A new publication in the journal Transboundary and Emerging Diseases entitled "Stability of African swine fever virus in feed during environmental storage" details the length of time ASFV remains stable in feed at different storage temperatures. The robust study was conducted by a research team led by Dr. Megan Niederwerder, Associate Director of the Swine Health Information Center.
"Previous estimates of ASFV stability in feed were based on fluctuating temperature and humidity conditions consistent with global trade," Niederwerder explained. "Novel data generated in the current study defines ASFV stability in feed at constant temperatures. This was an essential next step to guide holding-time recommendations for high-risk feed ingredients within feed mills and swine farms."
In the published study, the stability of ASFV Georgia 2007 was determined in three feed matrices, including complete feed, soybean meal, and ground corncob particles. After ASFV contamination, feed matrices were held at three environmental temperatures (cool storage at 40°F, ambient storage at 68°F, and hot storage at 95°F) for up to 365 days. Feed samples were tested throughout the 1-year period for ASFV genome detection on PCR and ASFV infectivity on cell culture and in swine bioassay.
Results demonstrate high stability of ASFV DNA in feed, with detection by PCR in almost all feed matrices throughout the conclusion of each study, including 365 days after ASFV inoculation when stored at 40°F and 68°F. Infectious ASFV was most stable in soybean meal, with the virus maintaining infectivity as determined by swine bioassay for at least 112 days at 40°F, at least 21 days at 68°F, and at least 7 days at 95°F.