Molecular characterization of African swine fever viruses from Burkina Faso, 2018

Background: African swine fever (ASF) is a viral hemorrhagic disease of domestic and wild swine. ASF has been endemic in Burkina Faso since 2003. In October 2018, substantial pig deaths occurred in Ouagadougou and two neighboring municipalities in central Burkina Faso. Following these mortalities, the veterinary extension services carried out investigations to begin control measures and collect samples. Methods: We performed real-time PCR for diagnostic confirmation and molecular characterization of the virus based on the partial P72, the complete p54, the partial CD2v, and partial B602L genes. Results: The field study revealed that mortalities started two weeks before our investigations. The real-time PCR results confirmed ASFV DNA in twenty samples out of sixty-two blood samples collected in four different locations. The sequencing and phylogenetic analysis showed that ASFVs causing these outbreaks belong to genotype I and serogroup 4. The study of the CVR showed 4 TRS variants, and that of the CD2v amino acid sequence revealed five variants based on the number of deleted KCPPPK motifs in the C-terminal proline-reach region of the protein. Conclusions: The existence of multiple variants in these outbreaks shows the importance of molecular characterization to understand the evolution of ASFV isolates and the link between epidemics.