Japanese encephalitis

Japanese encephalitis virus is an infection mediated mainly by Culex tritaeniorhynchus, which causes severe acute encephalitis in humans. Even when infected, the disease develops to about 100 to 1000 people at an instance, the majority of which is asymptomatic. However, the mortality rate when encephalitis develops is about 15%, there are about 50% of those who leave the sequela of nerves, and the only 1/3 of all patients are completely cured.

The epidemic period of Japanese encephalitis

Cases regarding the virus has drastically decreased compared to the first half of the year, but in Asia, especially in the monsoon Asia region, it is still a persistent disease and there are frequent epidemics. It is estimated that there are around 50,000 patients that are affected by this virus world wide.

In temperate regions like Japan, Korea and China, the epidemic period is limited to 2 to 4 months mainly in the summer. These months are considered the rainy season in the tropical region. Unlike other areas, Thailands rainy season is very long, spanning from May to October in the northern part of the country, but the number of patients is decreasing due to the spread of vaccination in recent years.Previously it was seen sporadically in rural areas near Bangkok, but recently there have be no reported sickness of such virus. At this point itseems that the virus has been eradicated from Bangkok


The incubation period is between 6 and 16 days. In a typical case, it develops with high fever (38 to 40 ° C. or more) for several days, headache, nausea, vomiting, etc., stiff rigidity as meningeal irritation symptom appears, and convulsions, abnormalities Exercise is often seen.Japanese encephalitis is a disease in which prevention is important because once infected treamtmen is difficult. By the time symptoms arise, the virus has already reached the brain leading the death of braincells Braincells are not regenerative and it is almost impossible to restore.

Pathogens of Japanese encephalitis

Japanese encephalitis a virus belonging to Flaviviridae flavivirus genus. In temperate zones such as Japan, it is mediated by Culex tritaeniorhynchus, which occurs in paddy fields. In the tropics, several other mosquitoes are said to be the base of mediation.In nature, the infection of f Japanese encephalitis virus is formed by mosquito and pig (or avian). There is no human to human infection, but mosquitos carrying the virus from absorbing an infected persons blood can transfer the disease to other people.

Vaccine for JE

Vaccine prevents from getting JE.

■Frequently used vaccine in Thailand

・Number of shots: Once

・Duration: 5 years

・Frequently used vaccine: IMOJEV(Sanofi Pasteur)