Japanese Encephalitis

It usually takes four to 14 days for symptoms such as fever, muscle aches and severe headaches to develop. In some people, symptoms may progress to include stiffness of the neck and eventually coma, which can result in death or irreparable brain damage.

For travellers, there is a very low risk of being infected, but the consequences of the disease can be high. Japanese encephalitis can result in death and brain damage in a significant proportion of those developing the disease.

The first line of defence against Japanese encephalitis is avoiding mosquito bites by following strict insect prevention measures.

Two vaccines are available, and both are very effective in prevention. One vaccine is a ‘live’ single-dose formula that protects individuals over 18 years of age long-term. Those aged nine months to under 18 will need a second dose 18 months to two years apart if they are at continued risk of infection. The second vaccine involves a course of two injections over a month. A booster is recommended after one to two years if the risk is ongoing. This Japanese encephalitis vaccine is suitable for children as young as two months at a reduced dosage.

Consider vaccination against Japanese encephalitis if you will be:

• spending time in rural or peri-urban areas of risk countries, particularly in the wet season, and if staying in basic accommodation
• repeatedly visiting or moving as an expatriate to outbreak areas or endemic countries
• travelling to a region where an epidemic is underway.

At present, vaccination in Australia is only available to those deemed at high risk by the government. This may change with time.

More recently, there have been increasing numbers of infections among tourists. It appears that the disease risk may be moving into peri-urban areas as well, due to population movement and climate change. This year it has occurred in Australia, likely due to uncharacteristic amounts of rain and weather patterns.

There is currently no specific treatment available for Japanese encephalitis, just symptomatic treatment; however, it is a good idea to seek medical care if you feel you may have symptoms consistent with the disease.