African swine fever virus on abortus and false negative result of realtime-PCR

Abstract

African swine fever (ASF) has appeared in Viet Nam since February, 2019 and caused the huge
economic losses for the sector of pig husbandry. Up to now, the ASF epidemic has temporarily
passed, but ASF virus is still remaining in the pig herds, especially in the sow farms where the ASF
epidemic has happened. The sows did not show any specific clinic signs until miscarriage/absortion.
The result of RT-PCR tests for PRRS virus, classical swine fever virus, and PCR tests for Parvovirus
and Aujeszky’s virus on the foetus of abortion were all negative. However, the result of testing ASF
virus on 5 abortus samples from the different sows by conventional PCR procedure (OIE) in the
study were positive, while the result of parallel test for ASF virus according to the realtime-PCR (OIE)
procedure was negative. The research results allow us to confirm that ASF virus is circulating in the
sows in Viet Nam, and the false negative results of realtime-PCR test by (OIE) procedure for ASF
virus in the foetus of abortion samples were recorded.