The association of African swine fever virus with blood components of infected pigs.

The distribution of African swine fever virus (ASFV) in whole blood, plasma, red blood cells (RBC) and white blood cell (WbC) sub-populations was determined in pigs infected with virulent virus. Changes in the RBC and WBC populations were also examined. Total WBC counts decreased and RBC numbers remained unchanged during the course of the disease. The number of circulating lymphocytes decreased whilst neutrophil numbers increased owing to the replacement of mature forms by juveniles. Virus was present in all major blood fractions and was associated with equivalent numbers of both RBC and WBC. However, 90 per cent of the virus in whole blood was associated with RBC. Of the WBC subpopulations, virus was definitely associated with lymphocytes and possibly neutrophils.