Comparative Analysis of Clinical and Biological Characteristics of African Swine Fever Virus Isolates from 2013 Year Russian Federation

Domestic pigs were inoculated with 50 (low) or 5000 (high) haemadsorbing doses (HAD50) via intranasal (IN) or intramuscular (IM) routes, to investigate the pathogenesis of 5 Russian isolates of African Swine Fever Virus (ASFV) collected in 2013. Several clinical and virological parameters (including hemorrhagic syndrome, body fever and gross and microscopic lesions) were identical between the high and low dose groups for all 5 isolates, whereas duration of pyrexia, incubation period and clinical phase of infection differed between the high and low doses and between the 5 isolates. Additionally, pigs inoculated with high ASFV doses had the shortest mean survival time. A subsequent contact challenge experiment demonstrated that IN- and IM-inoculated pigs were able to transmit ASFV via direct contact with non-infected pigs.

Finally, our experiments indicated that these Russian ASFV isolates possessed variable pathogenicity. The isolates from wild boars had the lowest virulence and extended disease duration as compared to those from domestic pigs.