Press the Back button to return to the list of fact sheets.

JAPANESE ENCEPHALITIS (JE)

JE is a virus that can result in serious brain infection in humans. The virus can live in animals such as pigs and wading birds without affecting them. If humans are infected, via the bite of certain mosquitoes, they do not always become ill, but if they do, death or permanent disability may result. The culprit mosquitoes are usually found in areas of ground water, typically, irrigated rice paddies. The disease occurs in the whole of East, Southeast and South Asia, with risk usually greatest during the monsoon months. In recent years it has appeared in the southwest of PNG and the Torres Strait. About 100,000 cases are reported annually, but the disease is probably under-reported in poorer countries.

It usually takes from 4 to 14 days from infection to the onset of symptoms such as fever, muscle aches and severe headache. In some individuals, this progresses to neck stiffness and coma that can result in death or permanent brain damage. There is no specific treatment available.

PREVENTION

Once again, the first line of defence is mosquito avoidance.

A very effective vaccine is available and has been used extensively in Asia for many years. Vaccination involves a course of three injections (day 0, 7 & 30) and a booster 3-yearly if needed for on-going risk.

The vaccine is usually recommended for adults and children over 12 months of age who:

• Will be spending a month or more in rice-growing areas of countries at risk
• Repeatedly visit such areas
• Are travelling to areas where an epidemic is known to be occurring

The last dose of the vaccine should preferably be completed at least 10 days before the trip, to monitor for any delayed allergic reactions.

Back to Contents