Epidemiological and molecular analysis of a rabies outbreak in the state of bahia, Brazil

Abstract

This study aimed to genetically characterize rabies virus strains detected in biological samples from 55 laboratory-confirmed rabies-positive animals in the state of Bahia during an outbreak that occurred between 2007–2009. Samples from one donkey, one lesser spear-nosed bat (Phyllostomus elongatus), two crab-eating foxes (Cerdocyon thous), eight common vampire bats (Desmodus rotundus) and 43 bovines were submitted to rabies diagnosis. All samples were positive in the direct immunofluorescence test (DAFT), mice inoculation test (MIT) and reverse transcriptase polymerase chain reaction by (RT-PCR), followed by nucleotide sequencing and phylogenic analysis. The phylogeny presented two viral clades, one bat-specific and one carnivore-specific, with existence of nine sub-clusters associated to Desmodus rotundus and infection of bovines with the carnivore-specific strain. Phylogenetic analysis exposes a complex epidemiology that needs further elucidation for the improvement of control measures for rabies.