Ross River virus (RRV) is an endemic, mosquito-borne pathogen that occurs all over Australia.
The virus was first isolated from Aedes vigilax mosquitoes collected on the banks of the Ross River in Townsville in 1959 but it was not associated with clinical symptoms until some years later.
Approximately 5,000 cases are notified every year with sporadic outbreaks also recorded in the Pacific Islands. The largest Australian epidemic (9,550 cases) occurred in 2015, with the majority of cases recorded in Queensland.
Acute symptoms usually develop within 7 to 9 days of contracting the virus and include fever, rash, joint and muscle pain, swollen lymph glands, sore throat and fatigue. Debilitating chronic joint pain may last for several month or even years.
The transmission of RRV is complex and multiple mosquito species may be responsible. Across Australia, more than 40 mosquito species have been associated with the virus in the field. These include the common pest species Culex annulirostris, Aedes vigilax, Aedes procax, and Aedes notoscriptus.
RRV infects mosquitoes when they bite viraemic vertebrates that include horses, kangaroos, possums, birds and other native wildlife. We have a poor understanding of the key virus reservoirs and transmission pathways in different habitats.
Those who are more likely to get RRV infection are:
- people who live or work in warm, humid climates near bodies of water
- people who have visited or live in or around wetlands or rivers, particularly during the summer months
- people who work or do outside activities (for example, camping, fishing, hiking, gardening) in coastal and inland areas
There is currently no vaccine against RRV. The best way to avoid the virus is to not get bitten by mosquitoes. Protect yourself:
- Use insect repellent. The best mosquito repellents are those the include either diethyltoluamide (DEET), picaridin, or oil of lemon eucalyptus
- Wear long, loose fitting and light-coloured clothing and covered shoes when outside
- Avoid spending lots of time outdoors at dawn and dusk when mosquitoes are most active
- Cover windows, doors, and other entranced with insect screens
- Remove any containers around your home that hold water where mosquitoes may breed
