Is Ross River virus spread between people?

No. Ross River virus and Australia's other main mosquito-borne diseases are spread by the bite of an infected mosquito and are not passed directly between people through everyday contact such as shaking hands or coughing. That is why preventing bites and managing breeding sites around your home are so important.

Is the Japanese encephalitis vaccine free?

Some states have run free vaccine programs for people such as those living or working in high-risk areas, but the target groups, eligibility, and timeframes differ by state and season and change frequently. To find out whether you are eligible, check the latest guidance from your state's health department and health.gov.au, and talk to a GP. This guide does not make a determination about your eligibility.

Does Australia have dengue?

Most dengue cases reported in Australia are acquired overseas while travelling. Local transmission within Australia is limited to parts of far north Queensland, where the urban mosquito (Aedes aegypti) is found. Take care to prevent bites before and after travelling to tropical regions, and if you have symptoms such as a high fever after returning, tell your GP about your travel history.

Which repellent should I use?

Australia's official guidance points to products containing an effective active ingredient (for example, DEET or picaridin) rather than a specific brand, applied to exposed skin as directed. For children and pregnant women, the product label and healthdirect or state health department guidance take precedence. Check the specific ingredients and age-based instructions from official sources.

When are mosquitoes most active?

Mosquitoes are generally more active in spring and summer (roughly September to February) and during wet periods, and within a day they tend to be especially active at dawn and dusk. That said, it varies by mosquito species and region, so don't let your guard down during the day either, and it's a good idea to follow local alerts.

What should I do if I have symptoms after being bitten?

If you have symptoms such as fever, joint pain, muscle pain, or a rash, consult a GP or healthdirect (1800 022 222). It helps to mention any recent outdoor activity or travel history. Testing and treatment for a diagnosis are up to your healthcare provider, and this guide does not replace diagnosis or prescription.

Does flooding increase the risk of mosquito-borne disease?

Yes. When rainfall and flooding increase, there is more standing water, which makes mosquito breeding more active and can raise the risk of infection. In 2022, for example, Japanese encephalitis spread into the inland south-east after major flooding. After rain, empty standing water around your home often and check local alerts.

Preventing mosquito-borne disease in Australia — Ross River, Japanese encephalitis, dengue - Victoria

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Preventing mosquito-borne disease — Ross River, Japanese encephalitis, dengue

A summary, based on official Australian sources, of prevention tips for the mosquito-borne diseases that increase in Australia over spring and summer (Ross River, Japanese encephalitis, dengue) and how to check your vaccine eligibility.

Overview: mosquito-borne diseases in Australia

In Australia, mosquito activity rises from spring through summer (roughly September to February), increasing the risk of mosquito-borne disease. The most common is Ross River virus, and since 2022 Japanese encephalitis (JE) has been newly identified in the inland south-east. Dengue is mostly acquired overseas and brought back, and local transmission within Australia is limited to specific regions. Because many of these diseases have no vaccine or specific cure, not getting bitten is the surest form of prevention. This guide is general public health information for people living inland or in the north, those who spend a lot of time outdoors, and anyone preparing to travel to a high-risk area. For seasonal health risks such as spring pollen and thunderstorm asthma, or outdoor bites and stings from snakes and spiders, please see the dedicated guides for each.

Ross River, Japanese encephalitis, and dengue at a glance

Ross River virus occurs across Australia and is characterised by joint pain, fatigue, and a rash, but it is usually not life-threatening. Japanese encephalitis is rare but can lead to severe encephalitis, and a vaccine is available — because pigs and waterbirds are amplifying hosts for the virus, the risk is greater near farming facilities and wetlands. Dengue has local transmission reported only in parts of far north Queensland, where the urban mosquito (Aedes aegypti) is present, while cases elsewhere are mostly acquired while travelling. Decisions about symptoms, testing, and treatment are up to your GP, and this breakdown is general information to aid understanding.

The four principles of mosquito protection — key prevention tips

Because many of these diseases have no vaccine or cure, avoiding mosquito bites is the core of prevention. The mosquito-protection advice that Australian health authorities (healthdirect and state health departments) commonly give falls into four broad areas: reducing skin exposure, using repellent, blocking mosquitoes from getting indoors, and removing breeding sites. The tips below are general public health information rather than a specific brand, so follow official channel guidance for product ingredients and how to use them.

Using repellent correctly

Australia's official guidance advises applying repellent containing an effective active ingredient (for example, DEET or picaridin) evenly to exposed skin and reapplying at the intervals shown. It does not specify a particular brand, and for children and pregnant women it is safest to check the product label and healthdirect or state health department guidance. Always confirm detailed ingredients and age-based use from official sources.

Reduce skin exposure with light-coloured, loose-fitting clothing such as long sleeves and long pants.

Japanese encephalitis vaccine — checking eligibility

Unlike Ross River and dengue, Japanese encephalitis (JE) has a vaccine. After human infections were confirmed in the inland south-east in 2022, some states have run free vaccine programs for people such as those living or working in high-risk areas. However, the target groups, eligibility, and timeframes differ by state and season and change frequently — this guide does not make a determination about eligibility, and you must confirm whether you qualify with your state health department and health.gov.au and consult a GP. For records of vaccines you have already received, see the separate guide on checking your immunisation record (AIR).

Check whether your area of residence or work is a JE high-risk area (for example, near rivers, wetlands, or pig farming facilities).
Check the eligibility conditions for the free vaccine and how to apply on your state health department's official page.

Four main diseases

Here is a summary of the mosquito-borne diseases most often mentioned in Australia, organised by their features. Because outbreak areas and timing vary by season and year, check the latest alerts on healthdirect and your state health department. The following is general information to aid understanding, not a diagnosis.

Ross River virus

The most common mosquito-borne disease in Australia. It can cause joint pain, muscle pain, fatigue, a rash, and a mild fever, and symptoms sometimes last for weeks to months. There is no vaccine or specific medicine, so preventing bites is key, and symptom management is discussed with a GP.

Japanese encephalitis

Most infections cause no or mild symptoms, but rarely they can progress to severe encephalitis. Pigs and waterbirds are amplifying hosts, and a vaccine is available. Who qualifies for the free vaccine differs by state and season, so check with your state health department and health.gov.au.

Dengue

Characterised by high fever, severe headache, and joint pain. Local transmission within Australia is limited to parts of far north Queensland, where the urban mosquito (Aedes aegypti) is present, and other cases are mostly acquired while travelling overseas. Take care with mosquito protection before and after travelling to tropical regions.

Murray Valley encephalitis, Barmah Forest, and others (MVE, Barmah Forest)

Preparation tips by season and region

Mosquito risk rises in spring and summer and during wet periods. When rainfall and flooding increase due to La Niña and similar patterns, there is more standing water and mosquito breeding becomes more active; in 2022, Japanese encephalitis spread into the south-east after major flooding. The following are preparation tips by season and region; for disaster response to floods, bushfires, and the like, please see the separate natural disaster guide.

Before spring arrives (late winter to early spring), check insect screens and mosquito nets and get your mosquito-protection supplies ready in advance.
After rain and flooding, empty standing water around your home often and check local mosquito alerts.

Common misconceptions and mistakes

Here is a summary of things that are easy to get wrong. The following is general information; always confirm symptoms, testing, treatment, and vaccine eligibility with healthcare providers and official sources.

'It spreads between people' — Ross River, JE, and dengue are, as a rule, spread through mosquitoes and are not passed directly between people through everyday contact.
'It's winter, so I'm fine' — the risk is mainly in spring and summer, but in the warm north or after rain you should watch out for bites regardless of the season.

Life in Australia Guide