DES MOINES, Iowa – Pseudorabies has been confirmed at an Iowa commercial swine facility. 

It is the first time since 2004 that a case has been confirmed in domestic swine. 

The USDA’s Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories confirmed pseudorabies at the facility on April 30. 

Pseudorabies is a contagious, infectious and often fatal herpes virus primarily affecting swine, which are the only natural hosts, according to APHIS. While eradicated from U.S. commercial herds in 2004, the virus persists in feral swine, causing reproductive failure, respiratory issues, high mortality in piglets, and remains a potential threat of exposure for domestic pigs.

Officials said the Iowa infection was traced to a Texas facility where swine were housed outdoors where they could have had contact with feral hogs. Swine from the Texas herd also tested positive for pseudorabies. 

APHIS, located at Iowa State University in Ames, is working closely with the Iowa Department of Agriculture and Land Stewardship in Des Moines, and the Texas Animal Health Commission in Austin, to conduct traceback efforts to better understand the detection, prevent further spread, and identify any additional potential exposures.

The Iowa facility had fewer then 100 pigs. It received five boars from the Texas facility. While the five boars tested positive, the remaining pigs on the Iowa site tested negative. 

Iowa Agriculture Secretary Mike Naig said he and other state animal health officials are “moving decisively” to eliminate the disease: “The Iowa Department of Agriculture and Land Stewardship has spent years preparing for these types of animal health events, and we have a strong, capable team in place to respond.

Naig and Iowa’s State Veterinarian Jeff Kaisand, DVM, said in a May 1 online news conference that about 100 pigs in the facility were destroyed to prevent further spread of the virus according to the guidelines of the American Veterinary Medical Association, with disposal taking place onsite, followed by disinfection.

Naig said the virus was detected through routine surveillance and only the five boars that came from Texas tested positive for pseudorabies: “We did not have any other additional positive tests outside of the five that were originally shipped from Texas, which gives us a strong indication that, given that there was no spread within the facility, there was no spread outside of the facility, either.”

Kaisand said testing would be done on all swine operations within a five-mile radius of the affected facility, with additional testing for those within a two-mile radius 30 days after cleanup is completed. While the virus was eradicated originally through vaccination, he said it is not appropriate to vaccinate herds now because the incident is isolated and contained.

Pat McGonegle, Iowa Pork Producers Association CEO, said state and federal officials expected the testing and related monitoring would involve 20 to 30 farms surrounding the affected area.

Anna Forseth, DVM, director of animal health at the National Pork Producers Council (NPPC) in Urbandale, Iowa, said, “The surveillance program was in place, the diagnostic laboratory reported timely results, the state veterinarian was notified and took swift action in conjunction with the state’s Department of Agriculture and the USDA, and traceability allowed for communication with the state of Texas, initiating a fast response there.

“While it is never ideal to have a case occur, the focus here should be that there is a known risk, and industry measures in place to swiftly coordinate and address that risk,” she added.

While the threat from feral swine remains a constant reality, APHIS said the combination of “robust diagnostic systems and proactive farm-level biosecurity provide a strong defense for the U.S. pork supply. Vigilance and strong biosecurity protocols ensure herds stay protected, and the export market remains secure.”

Naig said, “Iowa’s hardworking farmers lead the nation in pork production. It’s important for people to know that pseudorabies is not a food safety concern, and this virus does not pose a risk to consumers. The United States’ pork supply remains safe and secure, and we are committed to protecting animal health.”

Bryan Humphreys, NPPC CEO, said, “The officials in Iowa and Texas are administering the safety response protocols that we’ve talked about and put in place the last 22 years to ensure a rapid, effective disease response plan.”

Because pseudorabies is a reportable disease, APHIS said it has notified international trading partners, but the impact is expected to be minimal: “There is always a potential for trade disruption, which is why we moved so swiftly,” Naig said. “We anticipate minimal, if any, short-term trade disruptions.” APHIS added, however, there may be limited, short-term impacts on exports of U.S. swine and swine genetics.

Officials said they are not considering any restrictions on livestock exhibitions at this time.