This is a mosquito acquired flavivirus infection that occurs in
least 35,000 cases with 10,000 deaths are reported yearly.
virus is similar to Yellow Fever and other flavivirus.
Most infections are not symptomatic.
in 250 infections cause illness after 5-15 days of incubation. Illness
begins with a high fever, changes in mental status, gastrointestinal
symptoms, and headache and followed by disturbances in speech, gout
or other motor problems.
progress to stupor and coma. 5-30% of cases are fatal and 1/3 of
survivors may have neurological injury.
of Japanese Encephalitis is mostly supportive for affected people.
Japanese Encephalitis Vaccine
Japanese Encephalitis Vaccine is used to protect local populations
in Asia who are mostly at risk.
such as military personnel or expatriates (people who live as residents
during a transmission season) may consider the vaccine.
most Asian countries the peak Japanese Encephalitis season lasts
about 5 months and traveller's need only be vaccinated if at high
risk during that time.
factors for traveller's included:
1. Travel to endemic country
2. Travel during transmission season
3. Travel to rural areas (worse in rice paddies or near pig farms)
4. Extended period of residence or travel >4wks.
5. Advanced age 6. Pregnancy (risk to developing fetus)
2. Protective clothing
3. Residence in air-conditioned or well-screened areas
4. Permethrin mosquito nets
The Japanese Encephalitis vaccine is given in 3 dose administered
at 0,7, and 14-21 days, with a booster at 3 years. Side effects
of vaccination include local redness and soreness at vaccination
site, low grade fever, and muscle aches. Allergic reactions to JEV
have occurred up to 20-336 hours after vaccination, which are treatable
with Corticosteroids and antihistamines.
In conclusion, Japanese Encephalitis is extremely rare in travellers
but may be indicated in select people.
Japanese Encephalititis Links: