The following background information on Kunjin virus infection is abstracted from Gideon www.GideonOnline.com and the Gideon e-book series  Primary references are available on request.
Kunjin virus (KUN), a subtype of West Nile virus, was first isolated in Australia in 1960, from mosquitoes (Culex annulirostris). The virus is named for an Aboriginal clan living on the Mitchell River in Kowanyama, northern Queensland
Most cases of human infection are reported in Australia, with sporadic reports from Nepal. Serosurveys suggest the presence of human infection in Malaysia, Indonesia and Papua New Guinea.
In Australia, Kunjin virus infection is more widely distributed than another flavivirus disease, Murray Valley Encephalitis. The yearly incidence varies from 0-to-9 cases per year (see Graph). KUN is reported in most of tropical Australia, eastern Queensland, and occasionally southeastern Australia. The disease appears to have been responsible for some reports of “Murray Valley encephalitis” in 1974, and was implicated in an additional sporadic case in northern Victoria in 1984. A presumptive case of KUN was reported in Pilbara, Western Australia in 1997. In 2000, the disease reappeared in Central Australia, where it had last been documented in 1974. Thirteen cases were reported in Northern Territory during 1992 to 2010, and an outbreak of Kunjin virus encephalitis was reported among horses in New South Wales in 2011.
In 2011, 3.1% of blood donors in Mildura, Victoria were found to be seropositive toward KUN. The following year, seropositivity was documented in 0.6% to 0.7% of humans and 12.7% of animals in eastern New South Wales.
The principal mosquito vectors for Kunjin virus are Culex annulirostris, Cu. pseudovishnui and Cu. squamosis. Aedes albopictus has been identified as a potential vector for Kunjin virus in Australia. The virus has also been identified in mosquitoes from Malaysia. Reservoirs include marine birds, pigs and horses.
Kunjin virus infection is often asymptomatic. Overt infection is clinically similar to Ross River disease – arthralgia, fever and rash.
Berger S. Infectious Diseases of Australia, 2019. 551 pages , 165 graphs , 3,407 references. Gideon e-books, https://www.gideononline.com/ebooks/country/infectious-diseases-of-australia/
43 cases were reported during 2001 to 2018, New South Wales 3, Northern Territory 5, Queensland 21, Victoria 6 and Western Australia 8.
- 1996 – Two cases in Queensland.
- 1997 – Two cases in Western Australia and two in Northern Territory.
- 2000 – Three in Western Australia and one in Northern Territory).
- 2001 – New South Wales, Northern Territory [2 cases] and Western Australia.
- 2003 – All cases reported from Queensland
- 2004 – 5 in Queensland and 1 in Victoria.
- 2005 – 1 in Queensland
- 2006 – 2 in Western Australia and 1 in Queensland
- 2017 – 1 in Victoria and 5 in Western Australia