I have been contacted by many parents on the Island regarding the current Japanese Encephalitis vaccine program being offered at all schools here.


It is unclear why this program has been offered, as despite contacting several doctors at Sanglah and in general practice, no one has heard of any current cases of the disease. However recent data suggests that Japanese Encephalitis numbers are on the rise. WHO figures show 22 cases were reported on the Island in 2015, not a lot really, however it is quadruple the cases reported in 2014. While cases are relatively few Japanese Encephalitis is of some concern due to the severity of the disease.


What Is Japanese Encephalitis?

J.E. is a rare but serious viral illness that affects the brain. It primarily affects children between the ages of 2-10 years, the elderly, or individuals with lowered immune systems. Case fatality rates range from 0.3-60% (average 30 %), and approximately 30% of those survivors will be permanently brain damaged in some way.


How does Japanese Encephalitis present?

Some people that are exposed to the disease will have very mild, or no symptoms at all. Those people will not go on to develop serious consequences of the disease; indeed they will probably never know that they had the disease.


Those that suffer severe acute infection would show any or all of the following signs:

  • Abrupt onset of high fever.
  • Headache.
  • Loss of appetite.
  • Pain behind the eyes.
  • Neck stiffness
  • Disorientation or stupor.
  • Convulsions or twitches / tremors.
  • Coma.
  • Paralysis.




How do people get Japanese Encephalitis?

J.E. is spread by vector transmission, the Culex Mosquito being the carrier. It cannot be transmitted directly from one person to the next, (i.e. you cannot get it from touching or kissing an infected person). Mosquitoes become infected by feeding on pigs or wild birds infected with the J.E virus. Infected mosquitoes then transmit the virus to humans during the feeding process. The Culex mosquito typically inhabits rice paddies, and other waterways. This mosquito is essentially an outdoor mosquito, and they are most active in the late evenings or at night. Not all Culex Mozzies           are carriers of the disease. Only mosquitoes that have been infected can infect you.


The Vaccine

A vaccine is available against the J.E. virus. The primary course of the vaccine is said to last approximately 2 years, therefore most authorities recommend single booster shots at 2-year intervals following the primary course.


There have been nasty side effects reported following injection with the J.E. Vaccine. About 0.6 % of patients have developed severe rashes and swelling immediately after the vaccine and up to 10 days after receiving the vaccine. It is wise to remain close to medical facilities for up to 10 days after the last dose. (No remote area travel in this period). The good news is that the vaccine has a high efficacy. This means that once the course has been completed, it gives a high (almost 100%) immunogenic response. It is very effective.


I usually only recommend the vaccine for anyone that may have a pig farm close their home. As to whether you accept the vaccine for your child is ultimately your decision. Apparently the free vaccine being offered in schools under the Government program is from China. (The Chengdu Institute of Biological Products). International SOS does stock an alternative JE vaccine. (I believe their vaccine is made in Thailand). If you live next to a pig farm or bird sanctuary I would recommend this vaccine for all family members.


So…If I do get Japanese Encephalitis, how is it treated?

Firstly, there is no curative treatment for J.E. (i.e. No magic pill, injection etc. that will cure it). J.E. is treated symptomatically by reducing the fever, analgesics for headache, sedatives for seizures and specialized intravenous therapy to reduce cerebral swelling.


As usual the best strategy is prevention, which starts with mosquito control.


How do we prevent the spread of J.E.?

Firstly, don’t invite this troublesome insect into your area by providing it with ideal breeding grounds.


  • Make sure that your garden and surrounding area are free of water catchments, or that water containers are covered.
  • Keep larvae eating fish, such as guppies, in ponds.
  • Use chemical larvicides in ponds, drains or other water catchments (e.g. Abate).
  • Remove garbage or unnecessary pots, bottles, cans etc from the garden area.
  • Lush garden areas should be fogged regularly in the monsoon season.


…and secondly, don’t get bitten!


  • Mozzie plug-ins or vapor mats can be used indoors in the early mornings and late afternoons during the wet season.
  • Mosquito nets and screens can be used in problem areas. Babies should always be protected by cot, or pram covers.
  • Wear long sleeved, loose light colored clothing while walking in garden areas.
  • Personal repellants may be used; however, they should be used with caution in the very young, or the elderly.


Kim Patra is a qualified Midwife & Nurse Practioner who has been living and working in Bali for over 30 years. She now runs her own Private Practice & Mothers & Babies center at her Community Health Care office in Sanur.

Kim is happy to discuss any health concerns that you have and may be contacted via email at balikim2000@gmail.com, or office phone   085105-775666 or https://www.facebook.com/CHC Bali


Copyright © 2018 Kim Patra

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