A recent study out of Kansas State University has found that the African Swine Fever (ASF) virus can survive multiple freeze–thaw cycles and remain detectable in environmental samples, offering encouraging news for swine producers and diagnostic labs—particularly those operating in remote regions.
Dr. Jordan Gebhardt, Assistant Professor of Veterinary Medicine at Kansas State University, led the research team, which evaluated the virus’s detectability after samples were frozen, thawed, and re-frozen, then stored at 4°C (39.2°F). While some virus degradation occurred in feed dust and swine feces samples, the overall detection remained sufficient for diagnostic testing.
“We have more flexibility than we knew we had in the past,” said Dr. Gebhardt. “That’s a good thing if we’re in a remote location. We can store the sample at refrigerated temperatures and still get reliable diagnostic results.”
The findings are particularly relevant for producers and labs in regions where immediate sample shipping isn’t feasible. Traditionally, concerns about sample degradation led to strict protocols for rapid transport and minimal handling. This study suggests those constraints can be relaxed slightly without compromising test accuracy—especially in clean, non-organic samples.
Biosecurity Still Paramount
Despite the virus’s resilience, Dr. Gebhardt stressed that thermal treatments—especially extended holding periods at high temperatures—remain a key biosecurity strategy to limit ASFV spread via feed and other fomites. He acknowledged ongoing debate around the efficacy of heat treatments, but emphasized that in the absence of validated alternatives, they remain the industry’s best available defense.
ASF Challenges and Research Gaps
The research stemmed from real-world concerns in ASF-affected areas, including Vietnam, where partners in feed mills and field operations faced challenges in managing contaminated materials and testing logistics. Unfortunately, further research into ASF sample handling has been paused due to recent federal funding cuts.
Nevertheless, this new data offers a practical takeaway: ASFV DNA can survive freeze–thaw cycles, and with proper storage, diagnostic results remain accurate. That’s a meaningful insight for producers and veterinarians working under tough conditions or constrained logistics.
