Persistence of Psittacine Bornavirus-4 Viral RNA Is Temperature Dependent in Aqueous Environments and Material Dependent in Non-Aqueous Environments

Psittacine bornavirus type-4 (PaBV-4) causes proventricular dilatation disease and death among diverse birds, most notably caged parrots and related species, with no known cure or vaccine. Infected birds can shed virus in fecal matter, urine, and feather dander but it is unknown how well PaBV-4 survives outside of the host. This study focused on assessing the persistence of PaBV-4 in common environmental situations. The presence of viral RNA was examined in aqueous solutions at varying temperatures and recovery from typical avian husbandry materials (plastic, wood, metal, and cloth). Viral RNA persistence in aqueous samples was found to be 3 weeks at 37 °C, 2 months at 24 °C (room temperature), and 3 months at 4 °C. Viral RNA was also recovered from plastic and metal surfaces up to 72 h after inoculation. Also examined were disinfection protocols comparing coverage versus contact time for a reduction in viral RNA. Complete coverage by the disinfecting agent was more important for preventing recovery of viral RNA. Additionally, PaBV-4 RNA was transferable by paper towel. These results provide the first evidence of the robust nature of PaBV-4 in an aqueous environment and show that cleaning protocols need to be carefully curated to limit possible viral spread.