Results
Postmortem examination revealed splenomegaly and severe congestion 2/2 (figure 1), enlarged and haemorrhagic lymphnodes 2/2 (figure 2), hepatomegaly and severe congestion ½ (figure 3a), white multi-focal patches on the liver ½ (figure 3b), globosed, severely congested, generalized cortical petechiae and severe blood clot in the pelvis 2/2 (figures 4a and b). Histopathological findings were thus: spleen: severe lymphocytes depletion (figure 5). Lymph node: severe lymphocytes depletion and severe hemosiderosis (figure 6). Liver: severe congestion with focal areas of coagulation necrosis (figure 7). Kidney: severe congestion and renal tubular and glomerular necrosis with few tubular proteins cast (figures 8a and b).
Viral isolation on the culture plate was revealed by haemadsorption. The presence of the virus typified by the attachment of large numbers of pig erythrocytes to the surface of infected cells thereby forming the rosette appearance (figure 9) as opposed to the negative wells which were not inoculated with the infected tissues (figure 10).
Gel picture (Figure 11) shows that DNA fragments of 278bp (confirming the presence of ASFV) were successfully extracted and amplified from the spleen, lymph node and kidney of the infected animals. Note that the size of the PCR products in lanes 1, 2, and 3, which were ASFV positive amplicons presented similar DNA fragment base pairs to the product of the positive control of ASFV in lane 4. The nucleotide sequences of ASFV generated from this study were deposited in the Genbank with accession numbers MN888963 and MN888964.
The result of phylogenetic analysis based on the p72 (B646L) gene is presented in figure 12. It shows the ancestral relatedness of the sequence from this study to other 53 sequences downloaded from the Genbank database, including those from Nigeria, different parts of Africa and beyond. Apparently, the sequence from this study failed to cluster with any other, including the ones from Nigeria. However, the closest relatives based on the phylogenetic analysis are sequences that make up the genotype-I ASFV group. These sequences were generated mainly from Nigeria, other countries (especially Western and Central Africa), and Europe. Consequently, the sequence from this study was considered to also belong to genotype-I ASFV.