The World Health Organization (WHO) recently launched a technical brief highlighting encephalitis as an urgent public health priority, in response to the growing global burden of the disease. This call to action comes at a time when India continues to grapple with both a high number of, and the under-reporting of encephalitis cases, pointing to the need, experts say for a focused national strategy to tackle the disease effectively.
Encephalitis, an inflammation of the brain, presents a complex challenge due to its diverse etiology, ranging from viral and bacterial causes to autoimmune responses.
The nature of encephalitis cases in india
According to the WHO, Japanese encephalitis virus (JEV) , a flavivirus related to dengue, yellow fever and West Nile viruses, and spread by mosquitoes, is found in 24 countries across Southeast Asia and the Western Pacific, with India carrying a considerable portion of the disease burden. The annual incidence of JE globally can reach up to 10 cases per 1,00,000 population or even higher during outbreaks. In India, several States continue to struggle with high JE incidence. As reported by the National Center for Vector Borne Diseases Control (NCVBDC), Assam recorded 669 cases and 53 deaths in 2024, making it the most affected state. Other states, such as Uttar Pradesh and Bihar, also reported a substantial case numbers.
Also, as per a report published in The Lancet, India experienced the largest Chandipura virus (CHPV) outbreak in 20 years, with 245 cases of Acute Encephalitis Syndrome (AES) and 82 related deaths reported between early June and August 15, 2024. Of these, 64 cases were confirmed as CHPV infections, 61 in Gujarat and 3 in Rajasthan. The outbreak predominantly affected children under 15 years, with symptoms such as fever, convulsions, coma, and death within 48–72 hours.
Swati Bhayana, consultant in paediatric hematology and oncology at Fortis Hospital, Gurugram said that encephalitis is a major problem in paediatric patients, with viral infections being the major cause in children under 18. “Unlike adults, who report clear symptoms like severe headaches, children show signs like irritability, vomiting, seizures, or extreme tiredness, making early detection difficult yet crucial” she said.
While the number of new reported AES cases has shown a downward trend since July 19, 2024, further transmission remains possible due to factors like the upcoming monsoon season, and flooding in some States creating stagnant water pools, which serve as prime breeding grounds for disease-carrying insects.
No national surveillance in place
Despite these figures, experts state that sporadic data points fail to capture the full extent of the issue. Neha Rastogi Panda, a leading expert in infectious diseases from AIIMS, New Delhi, said one of the most significant hurdles to tackling the encephalitis burden in India was the lack of a unified reporting system. “What we follow now is a reactionary approach rather than an action-taking one. Cases often come to light only during outbreaks. There is no homogeneous reporting, and the absence of routine surveillance means we are likely just scratching the surface when it comes to the number of cases in the country,” she said.
This under-reporting is compounded by the unavailability of rapid diagnostic tools, especially in peripheral healthcare settings, Dr. Panda pointed out, adding: “Diagnosis often relies on MRI and brain sampling. While tertiary centers may have access to cerebrospinal fluid (CSF) testing and viral DNA analysis, such facilities are scarce in rural areas.”
Dr. Panda stressed the need for robust symptom-tracking systems. “We need to train frontline health workers to recognise early signs like sensitivity to light or sound, persistent headaches, or sudden behavioural changes so they can alert cases quickly,” she said.
She also noted the importance of mass vaccination drives, particularly for JE, and improved access to antiviral treatments. “Ninety per cent of viral encephalitis cases are self-limiting, but for the rest, timely antiviral treatment can be life-saving. Accessibility and affordability of these treatments must be ensured,” she added.
These infections spread fast in children with low immunity. So, early suspicion and diagnosis are key to preventing the spread to the brain, said Dr. Bhayana. “Once encephalitis hits a child, their developing brain is at risk and they may suffer with issues like permanent seizure disorders, or hemiparetic attacks. One missed infection now could mean 40 years of debilitated life,” she said.
Prevention, the need of the hour
A more proactive approach to tackling the encephalitis burden would include prevention, said P. Vijayashankar, neurologist at Apollo Hospitals, Chennai. “We don’t have a separate programme for encephalitis like we do for tuberculosis, for instance. We do have a JE vaccination programme, especially in high-risk regions like the Northeast and coastal areas, but for other forms of encephalitis, prevention remains difficult due to a lack of awareness and diagnostic gaps,” he explained.
Mosquito control, he emphasised, could serve as a crucial preventive measure: regular anti-larval operations, proper waste management, and public education about avoiding water stagnation during monsoons, could all go a long way. “There needs to be mass education on the basics about how viruses spread, what symptoms to watch for, and the significance of vaccination. A targeted public health campaign could help bridge this gap.”
A dedicated encephalitis prevention and control programme, separate from the existing vector-borne disease framework, experts said, would streamline diagnosis, improve vaccine coverage, and strengthen surveillance and eventually help decrease the disease burden in the country.
Published – February 28, 2025 06:00 pm IST
