are fleeing villages. The chamki bukhar is running faster and
it is winning the race, they say.Fear without a name
It’s a fear that has no name and no definition: Acute
Encephalitis Syndrome (AES) is a basket coinage by the
World Health Organisation (WHO) in 2008 for lethal brain
fever that hits children hard but remains elusive to doctors
and scientists. That’s because, more than 100 different types
of viruses, bacteria, parasites and fungi can cause AES symp-
toms, 50 per cent of the cases are caused by “unknown” agents
and 90 per cent have no specific treatment. Hence, patients
stay undiagnosed and untreated as the mystery killer sweeps
through its territory, counting its victims. If it is not contained
soon, India will face an unprecedented situation for which it
does not have a plan. “Basket terms are never good in science
and AES has turned into a public health conundrum,” says
epidemiologist Jayaprakash Muliyil of Christian Medical
College, Vellore, a man who has led India’s battle against in-
fections for long. “What is sad is that we
have the knowledge base and the technol-
ogy, yet we have not been able to sort it out.
This magnitude of loss is unpardonable.
We have lost our priority.”
The outbreak began in the small villages
that line the ancient Sarayu river, just as
the tall groves of litchi trees lit up with
fiery red fruits. Every summer children
run around the orchards, play all day long,
pick up fruits from the ground, and eat as
many as they can. And every summer
since 1995, the outbreak flares. Children
die painful, unexplained deaths, racked
with convulsive seizures, stiff limbed and
disoriented—signs of brain inflammation
(see graphic). What do they die of? Scien-
tists have not been able to figure out the root cause yet.
The world of science is scanning for evidence. Hypothesis
and theories are being reviewed. All stripes of investigating
teams have come on board, to carry out field surveys, collect
biological samples, probe virological markers. And they are
all advocating theories according to their areas of interests.
Thickets of medical jargon and numbers are making the
shroud of confusion thicker. The litchi is under the scanner.
Muzaffarpur, India’s “land of litchi”, supplies the bulk of the
country’s harvest and the classiest varieties. To some, it is the
toxin, amino acid hypoglycin A, naturally found in litchis,
that causes fatal brain inflammation in undernourished
children. Don’t lab tests reveal very low blood glucose levels
caused by high concentrations of the same amino acids in
their body? Litchi scare has hit sales, affecting the very chil-
dren whose families depend on the fruit for livelihood.
Others point to six-month-old victims. Surely, they couldn’t
have eaten litchi? Nothing explains why only some children
in a village, or only one in a family, are affected and not the
others. Or why, even in July in earlier years, when all the lit-
chis have been harvested, AES cases still continue in
Muzaffarpur? With Bihar spending a mere Rs 348 per person
per year on healthcare—less than half the national average of
Rs 724—primary and community health centres often do notwork and treatment facilities are not available at places
where cases occur the most. About 91 per cent deaths are
believed to happen because the patient travels for over an
hour to reach a hospital, say yet others. Some point to pollu-
tion, ground water contamination and heat stroke, all adding
to the burden of severe malnutrition, immune deficiency and
depressed metabolic rates. Increasingly, a viral explanation
for the fatal illness in children is gaining ground.India under siege
Even as Bihar struggles to contain the outbreak, 16 children
have died of AES in neighbouring Uttar Pradesh. Rajasthan
has directed health officials to stay on alert against sporadic
cases it has witnessed since 2016. Doctors at Kolkata and
Kozhikode are warning of rising encephalitis cases from an
atypical source, while Mizoram has been in the grip of an
outbreak since January. Karnataka’s Shimoga district is still
reeling from the deadly encephalitis triggered by a little-known
virus. According to the National Vector Borne Diseases
Control Programme (NVBDCP), AES
cases have occurred typically in the rice-
belts of Assam, Uttar Pradesh, West Bengal,
Odisha, Tamil Nadu, Karnataka, Manipur,
and Tripura so long. But in 2018, about
10,485 cases have taken place across 17
states, shows NVBDCP data. AES is clearly
spreading its tentacles across India.
As scientists find ways to combat a
pathogen in the AES basket, new ones
come up to claim more lives. The first
case of AES was reported in India in 1955
from Vellore, Tamil Nadu, and the first
major outbreak in 1973 from Bardhaman
district of West Bengal. Since then, AES
and Japanese Encephalitis Virus (JEV)
have been reported from 171 districts of
19 states. But after the introduction of a JEV vaccine in 2005
and launch of surveillance guidelines by the NVBDCP, cases
have come down. “Once the incidence of JE falls, AES caused
by other neuropathogenic agents are unmasked,” says Dr
Rajnish Joshi of AIIMS Bhopal.
That’s what has happened. Coming to the fore since the
2000s is a host of microbes: Herpes Simplex virus,
Enterovirus, Nipah virus, Chandipura virus, Scrub Typhus
bacteria, West Nile Virus, the Kyasanur Forest Virus. Most of
these have not been seen as outbreaks affecting a large pop-
ulation in this country. The mechanisms that regulate them
or the vectors they use for transmission are not understood
enough. Most are not taught in medical schools. There are no
clinical guidelines for doctors on these. What’s more, there
is very little immunity against them in general population.
Hence, they pose a much more deadly threat in the future.
“Many of these outbreaks occur in hot and humid seasons,
predominantly affect children, and have a high case-fatality,”
adds Joshi. But in absence of a definite viral diagnosis for
each, it is very difficult to treat patients, he explains. This
conquest of new territories by AES and its newer forms imply
that new risks have now to be taken into account. And India
will now have to live with that threat.
Viruses, parasites and bacteria that prey on humans are mi-cover sTory
As scientists find
ways to combat
a specific
pathogen in the
AES basket, new
ones come up to
claim more lives.32 OutlOOk 8 July 2019