Evolution of Avian orthoavulavirus 16 in wild avifauna of Central Asia.

In 2014, a novel Avian orthoavulavirus 16 species was described among wild birds in Korea. In 2018, after massive parallel sequencing of archival strains of Avian orthoavulaviruses, isolated in 2006 in Central Kazakhstan, isolates belonging to this serotype were detected. The obtained data allowed to trace the evolution of this serotype in Asia and to reveal its evolutionary relationships with other subfamily species. It was determined that Avian orthoavulavirus 16 is phylogenetically very close to Avian orthoavulavirus 1 (Newcastle disease virus) in its genomic characteristics. It is known that Avian orthoavulavirus 1 is divided into two phylogenetically distant Classes I and II. Avian orthoavulavirus 16 turned out to be very close to lentogenic Class I, which circulates mainly among wild birds. It was suggested that Avian orthoavulaviruses 1 and 16 may have common evolutionary origin and in ecological terms, both serotypes are circulating among wild birds of the order Anseriformes (ducks and geese), but Avian orthoavulavirus 1 has gradually replaced Avian orthoavulavirus 16 from active circulation.