Queensland’s tropical climate and diverse ecosystems, presents a perfect breeding ground for pesky mosquitoes! It may be even considered a hotspot for mosquito-borne viruses. These tiny insects are not only annoying pests but also vectors (carriers) for various pathogens that can cause diseases in humans.

Prevalence of Mosquito-Borne Viruses

Queensland seasons give rise to the circulation of several mosquito-borne viruses, with the prevalence varying across regions. The most notable among these viruses include:

  1. Ross River Virus (RRV): Ross River virus infection, characterized by fever, rash, and joint pain, is endemic in many parts of Queensland. With its transmission cycle involving various wildlife reservoir hosts, RRV poses a persistent threat to public health in Queensland. In fact Qld Health issued advice of a heightened risk of RRV in February this year.
  2. Dengue Virus (DENV): Dengue fever is a significant public health concern in Queensland, especially in urban and semi-urban areas. According to Queensland Health, there have been recurrent outbreaks of dengue, primarily caused by Aedes aegypti mosquitoes, which thrive in urban environments and breed in artificial containers like water tanks and discarded tires.
  3. Murray Valley Encephalitis Virus (MVEV): While less common, Murray Valley encephalitis virus is a potentially fatal mosquito-borne virus found in northern Australia, including parts of Queensland. It causes severe neurological complications, including meningitis and encephalitis. The virus is transmitted by infected Culex annulirostris mosquitoes.
  4. Barmah Forest Virus (BFV): Barmah Forest virus, like Ross River virus, causes symptoms such as fever, rash, and joint pain. It is prevalent in coastal regions of Queensland and is transmitted by mosquitoes, particularly Aedes vigilax and Culex annulirostris.
  5. Japanese Encephalitis Virus (JEV): Japanese encephalitis is a rare but potentially serious viral infection transmitted by mosquitoes, primarily Culex annulirostris, in northern Queensland. While cases are sporadic, the severity of the disease underscores the importance of surveillance and prevention measures.

 

What can be done to reduce virus transmission?

  • Preventive measures such as using insect repellents, wearing protective clothing, and eliminating mosquito breeding sites (such as pot/containers filled with water).
  • Vaccination: While vaccines are not available for all mosquito-borne viruses, vaccination against diseases like Japanese encephalitis is recommended for individuals at risk, such as travellers to endemic regions.

It’s certainly worthwhile to be mindful that in ‘in 2023, there were 699 cases of Ross River virus infection recorded across the state. Statewide, there has been 64 cases notified in January this year’.  Whilst you can be bitten at any time of day, many mosquitos are most active at dawn and dusk.

We hope this serves as a reminder to apply your insect repellent and wear appropriate clothing so can prevent mosquito bites.

You can always contact your doctor if you have any concerns about these viruses. Our clinics also have travel health services should you be seeking advice about travelling to certain areas where risks are greater.

 

Sources:

  1. Queensland Health. (n.d.). Dengue
  2. Queensland Government. (2023). Mosquito-borne Diseases
  3. Australian Government Department of Health. (2022). Mosquito-Borne Diseases
  4. Ritchie, S. A., & van den Hurk, A. F. (2018). Barmah Forest Virus: Epidemiology and Control. In Advances in Virus Research (Vol. 101, pp. 211–254). Elsevier.
  5. Heightened risk of Ross River virus in Queensland | Queensland Health