Isolation, identification and pathogenic characteristics of tick-derived parainfluenza virus 5 in northeast China.

The number of parainfluenza virus 5 (PIV5) infection cases has increased worldwide over the past six decades; however, factors underlying this increase remain unclear. PIV5 has been emerging or re-emerging in humans and animal species. To date, no information is yet available regarding PIV5 infection in arthropod ticks. Here, we successfully isolated tick-derived PIV5 from the Ixodes persulcatus species designated as HLJ/Tick/2019 in Heilongjiang, China. Phylogenetic analysis revealed that the tick-derived PIV5 is closely related to subclade 2.2.6, which has become the dominant subtype prevalent in dogs, pigs and wildlife across China. Further experiments to understand the importance of this virus as an infectious vector revealed that a ferret animal model experimentally infected with Tick/HLJ/2019 via the oronasal and ocular inoculation routes developed moderate respiratory distress with pneumonia and neurologic tissue damage from inflammation for the first time. Further surveillance of PIV5 in vectors of viral transmission is necessary to enhance our knowledge of its ecology in reservoirs and facilitate the control of re-emerging diseases.