Introduction:
The number of child deaths in Bihar had turned the country’s attention towards Acute Encephalitis Syndrome. Thedisease has claimed over 100’s of lives. The disease most commonly affects children and young adults, damaging their central nervous system
AES:
- Acute encephalitis syndrome (AES) is characterized by an acute onset of fever and clinical neurological manifestation that includes mental confusion, disorientation, delirium, or coma
- Meningitis caused by virus or bacteria, encephalitis (mostly Japanese encephalitis) caused by virus, encephalopathy, cerebral malaria, and scrub typhus caused by bacteria are collectively called acute encephalitis syndrome.
- The disease most commonly affects children and young adults and can lead to considerable morbidity and mortality.
- The history of AES in India has paralleled with that of the Japanese encephalitis virus (JEV) since the first report in 1955 from Vellore, Tamil Nadu. The first outbreak of JEV was reported in Bankura district, West Bengal in 1973. Thereafter, sporadic cases of AES and outbreaks have been the leading cause of premature deaths due to the disease in India
Causes:
- Viruses are the main causative agents in AES cases, although other sources such as bacteria, fungi, parasites, spirochetes, chemicals, toxins, and noninfectious agents have also been reported over the past few decades. It is not vaccine-preventable.
- Japanese encephalitis virus (JEV) is the major cause of AES in India (ranging from 5%-35%).
- Herpes simplex virus, Nipah virus, Zika virus, Influenza A virus, West Nile virus, Chandipura virus, mumps, measles, dengue, scrub typhus, S.pneumoniae are also found as causative agents for AES.
Government Initiatives:
- Several government initiatives have been undertaken to educate and improve the hygiene of people living in the JE endemic zones.
- Government and non-government organizations have been instrumental in providing proper nutrition to the AES-affected population as most of the affected people belong to the lower economic strata of the society.
- There have been initiatives to help the people residing in the endemic zones for alternative professions such as giving up pig-rearing since pigs are the primary host for JE viruses. Special schools have been set up to help children challenged by clinical sequelae of JE infection.
- Vero cell-derived purified inactivated JE vaccine-JENVAC, was the first vaccine in India that received manufacturing and marketing approvals from the Drug Controller General of India. The vaccine was an outcome of public-private partnership mode between the Indian Council of Medical Research and Bharat Biotech.
Litchi fruit link:
- In 2012-2013, a two-member team headed by virologist Dr. T. Jacob John confirmed, a toxin found in litchi fruit that was responsible for causing the hypoglycaemic encephalopathy.
- In 2017, a large Indo-U.S. team confirmed the role of the toxin. The toxin is called methylene cyclopropyl glycine (MCPG).
- Early morning, there is normal tendency for blood sugar to dip, after several hours of no food intake.
- Undernourished children who had gone to sleep without a meal at night develop hypoglycaemia.
- The brain needs normal levels of glucose in the blood. The liver is unable to supply the need. So the alternate pathway of glucose synthesis, called fatty acid oxidation, is turned on. That pathway is blocked by MCPG.
- Litchi does not cause any harm in well-nourished children, but only in undernourished children who had eaten litchi fruit the previous day and had gone to bed on empty stomach.
- What precisely causes the brain inflammation is not clear. Heat and humidity could be factors, and also genetic predisposition because not all the children in a family fall ill despite the same conditions
Measures needed:
- Increase access to safe drinking water and proper sanitation facilities
- Improve nutritional status of children at risk of JE/AES
- Preparative measures to be in place before the possible outbreaks.
- Vector control :
- The preventive measures are directed at reducing the vector (mosquito) density.
- Personal protection against mosquito bites using insecticide treated mosquito nets.
- Clothing reduces the risk of mosquito biting if the cloth is sufficiently thick or loosely fitting. Long sleeves and trousers with stockings may protect the arms and legs, the preferred sites for mosquito bites. School children should adhere to these practices whenever possible.
- Repellents are a common means of personal protection against mosquitoes and other biting insects. These are broadly classified into two categories, natural repellents and chemical repellents. Essential oils from plant extracts are the main natural repellent ingredients, i.e. citronella oil, lemongrass oil and neem oil.
- The reduction in mosquito breeding requires eco-management, as the role of insecticides is limited.
- Vaccination: As per Govt. of India guidelines, 2 doses of JE vaccine have been approved to be included in UIP to be given one along with measles at the age of 9 months and the second with DPT booster at the age of 16-24 months w.e.f. April, 2013.
- Better awareness generation among children, parents through Anganwadi workers, ANMs etc.
