Genetic diversity of African swine fever virus isolates from soft ticks (Ornithodoros moubata) inhabiting warthog burrows in Zambia.

The genomes of African swine fever virus isolates collected from soft ticks (Ornithodoros moubata) inhabiting warthog burrows in four areas of Zambia were compared by restriction enzyme site mapping. Isolates from different areas showed considerable diversity. The regions of genomes that differed between isolates were distributed throughout the virus genome, although some more conserved regions were identified, such as the right-hand third of the genome. The genomes of seven isolates from neighbouring warthog burrows within Livingstone Game Park in southern Zambia were more similar to each other than those from different areas. However, a number of differences were observed even between the genomes of isolates from the same warthog burrow. The variation between these latter isolates probably resulted from point mutations located at various positions along the genome, in addition to small additions or deletions at both terminal regions. Restriction enzyme site mapping indicated that one isolate may have originated by earlier recombination between two distinguishable viruses.