Stability of African swine fever virus on contaminated spray dried
porcine plasma
Abstract
African swine fever (ASF) is a viral disease that affects members of the
Suidae family. The notifiable disease is considered a major threat to
the pig industry, animal health, and food security worldwide. According
to the European Food Safety Authority, ASF virus (ASFV) survival and
transmission in feed and feed materials is a major research gap. Against
this background, the objective of this study was to determine the
survival of ASFV on re-contaminated spray dried porcine plasma (SDPP)
when stored at two different temperatures. To this means, commercial
SDPP granules were contaminated with high titers of ASFV in a worst-case
re-contamination scenario. Three samples per time point and temperature
condition were subjected to blind passaging on macrophage cultures and
subsequent haemadsorption test to determine residual infectivity. In
addition, viral genome was detected by real-time PCR. The results
indicate that heavily re-contaminated SDPP stored at 4°C remains
infectious for at least five weeks. In contrast, contaminated SDPP
stored at room temperature displayed a distinct ASFV titer reduction
after one week and complete inactivation after two weeks. In conclusion,
the residual risk of ASFV transmission through re-contaminated SDPP is
low, if SDPP is stored at room temperature for a period of at least two
weeks before feeding.