Japanese Encephalitis (JE) is the latest disaster to hit Australia’s shores and newspapers. At the tail end of an ongoing pandemic in the midst of devastating floods in Queensland and NSW, the mosquito-borne disease has found a spot in the limelight.

It’s not the first time the disease has made it to Australia community, but it represents the early stages of a looming threat: the increase in mosquito-borne diseases due to climate change.

Here are four things you need to know about the disease, as well as some advice on how to avoid catching it!


Japanese Encephalitis is a mosquito-borne disease. You can’t catch it without a mozzie bite!

Before we start, you can breathe a sigh of relief: unless the mozzies normally go for that cheeky smile of yours, you won’t be needing a P2 mask or hand sanitiser to keep this disease at bay.

The only way to catch the Japanese Encephalitis virus is through a mozzie bite.¹ Typically, it’ll come from a mozzie in the Culex genus. Although this mozzie is found all over the world, Japanese Encephalitis has predominantly affected Asian nations. To this day, the disease is most commonly found in South Asia and the Western Pacific. ¹

Japanese Encephalitis is counted as one of the 13 Neglected Tropical Diseases – conditions that continue to cause a significant burden of illness in predominantly lower-income countries. ² Other diseases in the list include: dengue fever, rabies, and African Sleeping Sickness.

Japanese Encephalitis is a rare disease, but it can be fatal. Symptoms in the early stages of the disease can include: fever, headaches, confusion, and vomiting. As the infection progresses, symptoms can extend to neck stiffness, disorientation, and seizures.³

Japanese Encephalitis mosquito sitting on a leaf

Symptoms typically occur 5-15 days following transmission of the virus, so keep an eye out for these symptoms if you’ve been to areas of high exposure. Camping, fishing, and hiking are examples of activities that can be higher risk if there are nearby waterways and marshlands.³

The symptoms are the result of encephalitis, or inflammation of the brain. There is no definitive cure, so treatment typically includes supportive therapies and close monitoring in hospital.³

Of the 68,000 people who suffer from serious infection each year, roughly one quarter will have a fatal outcome.⁴


Japanese Encephalitis is like a dot-to-dot: it links a few species together.

Whilst mozzie bites are the only way to catch the disease, it’s not a virus that only affects humans, and mosquitos will typically pick up the virus from another animal before spreading it to people. The current outbreak in Queensland is linked to pig farms. ⁵ Since pigs can be infected without developing symptoms, they’re an ideal reservoir for the virus.

The natural hosts for the virus are birds, which raises some concern that the disease will never truly be eradicated.


Japanese Encephalitis can be prevented – here’s how you can avoid it.

There may be no specific cure for the disease, but simple measures can be used to prevent illness!

Historically, Japanese Encephalitis vaccines have led to widespread control of the disease in previously high-risk countries, including Japan. They’re expensive, though, so they’re not commonly found in routine immunisation programs in lower income countries. ⁶

If you’re not vaccinated, you can still keep yourself safe by following some simple tips: ³

  1. Wear insecticide-treated clothing (such as a Mozzie-Free Tee!)

  2. Apply extra repellent to exposed areas of skin, and remember to re-apply! (PS - always apply repellent after applying sunscreen)

  3. Avoid peak hour mozzie traffic! They are most active at dawn and dusk!

  4. In areas of high density mosquito populations, wear long sleeves and long pants.

  5. Where possible, use fly and insect screens when camping or otherwise nearby mosquito habitats.


This outbreak of Japanese Encephalitis is a reminder of the importance of climate change.

This outbreak hasn’t been shown to be tied to climate change. Whilst we’re still grappling with that question and so many others, it is increasingly accepted that climate change will lead to, “...an expansion of regions with climate suitable for mosquito-borne diseases…”. ⁷
In fact, the World Health Organisation has found that, “...climate change could cause an additional 60,000 deaths by malaria from 2030-50, even if there is ongoing economic development and improvement in public health systems.” ⁷

All of that to say: another way of tackling mosquito-borne disease is to advocate for better climate policy!



  1. Japanese encephalitis [Internet]. Who.int. 2022 [cited 16 March 2022]. Available from: https://www.who.int/en/news-room/fact-sheets/detail/japanese-encephalitis

  2. Hotez P, Aksoy S, Brindley P, Kamhawi S. What constitutes a neglected tropical disease?. PLOS Neglected Tropical Diseases. 2020;14(1):e0008001.

  3. Japanese encephalitis fact sheet - Fact sheets [Internet]. Health.nsw.gov.au. 2022 [cited 16 March 2022]. Available from: https://www.health.nsw.gov.au/Infectious/factsheets/Pages/japanese_encephalitis.aspx

  4. Japanese encephalitis [Internet]. Who.int. 2022 [cited 16 March 2022]. Available from: https://www.who.int/en/news-room/fact-sheets/detail/japanese-encephalitis

  5. [Internet]. 2022 [cited 16 March 2022]. Available from: https://www.outbreak.gov.au/current-responses-to-outbreaks/japanese-encephalitis

  6. Control of Japanese Encephalitis — Within Our Grasp? | NEJM [Internet]. New England Journal of Medicine. 2022 [cited 16 March 2022]. Available from: https://www.nejm.org/doi/full/10.1056/NEJMp058263

  7.  What climate change means for mosquito-borne diseases [Internet]. Lowyinstitute.org. 2022 [cited 16 March 2022]. Available from: https://www.lowyinstitute.org/the-interpreter/what-climate-change-means-mosquito-borne-diseases#:~:text=By%20way%20of%20contrast%2C%20a,improvement%20in%20public%20health%20systems.

July 11, 2022 — Bal Dhital