The risk of mosquito borne infection is increased during the current Australian summer season. Various mosquito borne diseases occur in Australia such as:

• Ross River fever (RRF) is the most commonly reported mosquito-borne disease in Australia, averaging around 5’000 infections each year, although this is likely to be an underestimate of the true number. It is widespread in Australia but more commonly found in Queensland, the Northern Territory and the Kimberley region of Western Australia. Ross-River-virus is an arthritogenic alphavirus.
  
• Murray Valley encephalitis (MVE) - MVE virus is enzootic (endemic in animals) in freshwater habitats of the Kimberley region of Western Australia and the northern area of the Northern Territory. Occasional outbreaks occur as far south as NSW following the migration of infected birds and with local mosquito populations boosted by rainfall/flooding. While most people with MVE virus are asymptomatic, apparent clinical infection is often severe due to neurological involvement, causing death in approximately 15-30% of cases and residual mental or functional disability in up to half of those who survive. The causative virus belongs to the family of flaviviruses.
  
• Dengue - the dengue virus is no longer endemic in Australia but is introduced each year by infected travellers arriving from overseas. Risk of infection is elevated in Queensland or on the Cocoseilande (Throat Islands). 
  
• Japanese Encephalitis occurs in Australia. First outbreaks were reported in 2022 in the states of Queenland, New South Wales (NSW) and Victoria - mainly in the Murray valley with over 70 pig farms affected throughout temperate regions of the country. Human cases and deaths had been reported. In the current season 2024/25, only sporadic human cases have been reported so far. The situation in Torres Strait and Cape York Pennisula in north eastern Australia is unclear since surveillance has been stopped since many years.

For more details to the diseases and other mosquito borne disease in Australia such as Barma Forest and Kunjin virus (a subtype of West Nile virus) infection, see LINK.