Context:

• Bihar has recorded 188 cases of acute encephalitis syndrome, with 45 deaths, since January. The cause of death in most this year has been attributed to hypoglycaemia (low blood sugar level).

What is Acute Encephalitis Syndrome (AES)?

• -AES affects central nervous system, mostly in children and young adults.
• -It starts with high fever,then hampers neurological functions causing mental disorientation, seizure, confusion, delirium, coma.
• The disease outbreak is usually reported during monsoons (June- October). But the incidence is also reported during April-June in Bihar.
• Locally known as Chamki Bukhar in the state.

What Causes AES?

• It can be caused by virus, bacteria, fungi, and a range of agents.
• Japanese encephalitis (JE) virus is the most common cause of AES in India, with union health ministry estimate attributing 5-35 per cent cases due to JE.
• But the syndrome is also caused by scrub typhus, dengue, mumps, measles, even Nipah or Zika virus.
• In several cases though the cause of AES remains clinically unidentified.

Status of AES in India:

• -According to National Vector Borne Diseases Control Programme (NVBDCP), 10,485 AES cases were diagnosed in 2018 with 632 deaths across 17 states.
• India records fatality rate at 6 per cent in AES, but the fatality rises to 25 per cent amongst children.
• Bihar, Assam, Jharkhand, Uttar Pradesh, Manipur, Meghalaya, Tamil Nadu, Karnataka, and Tripura are worst affected.

Relation between hypoglycaemia, children and AES:

• Bihar government officials claim AES is a syndrome not disease, and cause of death in these children was found to be prolonged hypoglycaemia that witnessed delayed treatment. In 2014 research paper titled ‘Epidemiology of Acute Encephalitis Syndrome in India: Changing Paradigm and Implication for Controlʼ, co-authored by six researchers, a parallel was drawn between
• Muzaffarpur and Vietnamʼs Bac Giang province where undernourished.
• Children were suffering from AES and hypoglycaemia that coincided with litchi orchards in neighbourhood.
• “The possible association with some toxin in litchi or in environment need to be documented. Methylene cyclopropyl glycine (MCPG) which has been known to be a content of litchi fruit has been shown to cause hypoglycaemia in experimental animals,” the study stated. Several children in Muzaffarpur who suffer from AES before 2014 have a history of visit to litchi orchards, the study found.
• The impact is worse on undernourished children who remain hungry for several hours.