Japanese encephalitis

Japanese encephalitis is a virus caused by the Japanese encephalitis virus. It is transmitted to human via the bite of the infected mosquito. It is does not spread from human to human.In many people it is just a mild disease with no symptoms . However in a small percentage of people (1 in 200) it can lead to serious complications of inflammation (encephalitis) and even death. 

Japanese encephalitis will normally present with fever, vomiting, headache and lethargy. In the case of encephalitis, the person will have severe headache, stiff neck , fever,confusion, seizures and even coma. This is a critical stage which can cause permanent brain damage and even death. 

A pregnant woman down with japanese encephalitis can also cause much harm to the unborn fetus. 

Japanese encephalitis is more prevalent in rural farming areas in South east Asia and Far east. It occurs especially during the rainy season when mosquito breed fast i.e. from may to September. 

Japanese encephalitis vaccine can help prevent this disease for travelers who go the affected areas for a long period of time. Prevention via immunization is not 100% foolproof. Mosquito repellents, try to stay indoors with mosquito net, avoid going out during sunset when mosquito activities are mot active are also ways to prevent mosquito bites which is the mode of transmission

Who should get Japanese encephalitis vaccine?

1. Those traveling to the Southeast Asia and Far East epidemic areas for more than one month

2. Travelers traveling to epidemic areas less than one month but will be spending more hours outdoors in the rural areas. 

3. Travelers travelling to areas with an active Japanese encephalitis outbreak. 

4. Laboratory workers who come into contact with the Japanese encephalitis virus. 

Japanese Encephalitis Vaccine 

It can be given to anyone more than 2 months old. Two doses at an interval of 28 days apart of each other. The second dose must be given at least 1 week prior to travel. A booster vaccine should be given within two years from the initial course of two injections. 

The vaccine is a live vaccine which will stimulate your body to produce antibodies against the virus. 

Side effects from JE vaccine

With any medicine there is a chance of side effects which often is very mild which will resolve on its own. 

Minor side effects include pain and swelling at injection site, headache, muscle ache and fever (more common in children). Severe reactions like allergic anaphylactic reaction is very rare (1 in 1 million chance). These severe reaction usually occur within minutes to hours post injection. 

Contraindications to JE vaccine

1. Pregnant women and lactating women as the risk is still unknown. 
 
2. Those who developed an allergy reaction to japanese encephalitis vaccine before and those who have allergic to the components of the JE vaccine. 

3. Acutely ill people with fever should delay the vaccination till they recover.