Kunjin Virus: Insights into Emergence and Transmission Dynamics

The severe neurotropic Kunjin virus (KUNV) is an attenuated strain of West Nile Virus (WNV) and has been modified. The reader is advised to read an in-depth review by Marshall for a comprehensive description of the history, ecology, and epidemiology of KUN viruses (1988). Although, the KUN virus, which bears the name of one of the local aboriginal tribes, was initially discovered in 1960 in Culex annulirostris mosquitoes trapped at Mission River in North Queensland, Australia. A polyprotein is encoded by the virus’s single-strand positive-sense RNA genome. After gene expression, the polyprotein is split into non-structural proteins for viral replication and expression and structural proteins for viral packing. With particularly aggressive strains recently producing illness outbreaks in Eastern Europe, the Middle East, and North America, West Nile Virus (WNV) is a mosquito-borne virus that causes outbreaks of viral encephalitis in humans and horses. Infection with the WNV Kunjin (WNVKUN) strains is typically asymptomatic and endemic in northern Australia. On a template of recycled double-stranded RNA (dsRNA) or replicative form, asymmetric and semiconservative replication produce offspring RNA (+) strands (RF). The cycle time for the displacement of the pre-existing RNA (+) strand in the replicative intermediate, according to the viral RNA production kinetics, is about 15 min. This view outlines what we currently know about WNVKUN and how its ecology and epidemiology have changed.