Why Japanese Encephalitis remains such a threat in Karbi Anglong

Nestled in Assam’s picturesque landscape, the Karbi Anglong district is a study in contrasts. While the lush greenery surrounding the region offers a serene backdrop, it also provides a perfect breeding ground for the mosquitoes that carry Japanese Encephalitis (JE), a deadly disease that silently stalks the region.

From summer through the monsoons and beyond, this vector-borne illness poses a serious threat, compelling doctors into a constant battle to save lives. 

For many families, the disease strikes without warning. It was high fever and disorientation, followed by a seizure, that made the parents of 2.5-year-old Purthimi Timungpi rush to Diphu Medical College and Hospital (DMCH). They were unaware of the lurking danger until their daughter was diagnosed with JE, a name they had never heard before. 

Purthimi’s story is not unique. Like her parents, many patients —including Robika Teronpi (21) and Minoti Das (50)— had no prior knowledge of the disease. 

Why Karbi Anglong is an ideal Breeding Ground

Japanese Encephalitis is a viral disease that can cause inflammation of the brain. The virus is spread to humans by the bites of infected mosquitoes, primarily the Culex species. The mosquitoes get infected by feeding on animals, especially pigs and wading birds, which act as amplifiers. Humans are called a dead-end host. 

The hot and humid climate of Karbi Anglong, combined with its vast paddy fields and other stagnant water sources, creates an ideal environment for these mosquitoes to breed. Rice cultivation, which requires flooded fields, and traditional pig farming significantly contribute to the high mosquito population.

“The JE carrying mosquito vectors are essentially night biters, preferring the duration of dusk to dawn, but they may bite at any time of the day,” says Dr. Kallol Bhattacharjee, Head of Medicines at Diphu Medical College and Hospital (DMCH).

Dr Lokajeet Baro, Head of Paediatrics, DMCH, states that cases predictably rise in late June, peak in July and August, and then subside. 

“I have observed a consistent trend in patient cases, with no significant increase or decrease so far this year as compared to the last five years. Though the number of JE cases tends to increase during the summer and monsoon season.”

A High-Stakes Battle for Healthcare Workers

Medical staff at DMCH are on the frontlines of this fight, and they are the hope for the people of this region. This year, the district recorded 33 JE cases, resulting in two deaths, according to data from the National Health Mission (NHM). At DMCH, 10 of the 27 pediatric patients admitted with Acute Encephalitis Syndrome (AES)—a broader term for brain inflammation—tested positive for JE (both serum and CSF positive), with one fatality. Among 15 adult AES cases, five were confirmed JE.

AES encompasses symptoms caused by multiple factors, such as bacteria, viruses, parasites, etc. “JE is part of a bigger umbrella that is AES… The presentation is quite similar,” explains Dr. Puja Das, Senior Resident, Pediatrics, DMCH.

While heavy monsoon rains wash away the larvae, this doesn’t eliminate the risk. Dr. Bhattacharjee, on the other hand, observes that cases peak in the post-monsoon months, especially in mid-September, and usually last for 2-3 months. He attributes this to the abundance of stagnant waters in wet paddy fields.

“One-third of the adult AES cases tested positive for JE. The good part is that so far in 2025, we (the Medicine department) haven’t had any deaths from AES. While this is a very positive trend, the situation can change at any time,” said Dr. Bhattacharjee.

The classical symptoms of JE in children or adult patients are fever, prolonged or short duration, acute onset of change in the mental state, like disorientation, and/or seizures. “In many cases, the children were not able to recognise the parents (as a result of disorientation), their activity level decreased, and they experienced convulsions,” Dr. Das stated.

The patients may not experience all the symptoms. Some patients can have mild infection and be asymptomatic, as was the case with Minoti. She developed a high fever, and her blood pressure shot up the night before her scheduled surgery. A subsequent test revealed she was positive for JE. 

Her son Bijoy Das said, “Despite the positive result, she showed no other symptoms of the illness. After four days of observation without any fever or other issues, she was discharged.”

While many patients are admitted with symptoms of AES, only a few are ultimately diagnosed with JE. A positive result on both cerebrospinal fluid (CSF) and IgM-capture ELISA tests is required for a final diagnosis. 

“A definitive JE diagnosis depends on laboratory positive results, as specified by state guidelines. If the patient shows symptoms of JE, but the tests are negative, it is classified as AES. Regardless of the final diagnosis, the treatment protocol remains the same for all patients with AES symptoms,” said Dr. Baro.

“A significant portion of our management is to treat the child symptomatically, and the dosages are based on the weight of the child,” said Dr. Das.

Early Diagnosis

Both the HoD’s stressed on “early diagnosis and early treatment for early recovery” and better outcomes. But many people, due to ignorance, resort to alternative or over-the-counter medications. This delay has proven to be disastrous in many cases in the past. 

Purthimi’s father, Protap Timungpi, initially gave her medicine for fever from a pharmacy, which provided temporary relief. But the fever returned, escalating to disorientation and seizures. By the time they reached the hospital, her condition was critical, requiring a 34-day stay.

Not many were as lucky as Purthimi and lost the battle. “Patients should be brought to the hospital within 24-48 hours of experiencing high-grade fever, altered sensorium, and/or seizure,” Dr. Baro emphasizes. “When they delay coming, the brain gets damaged. If they come early, sequelae can also be reduced. Once the brain is damaged, there is no recovery. The chances of death increase if they come late to the hospital.”

Post-JE sequelae refer to the long-term, lasting neurological, cognitive, and behavioural complications that a patient can develop.

Patients at Diphu Medical College and Hospital who need a Neurology consultation are often referred to Guwahati Medical College and Hospital. This creates a significant challenge for families, who not only face the financial strain and a potential language barrier but also the fear of traveling to a large, unfamiliar city and hospital.

“We do everything in our capacity to prepare for the patient transfer and make it easy for them, but their fear is often a major obstacle.  They instead prefer going to Dimapur,” said Dr. Baro.

Children are more susceptible to getting infected due to low immunity, while adults are more exposed to mosquitoes because they work outdoors in fields and raise pigs.

A significant and recurring problem is the widespread lack of knowledge amongst the masses, especially the people living in the remotest hilly areas, about JE, its symptoms, and how the disease gets transmitted.  

Although Protap does not rear pigs, the practice is common in their neighborhood as well as in the district.  Even after his daughter’s recovery, Protap, a daily wage labourer, does not have much knowledge about the disease.

The Vaccination Imperative

Despite the availability of JE vaccines for children, many are not immunized. Of the 27 pediatric patients with AES, seven were not immunized, including the four critical patients (one JE and three AES), who died. There is a drop-off in vaccination adherence after the initial three months, with parents skipping the later JE and measles vaccines.

“We have observed that those children who were not immunised and were infected with the JE virus have died. I have mentioned it to our Joint Director of Health. The vaccinated patients were stable after treatment and discharged within 7 to 10 days,” said Dr. Baro. 

There is a schedule for JE vaccines. The children have two dosages, one is given during the 9th month, followed by another between 16-18 months. There are various government-run immunization centres across the district.

“There is no alternative to vaccines to prevent this dangerous disease, which has a high mortality rate. Even with Auxiliary Nurse Midwives (ANMs) conducting household visits, many people still don’t get vaccinated. It’s a mystery to us why they don’t get the vaccines. I wonder if they just aren’t aware of the risks,” said Dr. Baro. 

Vaccinated individuals who are bitten typically by infected mosquitoes have less severe symptoms, which in turn helps lower the overall number of JE cases and deaths. While there is no specific cure for JE, patients can recover well with supportive care.

Dr. Bhattacharjee pointed out that the status of adult JE vaccination is “very poor”. Of the 15 adult AES cases at DMCH, only one patient was vaccinated. 

“It is of utmost importance to vaccinate against JE on a priority basis, especially of children, the elderly, and vulnerable populations. Apart from multi-dose vials, single-dose vials of the JE vaccine are also available, which are a convenient option for individual patients,” said the Head of Medicines. “However, two doses must still be administered 28 days apart, typically into the deltoid muscle, based on a physician’s discretion.” 

The lack of education is a stumbling block in creating public awareness about JE. This knowledge gap can make it difficult for healthcare workers to communicate with family members and explain a patient’s condition. “Patients arrive in critical condition. After the doctor explains the situation, we also speak with the family, but they don’t immediately comprehend how dire things are. It’s only later that the gravity of the situation sinks in for them,” said Analika Jedong, Nursing sister, PICU, Pediatric. 

According to Remmawii Moite, a staff nurse in the Medicine Department, it’s often difficult to gauge whether family members understand the severity of a patient’s condition. “Many times, the family doesn’t show any stress, even when we tell them the patient might die. Some people just don’t express their emotions, so we’re left wondering if they’ve truly understood.”

A Coordinated Effort for a Healthier Community

The Assam government’s health departments –National Health Mission and its agencies National Center for Vector Borne Diseases Control (NCVBDC), IDSP, amongst others- are actively working in Karbi Anglong district. They hold regular meetings to analyse the progress of each department. 

This year-intensive fogging operation was undertaken in all block PHCs, impregnation of bednets in villages of Block PHC, house-to-house intensive fever surveillance, and source reduction by domestic breeding checkers and field workers. Besides awareness meetings in villages, various activities were undertaken by different departments, Veterinary, Irrigation, PHED, Social Welfare Departments, among others, as stated by DPM NHM Karbi Anglong Amarjit Tisso.

After a JE case is confirmed, the health department takes immediate action by testing the patient’s family members. Concurrently, the NCVBDC is responsible for disinfecting the area. Other departments also take follow-up actions. Bijoy confirmed this process, stating, “After my mother’s diagnosis, medical staff came and took blood samples from our family, but we all fortunately tested negative.” 

Fogging and all other breeding preventive measures are random, prioritising the affected areas. Fund is a crucial factor behind it, said Obed Killing, NCVBDC Consultant in Karbi Anglong, who visits different areas for prevention every day. 

Nobelsom Kro, 28, of Rongkimi village, who runs a Kirana store, is aware of the vector-borne disease and takes precautions. However, he is unsure if his 13-year-old brother was vaccinated. His village has received fogging twice this year. 

Renewed Focus on Community-led Education

To combat Japanese Encephalitis, there is a critical need for greater public awareness about the disease and its causes. The solution needs a multi-pronged approach. Dr. Bhattacharjee said that increased public knowledge of other vector-borne diseases like Dengue has likely helped reduce JE cases, as the preventative measures are largely the same.

The doctors’ fraternity at DMCH plans to launch a handbook on AES. This guide, which contains scientific information and preventative measures, will be distributed to schools, colleges, and healthcare professionals. 

The most effective solution came from within the community. An active social worker like 50-year-old Menfing Rongpi of Rongnihang village has proven that grassroots efforts can make a difference.

He, along with some volunteers, goes door-to-door in their village to ensure all the children are vaccinated and educate their neighbours on personal protection and on preventive measures, which is a direct and impactful community-level initiative. 

Also Read: How Kaziranga’s insects and spiders hold the key to climate resilience