Molecular characterization of rabies virus in trade dogs from Plateau state, Nigeria

Rabies is one of the most dreaded diseases known to mankind and it is endemic in Nigeria. This study was aimed at the detection and molecular  characterisation of the rabies virus antigen in trade dogs in Plateau State. A cross-sectional study was performed to determine the prevalence of rabies  antigen in the brain tissues of slaughtered dogs, from February to June 2018 using a direct fluorescent antibody test and mouse inoculation technique.  Direct Fluorescent Antibody Test, Polymerase Chain Reaction (PCR), sequencing and phylogenetic analysis of the identified rabies virus were also  undertaken. Phylogenetic analysis was done using molecular evolutionary genetic analysis (MEGA) 10 to determine their evolutionary relationship with  other rabies virus sequences deposited in Genbank. Results indicated, out of 450 dog brain samples tested 14(3.1%) were positive for rabies virus  antigen. Zoographic data obtained showed 66.3% of dogs were female, and the dogs were kept mainly for security (n=54) and breeding (n=28). Fourteen  positive samples were used to inoculate 70 adult mice, only 8 samples were positive and 2 samples were also positive by RT PCR. Phylogenetic analysis of  the nucleotide sequences showed that the two rabies virus sequences in this study, sequence MZ148311 had very close identity with EU038106 (99.8%  homology) and sequence MZ148312 had perfect identity with EU038087 (100% homology) was most closely related to lyssavirus that has been reported  to be circulating previously in Plateau and Nigeria, belonging to the Africa 2 lineage.