MANHATTAN, Kan. — A Kansas State Univ. veterinary researcher recently published a study on African Swine Fever (ASF) and how it could be spread through exported contaminated feed.

Megan Niederwerder, assistant professor of diagnostic medicine and pathobiology at Kansas State’s College of Veterinary Medicine, along with a research team, studied the risk of imported feed and how ASF could survive. Niederwerder tested the virus in a simulated 30-day transoceanic voyage in contaminated plant-based feed and ingredients.

“This study provides additional evidence supporting the potential risk that feed may play in the transboundary movement of African swine fever," Niederwerder said. “Our latest work provides robust half-life estimates, which include standard errors and confidence intervals, and characterizes the stages of viral decay over time for African swine fever virus in animal feed ingredients.”

The study showed that the half-life of ASF ranges from 9.6 to 14.2 days after exposure to varying temperature and humidity conditions simulating transoceanic shipment. This means a two-week transatlantic trip for feed under those conditions would result in the total viable virus concentration to decay by half its original count.

Niederwerder said all feed matrices provided a more supportive environment for viral stability when compared to media, where the shortest half-life was calculated.

"Transmission of swine viruses through feed has been recognized as a risk since around 2013, but the probability of African swine fever virus infection through plant-based feed was unknown until our publication earlier this year," she said. "Our research reports novel data and important quantitative information that can be incorporated into risk models for introduction and mitigation of African swine fever virus through imported feed ingredients."

ASF continues to spread throughout Europe and Asia. China, the world’s largest population of pigs, is estimated to lose 25 percent of the country’s production.

"African Swine Fever virus is a rapidly spreading and emerging transboundary animal disease that threatens pork production and human food security worldwide," Niederwerder said. "The emerging threat of African Swine Fever virus being introduced into the United States is staggering and significant efforts are focused on preventing entry."