Where Does Japanese Encephalitis Come From?


Sudden deaths and hundreds with disabilities in children younger than 15 year sold due to viral encephalitis have been reported across the Southeast Asian countries and all regions in the Philippines as well. The outbreak has been confirmed by the World Health Organization (WHO) and have estimated that there are currently 3 billion people at risk for JE, living in JE-prone areas, including 24 countries in the Southeast Asia and Western Pacific regions. The virus  can cause inflammation of the brain, leading to high fever, headache, fatigue, vomiting, confusion, and in severe cases, seizures, spastic paralysis, and coma. It could also mimic a stroke, as was the case reported in Davao during the second half of 2016. There is no specific treatment for this disease. Japanese Encephalitis (JE) is a leading cause if viral encephalitis in Asia is fatal in 20 to 30% cases and among those who survive, 30% to 50% suffer from permanent disabilities.

Where Does Japanese Encephalitis Come From?

Japanese Encephalitis is primarily a rural disease. Transmitted by the mosquito vector Culex tritaeniorhynchus via a vertebrate host mostly pigs or wild birds. Up to 3% of mosquitoes may be infected in endemic areas. The species is found in rural and agricultural areas particularly in flooeded rice fields and piggeries. However, an epidemiologic study conducted by Dr Anna Lena Lopez of the National Institute of Health (NIH) published in 2015, showed that the virus circulates in all the regions of the Philippines, including urban areas like Metro Manila.

How severe is this virus?

Studies conducted by the National Institute of Health (NIH) showed that although majority of cases occur in children younger than 15 years of age, adults remain at risk, with 15% of cases occurring in individuals older than 18 years. In tropical areas, disease can occur year-round. Data from the Department of Health (DOH) Epidemiology Bureau surveillance system revealed that for 2016, among 875 acute meningitis-encephalitis suspected cases reported as of August 2016, 119 (14%) were laboratory-confirmed for JE.

Prevention is key

Since no cure for the disease exists, the most effective and cost-efficient form of prevention is vaccination. However, the JE vaccine requires multiple doses, which has been a significant barrier in past immunization campaigns. In resource-limited settings, high delivery and storage costs act as financial obstacles for vaccine administration. Additionally, the three-dose regiment compromises compliance rates for individuals unable to return to health care facilities for numerous dosages.

In the past, chemical control of vector populations with the use of pesticides was successful in breaking the transmission cycle. However, this is now only considered a short-term solution due to increased levels of insecticide resistance. Here are few things you can do to prevent the mosquito bites:

  1. Search and destroy mosquito breeding places
  2. Use self-protection measures
  3. Seek early consultation for fever lasting more than 2 days
  4. Say Yes to fogging when there is an impending outbreak
  5. Spread awareness to your fellow parents, students, neighbors about this virus!
  6. Ask your Pediatrician now about the vaccine!