The role of bats as reservoir hosts for multiple zoonotic pathogens makes the surveillance of bats and the discovery of novel viruses necessary to prepare for emerging infectious diseases. Characterisation of novel bat-borne viruses improves our understanding of their zoonotic potential and prevents virus spillover from having a significant public health and economic impact. Previous surveillance of Australian fruit bats has resulted in the identification of multiple viruses from the Paramyxoviridae family, so pteropid bat urine was collected in Alstonville, New South Wales to be assessed for the presence of novel viruses.
A novel virus, Alston paramyxovirus (AlsPV), was isolated from these bat urine samples and then further analysed by whole genome sequencing, cross-reactivity and neutralisation assays, growth kinetics assays and experimental infection of ferrets and mice to better understand its potential to cause disease. Whole genome sequencing showed that AlsPV belongs to the genus Rubulavirus and is most closely related to Parainfluenza virus 5, the causative agent of respiratory disease in dogs. Despite the high sequence similarity, there are only low levels of antigenic cross-reactivity between these two viruses. Experimental infection of ferrets and mice resulted in the shedding of infectious virus in respiratory secretions of ferrets between days 3-7 in the absence of clinical disease, with a rise in neutralizing antibodies detected after day 10. Interestingly, there was also evidence of viral RNA in the brains of two mice at euthanasia.
The isolation of AlsPV provides a greater understanding of the viral diversity present in Australian bats. These results indicate that AlsPV replicates in ferrets at sites relevant to virus transmission, in addition to potentially infecting the central nervous system. Further research will be conducted to characterise the tissue tropism and pathogenesis of AlsPV during acute infection, and to understand more about the potential transmission of this virus.