PRRSV planned exposure and the law

Experts discuss different plan for dealing with porcine reproductive and respiratory syndrome
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In recent years, in light of limited success with vaccines for porcine reproductive and respiratory syndrome as well as mixed results with other control strategies, some veterinarians have started implementing a technique called planned exposure.

This practice, which involves injecting a swine herd with live strains of PRRSV, aims to stimulate active immunity by inducing subclinical to mild clinical disease. While the jury is still out on the merits of this practice, veterinarians who pursue planned exposure need to have legal and regulatory issues on their radar screen. Two speakers at the annual meeting of the American Association of Swine Veterinarians drove this message home.

Dr. Brian Erdahl, the investigative manager at the Center for Veterinary Biologics, Department of Agriculture, says that live strains of PRRSV, considered biologics, fall under the purview of his office. He says a practitioner must notify the Center for Veterinary Biologics prior to transporting live bacterial or viral agents. Notification allows the center an opportunity to assess the risk that the organism presents to animal health and the environment. Veterinarians who do not contact his office prior to transporting PRRSV to a farm may face regulatory action, including penalties of up to $1,000 and/or one year in prison per offense.

The movement of biologics is also regulated under the Animal Health Protection Act. This act was passed in 2002 to address deficiencies in some of the previous animal health regulations that made it difficult for agricultural officials to deal effectively with some of the current and emerging animal health issues.

The AHPA empowers federal officials with wide-ranging authority over the interstate movement of animals, organisms, and vectors. It allows the USDA to prohibit and restrict the movement in interstate commerce of any animal, article, or means of conveyance if the secretary of agriculture determines that the prohibition or restriction is necessary to prevent the introduction or dissemination of any pest or disease of livestock.

"The key word in this sentence is the word article," Dr. Erdahl said. A virus is classified as an article. Although the purposeful injection of swine with live PRRSV is intended to stimulate active immunity, the procedure, nonetheless, results in the dissemination of disease, and is subject to regulation under the AHPA.

The AHPA can also limit intrastate movement, but only really does so in extraordinary emergencies or in situations where state actions have been inadequate to control or eradicate a pest or disease. Under most circumstances, veterinarians are allowed to move a virus within a state. If they move a virus across state lines, however, they could be subject to penalties under the AHPA of up to five years in prison and $500,000. Repeat offenders could receive stiffer penalties of up to 10 years in prison.

The bottom line is that veterinarians should not transport PRRSV interstate, but intrastate transport is OK, as long as veterinarians inform the Center for Veterinary Biologics, Dr. Erdahl said. "Call, ask, and be in contact. That's the only way you can sleep well at night."

Even if veterinarians follow these rules, however, they still have to worry about legal liability. Veterinarians should be aware that a producer who is unhappy with the results of planned exposure could sue a veterinarian, says Tom Patterson, an attorney in Sioux City, Iowa. A veterinarian's conduct is often evaluated in light of a recognized standard of care exercised by other veterinarians, and planned exposure has not been established as mainstream practice. Just because there is a group of other veterinarians engaging in an experimental practice, doesn't mean you are protected. Customary practices of others are not a shield, Patterson says, and lawyers will most likely be able to find an expert who will argue that the practice was negligent. "Expert witnesses are a dime a dozen," Patterson said.

He doesn't recommend that veterinarians use planned exposure because of possible legal problems, but he says that veterinarians who choose to use it can take steps to minimize the risk of a lawsuit. "Have a conversation with your producers. Talk about expectations. Explain alternative products," Patterson said. "Draft an acknowledgement of risk (form)." He also recommends keeping records. "How do you make the stuff you inject?" Patterson questioned. "There is no standardization of this procedure."

Finally, veterinarians need to stay up-to-date with planned exposure efforts. "The reality is that people that fail with this procedure do not go out and brag about it," Patterson said. Veterinarians need to monitor the scientific literature, but realize that the published literature may not tell the whole story.