Japanese Encephalitis: How to combat the deadly disease

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Japanese Encephalitis epidemics cases are reported from many parts of India however, it is highly endemic in Eastern Uttar Pradesh.


  • Currently, the virus is spreading its deadly sting in Uttar Pradesh’s Gorakhpur, where 70 children have lost their lives due to the infection.
  • Doctors in endemic region in U.P. have found cases with similar symptoms but without the virus, leading to some debate over the cause of the disease.
  • According to a report by the Directorate of National Vector Borne Diseases Control Programme (NVBDCP), 26,686 cases of encephalitis were reported in Uttar Pradesh between 2010 and August 2017.
  • Of this, 24,668 cases were of Acute Encephalitis Syndrome (AES) and 2,018 of Japanese Encephalitis (JE).
  • Out of those reportedly suffering from AES, 4,093 died in the same period. On the other hand, there were 308 JE deaths registered in the state — 15 percent of the total people who suffered from JE between 2010-2017.

What is Japanese Encephalitis?

  • Japanese Encephalitis (JE) is a mosquito-borne viral infection of the brain.
  • The virus appears to have originated from its ancestral virus in the mid-1500s in the Indonesia-Malaysia region and evolved there into different genotypes later.
  • As per the World Health Organisation (WHO), the disease occurs in many parts of Asia with an estimated 68,000 clinical cases every year.
  • JE is one kind of encephalitis which falls under a spectrum of disease called Acute Encephalitis Syndrome (AES).

What are the causes of JE?

  • It is the inflammation of the brain caused by a virus – the JE virus – which is transmitted by female Culex mosquitoes to human beings.
  • The first case of JE was documented in 1871 in Japan.
  • This virus mainly survives in pigs, ardeid birds and in mosquitoes.
  • JE primarily affects children. Most adults in endemic countries have natural immunity after childhood infection, but individuals of any age may be affected.
  • Monsoon being the breeding season for the mosquitoes, the case of AES and JE usually increase during the rainy season.

Geographical distribution:

JE occurs in a large number of countries of Asia, including Cambodia, China, Indonesia, Japan, Laos, Malaysia, Myanmar, Philippines, Korea, Thailand, Vietnam, South-eastern Russian Federation and the Indian subcontinent. In recent decades, JE has gradually spread to previously non-affected Asian regions.

Affected regions in India:

  • In a document released by the Indian Council of Medical Research, it has been stated that JE affects children below 15 years in south Indian states, whereas it affects people of all age groups in north India.
  • Uttar Pradesh and Bihar are the two states which have witnessed an increasing number of encephalitis-related deaths over the past few years.
  • The bulk of deaths, nearly 90% in the last five years due to acute Encephalitis Syndrome (AES) including Japanese Encephalitis, were in four states: Uttar Pradesh, Assam, West Bengal and Bihar.
  • While Japanese encephalitis virus continues to be one of the most common causes of acute viral encephalitis, Eastern equine encephalitis virus (EEEV), Hendra virus (HeV), enteroviruses (ENV), Chandipura virus (CHPV), Nipah (NiV), Kyasanur forest disease (KFD), Herpes simplex, poliovirus and measles virus are among the various other diseases related to it.
  • At least 80% of the cases of Acute Encephalitis Syndrome in India have mostly been identified in Uttar Pradesh, Assam, Bihar, Karnataka, Uttar Pradesh and Tamil Nadu.


  • It can present with fever, headache, vomiting, fits and can have rapid progression to disorientation and even coma over a span of hours or days.
  • If the patient survives the acute stage, long-term sequelae in the form of permanent neurological damage can occur.
  • In an area where encephalitis is known to occur, it is important to seek medical advice at the onset of any of these symptoms.
  • The incubation period of JEV is 2 to 15 days.
  • A vast majority of infections are asymptomatic, while only 1 in 250 infections develops into encephalitis.
  • Mental status changes, neurologic symptoms, weakness, and movement disorders might develop over the next few days.
  • Seizures are common, especially among children.

Preventive measures:

  • Spreading awareness about a potentially fatal disease like Japanese Encephalitis is essential
  • The mosquitoes that transmit the virus to human beings live in dirty stagnant water, paddy fields and ditches.
  • If measures are taken to eliminate the proliferation of these mosquitoes, especially after the onset of monsoon season, then the spread of the virus can be curbed to some extent.
  • Taking personal precautionary measures against mosquito bite is essential. This can be achieved by wearing fully covered clothing and using mosquito repellents.
  • Presently, there is no particular cure for Japanese Encephalitis.
  • Treatment involves supporting the functions of the body as it tries to fight off the infection.
  • Rest, fluids, and use of pain relievers and medication to reduce fever may relieve some symptoms.
  • People traveling to high-risk areas should take precautions to avoid mosquito bites to reduce the risk for JE.
  • Reduce exposure to mosquitos during peak hours (dawn and dusk).
  • People who are infected should avoid being bitten by mosquitoes while they are unwell
  • Early case detection and treatment

JE Vaccine:

  • An effective vaccine is available for Japanese Encephalitis since 2006.
  • This vaccine is not recommended to be given as part of the national immunization schedule. But two doses of the vaccine are recommended in children residing in endemic areas under 18 years of age.
  • This vaccine is also recommended for individuals travelling to areas with higher number of cases of Japanese Encephalitis, with two doses of vaccine completed at least one week before travelling.
  • In our country, with enough anti-vaccine campaigns, making vaccines available for children and adults in endemic areas and motivating people to get vaccinated looks like a Herculean task.
  • Safe and effective JE vaccines are available to prevent the disease.
  • JE vaccine is recommended for people who are traveling to endemic areas to reduce the risk of the virus and other mosquito-borne infectious diseases.
  • WHO recommends that JE vaccination be integrated into national immunisation schedules in all areas where JE disease is recognised as a public health issue.

Related facts:

  • The first case of Japanese encephalitis viral disease was documented in 1871 in Japan.
  • The incubation period of JEV (time from infection until illness) is typically 5-15 days, but 1 in 250 infections develop into encephalitis.
  • According to CDC, among patients who develop encephalitis, 20% – 30% die.
  • Although some symptoms improve after the acute illness, 30%-50% of survivors continue to have neurologic, cognitive, or psychiatric symptoms.
  • The WHO says that children are the worst-affected form the Japanese Encephalitis as most adults have immunity against the disease.
  • 24 countries, including India, in the WHO South-East Asia and Western Pacific regions have endemic JEV transmission, exposing more than 3 billion people to risks of infection. These are the worst affected countries

Gorakhpur tragedy:

Recent case:

  • Two days ago, the nation woke up to disturbing news of the death of 60 children within 48 hours at a government-run hospital in Gorakhpur.
  • The shocking death of over 60 children within a week in Uttar Pradesh’s Gorakhpur district has raised alarms reflecting the failed apathy of the medical condition of the state.
  • Administration has maintained that the deaths occurred due to Japanese encephalitis virus, and case of Acute Encephalitis Syndrome (AES).

Challenges in combating JE:

  • Lack of reliable data and research
  • Lack of accessibility to public health care.
  • When it comes to public spending on healthcares, India is lags behind abysmally.
  • Research by medical journal Lancet showed that India ranked 154 out of 195 countries in terms of healthcare access, far behind countries like Bangladesh, Nepal, Ghana and Liberia
  • Asia’s third-largest economy spends about 1 percent of its gross domestic product (GDP) on public health, compared with 3 percent in China and 8.3 percent in the United States.
  • India is even superseded by Uzbekistan (10.7 percent), Tanzania (12.3 percent), Kenya (12.8 percent), and Nicaragua (24 percent).
  • A survey by a team of researchers from the Indian Council of Medical Research (ICMR) in 2015 found that 25 percent of children surveyed in Deoria, Kushinagar, Gorakhpur and Maharajgunj districts of the Gorakhpur division did not receive the JE vaccine, while only 56 percent were administered both doses of the vaccine.
  • Lack of infrastructure facilities in hospitals.
  • Lack of unclear data on disease burden
  • Lack of access to clean water and toilets.
  • In March, the State government launched a JE vaccination drive in 38 districts in UP. But it was not supplemented with access to clean water and sanitation.
  • The efficacy of the JE vaccine is between 85-90%.
  • While India was facing trouble in importing JE vaccine from China, the government took proactive measures including a high level delegation meeting with Chinese officials to resolve the issue at the earliest.


Government’s steps:

  • The Government of India introduced the JE vaccine in high priority areas including Uttar Pradesh.
  • JENVAC was the first vaccine manufactured in the public-private partnership mode.
  • The Ministry of Health and Family Welfare was declared the nodal agency for the overseeing the programme.
  • Large vaccination campaigns were held in the country’s 11 most affected districts in 2006, 27 districts in 2007, 22 districts in 2008 and 30 districts in 2009.
  • JE vaccines were introduced under the Universal Immunization Programme. They were to be administered to infants in two doses between 9-12 months and 16-24 months.
  • UP chief minister Yogi Adityanath, launched a massive immunisation campaign in 38 districts across the state to combat the deadly Japanese Encephalitis (JE) that claims hundreds of lives each year
  • The Swachchh Bharat campaign is being linked to the drive against encephalitis
  • The health ministry launched a flagship immunization programme ‘Mission Indradhanush’ to include four new vaccines. The missions, currently providing coverage against seven life-threatening diseases and will soon include vaccines for Japanese Encephalitis for adults.


The government needs to start a national programme in public private partnership mode for prevention of this deadly disease.

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