AES: Don’t Blame It On The Litchi

By Shreya Haridas

A seasonal spurt of Acute Encephalitis Syndrome (AES) has hit Bihar with three kids dying of the disease. Last year, the syndrome claimed 161 deaths.  Amid this scary COVID-19 lockdown, it would be good to know more about AES, and be prepared for dealing with it.

Although most affected by this syndrome are children, AES can be contracted by anyone irrespective of age group. Though the reasons for the syndrome this year has not been confirmed, previous years’ trend suggests that this could be due chemical reactions in the body due to consumption of unripe litchis. These are not contagious since it is caused due to

To start from the basics, what is Acute Encephalitis Syndrome or AES? AES is an umbrella term coined by the WHO, referring to several brain disorders (mental confusion, disorientation, convulsion, delirium or coma) or infections caused by viruses or bacteria. The Japanese encephalitis constitutes 35% of the cases in India, making it the most prevalent kind. However, some chemicals can also cause AES. This is where litchis come into picture.

How can litchis kill?

In India, AES outbreaks almost coincide geographically and temporally with the litchi season in India’s litchi paradise, Muzaffarpur in Bihar, from April to July. Bihar is one of the poorest states in India, with almost 34% of its population Below Poverty Line.

During litchi cultivation, children in the area consume as many litchis as they like. However, children from poor households, skip their dinner after having litchis and hit their beds.

When a person sleeps, the glucose and glycogen (larger packets of glucose) stored in the body is used as fuel to survive the night. This results in a glucose level drop, which is the reason why we have low blood sugar levels before breakfast in the morning. However, in a malnourished person, the blood sugar levels may fall way below normal, leading to hypoglycemia. But our brain needs normal levels of blood sugar to function. To supply this, an alternate pathway of glucose synthesis is taken, by converting fatty acids in our body to glucose.

Unripe litchis have a toxin called Methylene cyclopropyl glycine (MCPG). This chemical block this process of fatty acid oxidation, making the brain starve. This condition is called hypoglycaemic encephalopathy. This leads to seizures and very often, in death.

So naturally, the authorities blame litchis for AES, while the real culprit is malnutrition. A research paper published in Lacet in 2014, studied 104 AES affected children. In this group, 65 per cent reported they ate litchi, 52 per cent admitted to visiting a fruit orchard and 78 per cent said they did not have dinner.

Other studies have shown that most of the children affected by hypoglycaemic encephalopathy induced AES are from families staying in orchards to harvest the fruits. Also, most of the affected families are from Scheduled castes and other weak sections of the society.

Studies and reports also show that no child from well-off families has been affected till date. This implies that only malnourished children are prone to this type of AES.

However, on the bright side, such types of AES can be prevented by minimising litchi consumption and having a proper dinner. Children affected by the syndrome can be rescued by glucose correctio treatments if they are immediately rushed to the hospital.