What is it: Japanese encephalitis (JE) is a disease that is spread
to humans by infected mosquitoes in Asia. It is one of a group of
mosquito-borne virus diseases that can affect the central nervous system and
cause severe complications and even death. It is a seasonal disease that
usually occurs in the summer and fall in temperate regions of China, Japan,
and Korea. In other places, disease patterns vary with rainy seasons and
irrigation practices.
How do I get it: JE virus is transmitted chiefly by mosquitoes that
live in rural rice-growing and pig-farming regions.
What happens if I get it: symptoms usually appear 6-8 days after the bite of an
infected mosquito. Most infected persons develop mild symptoms or no symptoms
at all. In people who develop a more severe disease, Japanese encephalitis
usually starts as a flu-like illness, with fever, chills, tiredness,
headache, nausea, and vomiting. Confusion and agitation can also occur in
the early stage. The illness can progress to a serious infection of the brain
(encephalitis) and can be fatal in 30% of cases. Among the survivors,
another 30% will have serous brain damage, including paralysis.
Diagnose and treatment: diagnosis is based on tests
of blood or spinal fluid. There is no specific treatment for Japanese
encephalitis. A vaccine is licensed for use in travellers whose itineraries
might put them at risk for Japanese encephalitis. All travellers should take
the usual precautions to avoid mosquito bites to prevent Japanese
encephalitis and other mosquito-borne diseases.
How can I
avoid contractingJapanese
encephalitis: avoid being bitten by mosquitoes. The mosquitoes that
transmit Japanese encephalitis feed mainly outside during the cooler hours at
dusk and dawn. Travellers should minimize outdoor activities at these times,
use mosquito repellent on exposed skin, and stay in air-conditioned or
well-screened rooms. Travellers to rural areas should use a bed net and
aerosol room insecticides.
