Study of Lyssaviruses of Bat Origin As a Source of Rabies for Other Animal Species in the State of Rio De Janeiro, Brazil

An epidemic-geographic rabies study was carried out in which 72 animal and human brain samples were analyzed for Lyssaviruses by a direct immunofluorescent technique (DIFT) and a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Fifty-two samples were also tested by a mouse inoculation test. Lyssavirus RNA was detected in 60 of 72 samples. Five DIFT-negative bat samples tested by a nested PCR assay showed evidence of the presence of rabies virus RNA. Sequencing of amplified rabies virus nucleoprotein encoding segments of a selection of the samples resulted in the formation of clusters, corresponding to samples originating from cattle and equines from the same hydrographic basin. Genomically related Lyssavirus strains of bat origin were found in each cluster, most likely because of the role of the bat in the epidemiology of the virus. All samples studied were of genotype 1. With exception of the human sample, all were distinct from the reference sample.