Evidence for a host switching in the maintenance of canid rabies variant in two wild carnivore species in the Northern Cape Province, South Africa

Abstract

Rabies is a zoonotic infectious disease that causes at least 59 000 human deaths worldwide annually, with 95% of the cases occurring in the developing countries of Asia and Africa. There are two Lyssavirus rabies (RABV) variants circulating in South Africa, notably the canid and mongoose RABV biotypes. The canid RABV biotype is maintained in the domestic dog and two wild carnivore species, the black-backed jackal (Canis mesomelas) and the bat-eared fox (Otocyon megalotis). The yellow mongoose, a member of the Herpestidae family, is a reservoir and vector species for the mongoose RABV biotype. Rabies trends showed an increase in rabiespositive cases in aardwolves between 2011 and 2016 surpassing the bat-eared fox as the most rabies-affected wild carnivore in the Northern Cape Province of South Africa. The aim of the study was to establish the genetic relationships amongst rabies viruses recovered from both the aardwolves and bat-eared foxes. A partial region of the glycoprotein gene and the variable G-L intergenic region of the viral genome were analysed using nucleotide sequences generated from PCR amplicons. The rabies viruses recovered from the aardwolves between the year 2015 and 2017 were 100% nucleotide sequence identical, suggesting a single or common source and possible evidence for a host shift. Furthermore, the phylogenetic reconstruction demonstrated that the rabies viruses obtained from the two wild carnivore species from the Northern Cape Province clustered independently of each other with 96% nucleotide sequence identity, suggesting that the aardwolf may be able to maintain the canid RABV variant in this geographical area.