Encephalitis, sure, but what's causing it?

This year, acute encephalitis syndrome, an infection from mosquito-borne Japanese encephalitis virus and other infections, has infected 1,219 and killed 330 people.

This year, acute encephalitis syndrome, an infection from mosquito-borne Japanese encephalitis virus and other infections, has infected 1,219 and killed 330 people.

HT Image

Delhi's confirmed dengue deaths this year have the national capital shaken and stirred. If you add the 7 deaths that don't make it to the MCDs' list despite hospital records showing the patient had diagnosed dengue, the toll becomes 10. People are outraged, and rightly so, at the civic agencies' and the government's inability to control the now annual outbreaks that track the monsoons each year more closely than India's Met Department.

Yet, the 330 deaths from another monsoon-shadowing outbreak in the eastern Uttar Pradesh district of Gorakhpur haven't created a ripple in any other part of the country. This year, acute encephalitis syndrome (AES), an infection from mosquito-borne Japanese encephalitis (JE) virus and other infections, has infected 1,219 and killed 330 people, mostly children under 14, in eastern Uttar Pradesh and western Bihar. While 92 deaths - 7.5% -- are attributed to JE, the cause of the rest is unidentified.

"You'll have to move the national Capital to Gorakhpur for a day for people to notice we lose hundreds of children to this disease each year," said Dr K. P. Kushwaha, professor of paediatrics at the BRD Medical College in Gorakhpur, who has been tracking the disease since the first recorded outbreak in the Gorakhpur and six surrounding districts in 1978.
"The outbreak is not so bad this year. Last year, we had 1,600 cases and 320 deaths, 131 of which from JE, the most common cause of viral encephalitis in children. The rest were suspected enterovirus (gastrointestinal) infections from contaminated food and water because of poor sanitation, but even after so many years, the etiologic agents have not been identified," said Dr Kushwaha.

AES outbreaks are a regular as the monsoons in Gorakhpur -- a paddy growing area, with clay soil and a very high water table -- since in 1978, when 2,273 people were infected and 300 died of encephalitis symptoms then believed to be caused by JE.

The worst outbreaks came almost two decades later. In 2005, JE devastated Gorakhpur and seven surrounding districts, affecting 6,061 and killing 1,123. This was followed outbreaks in 2006 that infected 2,320 and killed 528, and again in 2007, when 3,024 cases and 645 deaths were reported.

Unlike dengue, there was a vaccine against JE, so the Centre swung into action after the 2005 outbreak and carried mass vaccinations against JE in the region in 2006 and again 2011. JE vaccination was even made part of the Universal Immunisation Programme in 2013. On Friday, Union Health Minister Ghulam Nabi Azad proudly announced that India had developed an indigenous vaccine -vaccines imported from China were being used till now - to protect children from JE, but experts doubt whether this is will help end outbreaks.

Despite the vaccination drives since 2005, children - AES incidence is highest among boys less than 14 years -- continued to die. Though the number of children testing positive for JE dropped, children continued to die of AES symptoms of high fever, incoherence and disorientation, with or without seizures, followed by polio-like flaccid paralysis.

So, in 2006, JE outbreaks were renamed AES, a term used to describe the symptoms rather than the cause of the infection. The cause could be one or a combination of many. Gorakhpur is in the Terai region, where the warm, humid climate combined with paddy-fields and plenty of rain makes it an ideal breeding ground not just for mosquitoes but also bacteria, viruses and fungi. Children are at most risk because they are out playing and swimming in the innumerable ponds, which not just exposes them to mosquitoes but also water-borne infections.

"I don't know what's causing the deaths, all I know is that the paediatric wards are overcrowded and many parents leave the hospital devastated," says Kushwaha, who struggles to accommodate patients, many of whom are reach the hospital too late in the arms of their parents because they've already been struck by paralysis. The AES case fatality - number of deaths among the people diagnosed - is a high 20-25%, which is among the highest among any infection.

To a smaller degree, this holds true for Assam, Bihar, Karnataka and Tamil Nadu, the states that along with Uttar Pradesh account for roughly 80% of AES cases and deaths in India. With no specific anti-viral drugs or antibiotics available for AES and the vaccine effective only against 5-10% cases, it's imperative to solve the mystery of this monsoon brain fever striking Gorakhpur's young population.