Context

A boy, who had symptoms akin to Acute Encephalitis Syndrome (AES), died in Bihar’s Muzaffarpur district. This is the first reported AES case of 2020. In June 2019, more than 150 children died due to AES in Muzaffarpur.

About

• Acute encephalitis syndrome(AES) is a serious public health problem in India.
• It is characterized as acute-onset of fever and a change in mental status (mental confusion, disorientation, delirium, or coma) and/or new-onset of seizures in a person of any age at any time of the year.
• The disease most commonly affects children and young adults and can lead to considerable morbidity and mortality.
• Symptoms: AES complications may include memory loss, coma and even death. The signs and symptoms typically include:
  • High Fever
  • Headache
  • Vomiting
  • Confusion
  • Seizures
  • Sensitivity to light
  • Stiff neck and back
  • Memory loss
  • Problems with speech or hearing
  • Drowsiness
  • In some severe cases, paralysis and coma
• Who is affected? It mostly affects people below 15 years.
• Hotspot: AES has its endemic zones covering the Gangetic plain like states of Bihar, Assam, east UP, West Bengal and some parts of Tamil Nadu.

Causative agents of AES:

Viruses are the main causative agents in AES cases, although other sources such as bacteria, fungus, parasites, spirochetes, chemicals, toxins and noninfectious agents have also been reported over the past few decades.

• Japanese encephalitis virus (JEV) is the major cause of AES in India (ranging from 5%-35%).
• Herpes simplex virus, Influenza A virus, West Nile virus, Chandipura virus, mumps, measles, dengue, Parvovirus B4, enteroviruses, Epstein-Barr virus and scrub typhus, S.pneumoniae are the other causes of AES in sporadic and outbreak form in India.
• Nipah virus, Zika virus are also found as causative agents for AES. The etiology in a large number of AES cases still remains unidentified.

Is Litchi a contributing factor to ‘Litchi fever’?

• The fruit Litchi has nothing to with the fever. 
• However, the malnourished children do not have buffer stock of sugar in their liver, which might be a factor to more severe AES due to the presence of toxins (MCPG) in Litchi.

Background:

• 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, with a case fatality rate around 6 per cent.
• In June 2019, the epidemic was reported in five north Bihar districts. More than 600 children suffering from AES were admitted in several hospitals.
• Locally known as Chamki Bukhar, it has claimed the lives of more than 500 children in the previous decade.
• The most affected areas comprised Muzaffarpur, Vaishali, Sitamarhi, Samastipur, Sheohar and East and West Champaran.