to conduct on-site audits; and they will pay a small fee to have those audits processed.
Q How will this program benefit the pork industry?
A In the U.S. domestic market, trichinae infection of pork products is very rare, but consumers’ perceptions remain a concern. Changing public perception requires education. But any educational efforts targeted at domestic and international consumers need to be supported by a process that validates the absence of the parasite from the pork supply.
Most production management systems used today have no or minimal risks that can be easily eliminated. This also allows for documentation and monitoring through a certification process. What’s more, the Trichinae Certification Program implementation steps will provide an infrastructure for tackling more complex on-farm quality-assurance and food-safety issues in the future.