Syllabus: GS– II & V: Disaster and Disease Management

Why in the News?

Recent data from the National Centre for Vector Borne Diseases Control shows that Assam accounted for nearly 62% of all Japanese Encephalitis (JE) deaths in India between 2018 and March 2026. During this period, Assam recorded 3,767 cases and 609 deaths, the highest in the country.

What is Japanese Encephalitis?

• Japanese Encephalitis is a viral disease caused by the Japanese Encephalitis Virus (JEV), which belongs to the single-stranded RNA virus of the flavivirus group.
• It belongs to the same genus as dengue, Zika, yellow fever, and West Nile viruses.
• It was first documented in 1871 in Japan, hence the name Japanese Encephalitis.
• It spreads through the bite of infected female Culex mosquitoes, mainly Culex tritaeniorhynchus.
• The virus is zoonotic in nature and mainly circulates between mosquitoes, pigs and water birds.
• Humans are accidental hosts and generally do not transmit the disease further.
• Severe infection can cause inflammation of the brain (encephalitis), paralysis, coma and death.
• At present there is no specific antiviral therapy for Japanese Encephalitis and is treated through supportive care.
• Safe  and effective vaccines exist (inactivated Vero cell-derived e.g., IXIARO, JENVAC, live attenuated e.g., SA 14-14-2, live recombinant e.g., IMOJEV) for preventing JE. 
  •   Several of these vaccines are WHO-prequalified.
• WHO recommends JE immunization where it is a public health priority, with strong surveillance and a one-time catch-up at introduction.

Why is Assam Highly Vulnerable?

Assam’s ecological and climatic conditions create an ideal environment for JE transmission:

• Extensive paddy cultivation provides breeding grounds for mosquitoes.
• High rainfall and annual floods increase stagnant water bodies.
• The State has a large pig population, which acts as an amplifying host for the virus.
• Warm and humid climatic conditions favour mosquito multiplication.

Key Facts and Trends

• Assam reported 642 cases and 161 deaths in 2019, one of the worst outbreaks.
• In 2024, the State recorded the highest number of cases (670) during the review period.
• Between 2018 and 2026, the rest of India recorded 376 deaths, compared to 609 deaths in Assam alone.
• Assam contributes nearly half of India’s total Japanese Encephalitis burden.

Government Measures

National Programme

• The disease is controlled under the National Vector Borne Disease Control Programme, now integrated into the National Centre for Vector Borne Diseases Control.

Key Interventions

• Mass Japanese Encephalitis vaccination campaigns.
• Surveillance and early detection systems.
• Vector control through fogging and source reduction.
• Public awareness programmes.
• Strengthening of healthcare and referral facilities.

Way Forward

• Expand adult vaccination in high-risk districts.
• Strengthen mosquito control and pig management strategies.
• Improve early diagnosis and referral systems.
• Integrate climate and disease surveillance for better forecasting.
• Enhance community awareness, especially before the monsoon season.

Conclusion

Japanese Encephalitis remains one of Assam’s most serious public health challenges. While vaccination and surveillance have reduced mortality in some years, recurring outbreaks highlight the need for sustained public health action. Protecting vulnerable populations through prevention, awareness and timely treatment is essential for reducing the disease burden.

Exam Hook – Key Takeaways

• Japanese Encephalitis is caused by a virus transmitted by Culex mosquitoes.
• Pigs and water birds are important hosts in the transmission cycle.
• Assam accounts for around 62% of India’s JE deaths (2018–2026).
• Vaccination remains the most effective preventive measure.

Mains Question

Discuss the factors responsible for the high prevalence of Japanese Encephalitis in Assam. Suggest measures to reduce the disease burden in the State. (150 words)

One-Line Wrap

Assam continues to bear the highest burden of Japanese Encephalitis in India due to favourable ecological conditions, making vaccination, surveillance and vector control critical public health priorities.