Australia's Japanese Encephalitis Outbreak Spreads Down South

As Australia heads into its summer season, a Japanese encephalitis (JE) outbreak is expanding in rural areas surrounding the Murray River.

In November 2022, the JE virus was detected in pigs in the Murray River region, confirming the risk for JE in humans in this area.

The Murray River is located in Southeastern Australia and is the third longest navigable river in the world, after the Amazon and Nile.

Australia's JE outbreak began in 2021.

Then, on March 6, 2022, the government declared the JE outbreak in Queensland a Communicable Disease Incident of National Significance.

A mathematical model published in Clinical Infectious Diseases in October 2021, led by the QIMR Berghofer Medical Research Institute in Brisbane, suggested that up to 750,000 people across Australia could be at risk of exposure to the JE virus (JEV).

To notify travelers, the U.S. Centers for Disease Control and Prevention (CDC) published an updated Level 2 travel advisory on December 14, 2022.

However, most travelers to Australia are at very low risk for JE, says the CDC.

But, JE vaccination is recommended for longer-term (one month) travel to areas surrounding the Murray River and Outer Torres Strait Islands.

However, for most travelers, the chance of getting infected with JEV is low, says the CDC.

There are two ways to protect yourself from JEV infection:

Avoiding being bitten by mosquitos is one way.

The JEV is spread to people through the bite of an infected mosquito.

Most people who get infected experience mild or no symptoms. In people who develop severe disease, early symptoms include fever, headache, and vomiting. Seizures are more common in children, says the CDC.

The second prevention tactic is to be vaccinated.

There are two JEV vaccines available globally.

For example, Valneva SE's Ixiaro is an inactivated, adsorbed Vero cell culture-derived vaccine approved by the U.S. FDA.

Ixiaro is available in the U.S. at certified travel clinics and pharmacies.

The CDC suggests other travel vaccinations when planning a visit to Australia.

Vax-Before-Travel publishes fact-checked, research-based travel information manually curated for mobile readers.