January 21, 2025Summer brings sunshine, outdoor fun, and unfortunately, the unwelcome buzz of mosquitoes. A recent outbreak of Japanese encephalitis in mosquitoes has raised alarms across northern Victoria, with health authorities urging vigilance among residents and visitors.
The discovery of two infected mosquitoes in Moira Shire, near Cobram and Yarrawonga, highlights the presence of this rare but potentially serious virus in inland riverine regions, particularly near the Murray River.
What is Japanese encephalitis?
Japanese encephalitis is a viral infection that can cause inflammation of the brain. Symptoms range from fever and headaches to seizures, paralysis, and, in severe cases, coma. The virus is spread through the bites of infected mosquitoes, posing a heightened risk during warmer months when mosquito activity peaks.
In a recent article in the Herald Sun, Victoria’s Chief Health Officer, Dr Tarun Weeramanthri, emphasised the importance of prevention, “The best defence is to limit outdoor exposure and use insect repellents in high-risk areas.” While no specific treatment exists for the virus, a free vaccine is available for eligible individuals in 24 high-risk zones.
Tackling mosquito-borne diseases with innovation
Mosquito-borne diseases like dengue fever cause hundreds of thousands of deaths annually. To combat this, Oxitec Australia, a collaboration between the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and UK-based Oxitec Ltd, is introducing genetically modified mosquitoes (GMMs) in Australia.
These GMMs are non-biting male mosquitoes designed to produce only healthy non-biting male offspring. By reducing the number of female mosquitoes, this innovative approach aims to control the spread of diseases like dengue, zika, and chikungunya.
Professor Brett Sutton, Director of Health and Biosecurity at CSIRO, in an interview for ABC’s RN Radio said, “Mosquito-borne diseases have spread significantly in recent years due to climate change. By investing in new and innovative solutions that complement existing control programs, we can reduce the public health impacts of these exotic and invasive mosquito species.”
Expert advice on mosquito bites
We spoke with Dr Daniel Engelman, Paediatrician and Research Fellow in Tropical Diseases at Northern Health, for advice on mosquito bites.
“Most mosquito bites, despite being very itchy, don’t need medical treatment. Occasionally, adults or children may develop a large local reaction with swelling or ongoing pain. In some cases, bites can become infected, showing signs like increasing redness, swelling, warmth, or crusting,” he explains.
Signs of severe illness:
- Fever
- Vomiting
- Progressive rash
- Joint pains
“If you notice any of these signs, seek medical attention from your local GP, Urgent Care Centre, or the Victorian Virtual Emergency Department,” advises Dr Engelman.
Tips for a bite-free summer
Prevent mosquito bites and enjoy summer with these simple strategies:
- Apply repellent regularly and evenly to all exposed skin (on top of sunscreen)
- Wear long, loose-fitting, light-coloured clothing and enclosed shoes
- Empty or remove buckets and containers around your home to reduce mosquito breeding
For itchy bites:
- Apply a cool pack or have a cool bath
- Use lotions or topical sprays to relieve the itch
- Consider oral antihistamines if the itch is severe and impacting sleep
- Use distraction techniques for children and keep fingernails short to prevent scratching
The best way to avoid mosquito-borne illnesses is to prevent bites altogether. For more tips and resources on mosquito protection, visit Victoria Health’s Mosquito Protection Guide.
