ASF Virus Persists in Recovered Pigs, By Marty Misener from South West Ontario Veterinary Services

African swine fever (ASF) continues to be high on the list of transboundary diseases that can result in devastating damage to pork production. This devastating nature of ASF has sparked an unprecedented level of international collaboration. One example of this collaboration is the research partnership between the USA and Viet Nam. This collaboration benefits Viet Nam because it provides access to additional technical expertise and other resource in battling ASF. The USA benefits by gaining real world access to the disease control efforts in Viet Nam. Having “boots on the ground” allows for an accelerated learning curve involving diagnostics, vaccines and other control measures. Unfortunately ASF is persisting in Viet Nam. The number of pigs that recover from ASF infection depends on the strain of ASF that is involved. Although the percentage of infected pigs that recover is small it is not zero. These researchers wanted to evaluate the viral antigen distribution and lesions in recovered pigs post ASFV infection. Ten pigs that recovered from ASF at 6 weeks of age were monitored and assessed for anti-ASFV antibodies and viremia until slaughter. The five major organs (lung, liver, spleen, kidney, and lymph nodes) of these pigs were evaluated for microscopic lesions and viral antigen distribution.