Muzaffarpur facing Acute Encephalitis Syndrome
As many as 66 children have died due to Acute Encephalitis Syndrome (AES) in Muzaffarpur district of Bihar, officials said.
A total of 55 patients died at Shri Krishna Medical College while 11 of them died in private Kejriwal hospital in Muzaffarpur. Till now over 130 have been hospitalised in the district.
District Magistrate of Muzaffarpur on Friday said that for students till class eight, schools will remain closed till June 22. And for students in higher standards, classes will be held only till 10.30 am.
The health department, meanwhile, has issued a fresh advisory for the affected districts prepared on the recommendation of the central team.
The central team has stressed the need for research and follow-up of the patients.
Encephalitis is a viral disease, which causes mild flu-like symptoms such as high fever, convulsions and headaches and has been claiming lives in the district for the past few weeks.
Muzaffarpur is the lychee bowl of India. According to the Union agriculture ministry, 300,000 metric tonne of lychees were produced from 32,000 hectare under cultivation in Bhar in 2017.
History of the illness
Every year around this time scores of children fall ill. Since January Sri Krishna Medical College and Hospital and Kejriwal Hospital in Muzaffarpur have registered 179 cases.
This is also the season when lychees ripen, are plucked and sent to mandis. According to media reports in 2014 the number of AES cases reported was 1,028 and in 2015 it was 390. Over the next two years the numbers dipped: only one in 2016 and nine in 2017.
Cause of deaths
The cause of death in children is hypoglycaemia — low levels of glucose in the blood. These children are from the poorer sections of society. Malnourishment is rampant. The children spend the day in lychee orchards eating lychees — sometimes unripe or half-ripe ones too.
There is no conclusive evidence for what causes AES. Though there have been theories linking the disease with lychee, a new scientific study insists on the link. Researchers say there is an overwhelming evidence to establish the link and the government should start treatment modalities accordingly.
The clinical features of ackee (also a fruit) poisoning and Muzaffarpur AES are similar. This includes early morning onset, encephalopathy, hypoglycemia and high case fatality. A toxic substance methylenecyclopropyl- alanine (MCPA), also called hypoglycin A, is present in unripe ackee, whose consumption leads to depletion of glucose levels in the child’s body. Since brain cells require constant supply of glucose, this depletion triggers abnormalities in brain too. A variant of hypoglycin A, namely methylenecyclopropyl-glycine (MCPG), is found in lychee and its consumption reduces glucose levels in the body.
Association of AES with lychee is important, interesting and challenging. In Vietnam and Bangladesh, outbreaks of AES have been reported in lychee cultivation areas and during lychee harvesting season7–9. Investigators in Vietnam believed that the disease was caused by some unknown virus. While in Bangladesh the disease was not thought to be infectious but was attributed to pesticides used in the orchards. Curiously, both these studies and the one from Muzaffarpur showed positive correlation between number of cases and amount of lychee harvest.
Acute Encephalitis Syndrome (AES) including Japanese Encephalitis (JE) is a group of clinically similar neurologic manifestation. It is caused by several different viruses, bacteria, fungus, parasites, spirochetes, chemical/ toxins etc. The outbreak of JE usually coincides with the monsoon and post monsoon period. It is when the density of mosquitoes increases while encephalitis due to other viruses specially entero-viruses occurs throughout the year as it is a water borne disease.
Who is affected?
- It predominantly affects population below 15 years.
- There is seasonal and geographical variation in the causative organism.
- JEV has its endemic zones running along the Gangetic plane including states of UP (east), Bihar, West Bengal and Assam, and parts of Tamil Nadu.
In India, AES outbreaks in north and eastern India have been linked to children eating unripe litchi fruit on empty stomachs. Unripe fruit contain the toxins hypoglycin A and methylenecyclopropylglycine (MCPG), which cause vomiting if ingested in large quantities. Hypoglycin A is a naturally occurring amino acid found in the unripened litchi that causes severe vomiting (Jamaican vomiting sickness), while MCPG is a poisonous compound found in litchi seeds that causes a sudden drop in blood sugar, vomiting, altered mental states leading to lethargy, unconsciousness, coma and death. These toxins cause sudden high fever and seizures serious enough to require hospitalisation in young, severely malnourished children.
Status of AES in India
AES due to JEV was clinically diagnosed in India for the first time in 1955 in the southern State of Madras, now Tamil Nadu. During 2018, 10485 AES cases and 632 deaths were reported from 17 states to the National Vector Borne Diseases Control Programme (NVBDCP) in India. It had a case fatality rate around 6 per cent. AES cases were reported mainly from Assam, Bihar, Jharkhand, Karnataka, Manipur, Meghalaya, Tripura, Tamil Nadu, Uttar Pradesh.