Brain-Eating Amoeba (Naegleria fowleri)

Why in the News?

1. A nine year old child has died and two others, including a three month old baby, were infected with Primary Amoebic Meningoencephalitis (PAM) (a rare brain infection caused by an amoeba) in Kozhikode, Kerala in recent days.
2. Kerala has recorded eight confirmed cases and two deaths in 2025 till August, with no clear link between the three recent cases in August.
3. PAM is caused by Naegleria fowleri, a free-living “brain-eating” amoeba that thrives in warm freshwater.

Key Highlights

1. Timeline and Burden:Global to Kerala
   1. Global rarity (very few cases): Since 1965, fewer than 500 PAM cases have been reported worldwide, across all continents except Antarctica.
   2. India’s first case (1971): Marked the country’s entry into the global case list.
   3. Kerala’s first case (2016): The state began reporting cases; 2016–23: eight cases
   4. Recent surge:
      1. 2024 saw 36 cases and nine deaths in Kerala
      2. 2025 till August: eight cases and two deaths, but with a state fatality rate (~25%) much lower than the global rate (~97%).
   5. The Pathogen (disease-causing organism) and Where It Lives
      1. Organism: Naegleria fowleri is a single-celled amoeba (tiny organism seen only under microscope) that lives in warm freshwater and soil, tolerating temperatures up to ~46°C (sometimes higher).
      2. Habitats: Found in lakes, rivers, pools, splash pads, surf parks, and other poorly maintained or low-chlorine water bodies.
      3. Non-communicable (not spread between people): The disease spreads only from environment to human, not human-to-human.
   6. How Infection Happens
      1. Entry route: The amoeba enters through the nose during water-related activities.
      2. Pathway: It then travels via the olfactory nerve (nerve for smell) to the brain.
      3. Effect: In the brain, it destroys tissue, causing Primary Amoebic Meningoencephalitis (PAM) (brain inflammation and infection).
      4. Risk factors: Swimming/diving in unclean water, nasal rinsing with unsafe water, and lack of chlorination raise chances.
   7. Clinical Course, Outcomes, and Treatment
      1. Early symptoms: Headache, fever, nausea, vomiting.
      2. Later stage: Stiff neck, confusion, seizures (uncontrolled fits), hallucinations, and coma.
      3. Fatality (death risk): Most patients die within 1–18 days after symptoms start.
      4. Treatment: No single effective cure exists. Doctors use drug combinations like amphotericin B, fluconazole, azithromycin, rifampin, miltefosine, and dexamethasone.
      5. Survival record: In July 2024, a 14 year old boy in Kozhikode became India’s first survivor, among only 11 survivors worldwide.
   8. Detection, Cause Under Study, and Prevention
      1. Improved testing: Kerala’s detection is better because tests for Acute Encephalitis Syndrome (AES) (a group of brain fever diseases) now also identify PAM.
      2. Different amoeba: Health officials suggest recent cases may involve another amoeba type, still under investigation.
      3. Preventive steps:
         1. Avoid warm, poorly chlorinated freshwater
         2. Use nose clips during water activities

• Use sterile (boiled & cooled/distilled) water for nasal cleansing rituals (like in religious practices).

1. Climate link: With rising temperatures and heat waves, N. fowleri grows better in warm water, raising infection chances.

Implications

1. Public Health Surveillance (systematic disease tracking)
   1. Early detection: Routine AES testing helps doctors diagnose PAM faster.
   2. Source tracking: Checking water bodies visited by patients helps locate the infection source.
   3. No contact tracing: Since PAM is not person-to-person, focus is on water environment testing.
   4. Data records: Centralized reporting improves response.
2. Water Safety and Urban Services
   1. Chlorination: Regular pool disinfection prevents amoeba survival.
   2. Closures: Shut down recreational waters during heat waves or poor chlorine levels.
   3. Religious water use: Provide treated/sterile water for rituals involving nasal cleansing.
   4. Rural safety: Monitor ponds and lakes in villages to prevent exposure.
3. Clinical Readiness
   1. Awareness: Doctors must recognize early brain fever signs that progress quickly.
   2. Drug supply: Ensure essential drugs like amphotericin B and miltefosine are stocked.
   3. Referral system: Clear path for moving patients to advanced hospitals with ICU (intensive care units).
   4. Pediatric care: Special focus on children, as most cases are in younger age groups.
4. Risk Communication (public awareness)
   1. Clear messages: Educate people to avoid unsafe water during heat waves.
   2. Simple steps: Use nose clips, keep head above water, and avoid nasal rinsing with unsafe water.
   3. Balanced awareness: Stress that the disease is extremely rare but requires urgent treatment if suspected.
   4. Tourism link: Provide advisories for swimming pools, surf parks, and festivals.
5. Climate-Health Connection
   1. Monitoring water: Check temperature and chlorine levels of public water regularly.
   2. Pathogen studies: Research whether new amoeba species are emerging in India.
   3. Drug research: Develop better medicines and treatment protocols.
   4. Policy action: Include PAM risks in climate-health policies and heatwave preparedness plans.

Challenges and Way Forward

Conclusion

The brain-eating amoeba infection (PAM), though rare, is highly dangerous due to its fast progression and very high death rate. Kerala has shown that early detection and better treatment can reduce fatalities. With climate change raising water temperatures, the risk may increase, making it urgent to strengthen water safety, hospital readiness, public awareness, and research. A balanced approach, avoiding panic but ensuring vigilance, is the way forward.