This article was originally posted at 7:36 a.m. CDT on Friday, May 1. It was last updated with additional information at 3:33 p.m. CDT on Friday, May 1.

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REDFIELD, Iowa (DTN) -- The USDA Animal and Plant Health Inspection Service (APHIS) confirmed Thursday cases of pseudorabies in a small commercial swine facility in Iowa, which traces to animals received recently from a herd in Texas. This is the first detection in commercial swine since its eradication in 2004.

Pseudorabies is a contagious viral disease in livestock and other mammals, but pigs are the only natural host because the others are resistant.

An enzyme-linked immunosorbent assay (ELISA) and latex agglutination test (LAT) performed at the National Veterinary Services Laboratory confirmed the detection of antibodies to pseudorabies virus following routine testing in the Iowa and Texas herds.

According to USDA's news release, "Initial traceback indicates that the five affected boars came from an outdoor facility in Texas. Animals from that herd also tested positive for pseudorabies. APHIS is working with officials in Iowa and Texas to expand traceback efforts and identify any additional potential exposures."

Iowa Secretary of Agriculture Mike Naig said the state is 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. We appreciate USDA APHIS, the Iowa State University College of Veterinary Medicine and Diagnostic Laboratory, pork producers and our industry partners for working together on this coordinated response," he said in a news release.

The initial positive test results were found on April 24 as a result of routine screening, Iowa's state veterinarian, Jeff Kaisand, said during a media call on Friday. The first screening was done at Iowa State University's Veterinary Diagnostic Lab. A plan was immediately put into action, and those samples were then sent to the National Veterinary Services Laboratory, also located in Ames. Additionally, the rest of the pigs at that central Iowa facility, which Naig said totaled less than 100 head, were also tested on April 26. Necropsies were done on April 27, and then coordination was done with the state of Texas for testing the herd of origin.

"The series of confirmatory tests were complete on Thursday (April 30)," Naig added. He said this appears to be an isolated incident, and all the other pigs at the facility tested negative.

Along with the positive test results, a surveillance zone was drawn with a 5-mile radius around the positive site. Other swine facilities in that zone will test for the disease within 15 days. Facilities within a 2-mile radius of the positive site will test a second time 30 days after the final cleanup is done.

"Every producer that's in that circle has been contacted by our office as of late in the day yesterday (April 30)," Naig said during the media call. "We are working very quickly to comply with all the regulations and standards around this, quickly to stamp it out, clean the site and remain disease-free."

While there is a vaccine for pseudorabies, which was used to eradicate the disease previously, Kaisand said the vaccine is not what needs to be used this time since it's an isolated incident and not widespread. There are currently no plans to restrict movement outside of the surveillance zone, and no trade implications are expected.

The disease is nearly always fatal in newborn piglets, attacking the central nervous system and causing tremors, seizures, and paralysis, as well as sneezing, fever, and coughing. Similar symptoms are seen in adult pigs, which can also have reproductive issues, causing failure to breed and abortions.

The disease had been eradicated in the commercial swine herd since 2004, yet is still present in feral hogs. It is believed that the affected Texas herd, which is housed outside, likely contracted the disease from the feral hog population.

"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," Naig added.

The positive Iowa site will be depopulated according to the guidelines of the American Veterinary Medical Association. Disposal will take place onsite, followed by disinfection. The Iowa officials stressed the importance of daily biosecurity to keep diseases such as this out of the commercial swine herd.

Texas officials have not commented about the status of the herd of origin.

Jennifer Carrico can be reached at [email protected]

Follow her on social platform X @JennCattleGal

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