Acute Encephalitis Syndrome (AES)

Why in News?. A 42-year-old woman in Malappuram, Kerala, has recently tested positive for Nipah virus. She  was diagnosed with Acute Encephalitis Syndrome (AES).

Relevance : UPSC Pre & Mains

Prelims : Acute Encephalitis Syndrome (AES)/ insecticide-treated nets (ITNs

Mains :  GS 1/GS 2 – Social Issues/ Health)

About the Acute Encephalitis Syndrome (AES):

Acute Encephalitis Syndrome (AES)

Acute Encephalitis Syndrome (AES) refers to a clinical condition characterized by acute-onset fever and neurological symptoms such as mental confusion, disorientation, delirium, or coma. It is a major public health challenge, particularly in India, where outbreaks are common in certain regions.

Causes:

AES can be caused by various pathogens, including:

Viral Causes:

• Japanese Encephalitis Virus (JEV) is the most common cause in India.
• Other viruses: Enteroviruses, herpes simplex, and Nipah virus.

Bacterial Causes:

• Leptospirosis, scrub typhus, and tuberculosis.

Fungal Causes:

• Rare, but can occur in immunocompromised individuals.

Toxins:

• Exposure to toxins from certain fruits (e.g., unripe litchis linked to hypoglycin in some cases in India).

Nutritional Factors:

• Malnourished children are more susceptible due to weakened immune systems.

Symptoms

1. High fever.
2. Altered mental state (confusion, drowsiness, or coma).
3. Seizures.
4. Severe headache.
5. Neck stiffness (in some cases).

Epidemiology in India

• Affected Regions: Eastern Uttar Pradesh (Gorakhpur) and Bihar are highly endemic.
• Seasonality: Occurs mainly during the monsoon and post-monsoon seasons.
• Demographics: Mostly affects children aged 1–15 years.

Key Challenges

1. Lack of early diagnosis and timely treatment.
2. Poor hygiene and sanitation.
3. Malnutrition among children.
4. Lack of awareness and access to healthcare facilities.

Prevention and Control Measures:

Vaccination:

• Japanese Encephalitis (JE) vaccination is key in endemic areas.

Public Health Measures:

• Improving sanitation and clean drinking water.
• Promoting mosquito control measures like the use of insecticide-treated nets (ITNs).

Nutritional Support:

• Ensuring proper nutrition in children to boost immunity.

Awareness Programs:

• Educating communities about preventive measures and early signs of AES.

Healthcare Improvements:

• Strengthening primary healthcare centers (PHCs) for early diagnosis and treatment.

Management:

• Immediate hospitalization.
• Supportive care:

• Fever management.
• Seizure control.
• Maintenance of hydration and nutrition.

• Specific treatment if the causative agent is identified (e.g., antivirals, antibiotics).

Case Study: The Muzaffarpur AES Outbreak (2019)

• Location: Bihar, India.
• Cause: Hypoglycemia linked to the consumption of unripe litchis in malnourished children.
• Outcome: Over 150 children died, highlighting the role of nutritional deficiencies and public health gaps.

Way Forward

• Strengthening surveillance systems for early detection.
• Expanding vaccination coverage.
• Implementing integrated vector management programs.
• Addressing malnutrition and improving access to quality healthcare.

About Insecticide-Treated Nets (ITNs):

Insecticide-Treated Nets (ITNs) are a widely used, effective, and affordable method to prevent mosquito-borne diseases such as malaria, dengue, chikungunya, and Japanese encephalitis. These nets are treated with insecticides that kill or repel mosquitoes, providing both a physical and chemical barrier.

Features of ITNs

1. Material: Made from lightweight, durable materials like polyester or polyethylene.
2. Insecticide Treatment: The nets are impregnated with pyrethroid insecticides (e.g., permethrin or deltamethrin) that are safe for humans but lethal to mosquitoes.
3. Types:

1. • Conventional ITNs: Require periodic re-treatment (usually every 6–12 months).
   • Long-Lasting Insecticidal Nets (LLINs): Retain efficacy for 3–5 years without re-treatment.

Benefits of ITNs:

Dual Protection:

Physical Barrier: Prevents direct contact with mosquitoes.

Chemical Barrier: Kills or repels mosquitoes upon contact.

1. Cost-Effective: Affordable for mass distribution in endemic regions.
2. Community Impact: Reduces mosquito populations and disease transmission at the community level.
3. Ease of Use: Lightweight and easy to install in homes.

Effectiveness:

• ITNs significantly reduce the incidence of malaria and other vector-borne diseases.
• Studies show a 50% reduction in malaria cases and a 20% reduction in all-cause child mortality in regions with widespread ITN usage.