In News:

Kerala has reported yet another fatal case of amoebic meningoencephalitis in 2025, deepening public health concerns in the state. With this incident, Kerala’s cases linked to amoebic meningoencephalitis in 2025 have risen to 27, highlighting an emerging disease surveillance challenge. Health authorities are still investigating the exact source of infection in the latest case, as environmental exposure remains the primary risk factor.

Understanding Amoebic Meningoencephalitis

• Nature of the Disease: Amoebic meningoencephalitis, or Primary Amebic Meningoencephalitis (PAM), is a rare but rapidly progressing and typically fatal brain infection. It occurs when a free-living amoeba invades the central nervous system, causing severe inflammation and extensive brain tissue damage.
• Causative Organism: The infection is caused by Naegleria fowleri, often referred to as the “brain-eating amoeba.” This thermophilic organism is naturally present in warm freshwater bodies and moist soil.

Transmission and Environmental Factors

• The disease is not transmitted person-to-person.
• Infection occurs when contaminated water enters the nasal cavity, allowing the amoeba to migrate through the olfactory nerve into the brain.
• Naegleria fowleri proliferates in warm freshwater, particularly during summer months, in environments such as:
  • Lakes
  • Ponds
  • Hot springs
  • Poorly chlorinated swimming pools
  • Warm freshwater streams and rivers

Kerala’s warm and humid climate, combined with widespread freshwater sources, may create favourable conditions for the organism, necessitating stronger environmental monitoring and public awareness.

Clinical Presentation

Early Symptoms (1–9 days after exposure):

• Fever
• Headache
• Nausea
• Vomiting

Advanced Symptoms:

• Stiff neck
• Seizures
• Confusion
• Loss of balance
• Hallucinations
• Progressive neurological deterioration

The disease often leads to coma and death within days, making it one of the deadliest infections of the central nervous system.

Treatment and Mortality

Treatment remains highly challenging, with over 95% mortality. Some survival cases have been associated with:

• Early diagnosis
• Rapid initiation of drugs like amphotericin B and miltefosine
• Aggressive supportive care in intensive settings

However, the overall prognosis remains extremely poor due to the fast progression of the infection.

Preventive Measures

Given the absence of person-to-person transmission, prevention focuses on reducing environmental exposure:

• Avoid swimming or diving in untreated freshwater bodies, especially during warmer months.
• Use nose clips while entering freshwater.
• Ensure proper chlorination and maintenance of swimming pools.
• Avoid stirring mud or sediment in shallow freshwater areas where amoebae thrive.

In News:

Kerala’s Kozhikode district has reported three recent cases of primary amoebic meningoencephalitis (PAM), including the death of a nine-year-old girl. A three-month-old infant and another child are currently receiving treatment. Following these incidents, the state health department has issued an alert to prevent further infections.

About Primary Amoebic Meningoencephalitis (PAM):

• Definition: PAM is a rare but severe infection of the brain and its protective membranes, caused by the free-living amoeba Naegleria fowleri, popularly called the “brain-eating amoeba.”
• Transmission: The amoeba thrives in warm, fresh water, soil, hot tubs, and improperly maintained swimming pools. Infection occurs when contaminated water enters the nose, allowing the pathogen to reach the brain and meninges. Dust or soil exposure can also serve as potential sources.
• Symptoms: Include headache, fever, nausea, vomiting, sore throat, hallucinations, and neurological deterioration. PAM progresses rapidly, often proving fatal within days.
• Treatment: Early diagnosis and administration of specific antibiotics can sometimes save lives, but recovery is rare. Globally, the disease has a 97% fatality rate, whereas Kerala has reduced it to 25% due to prompt medical interventions and protocols.

Other Amoebic Infections:

• Granulomatous Amebic Encephalitis (GAE): Caused by Acanthamoeba or Balamuthia mandrillaris, GAE progresses more slowly than PAM but is equally deadly if untreated. Unlike PAM, GAE does not necessarily require water exposure for infection.

Epidemiology in Kerala:

• The first PAM case in India was reported in 1971, and Kerala’s first case occurred in 2016. From 2016 to 2023, eight cases were confirmed in the state.
• Last year, Kerala recorded 36 positive cases with nine deaths, prompting the development of the state’s first standard operating procedure (SOP) for managing amoebic meningoencephalitis.
• Notably, in July 2024, a 14-year-old boy in Kozhikode became the first Indian to survive PAM, only the 11th survivor globally.

Factors Contributing to Recent Cases:

• Increased testing for acute encephalitis syndrome (AES).
• Environmental changes, including climate change and pollution.
• Greater awareness and proactive healthcare measures, leading to earlier detection and treatment.

Why is it in the News?

A five-year-old girl from Malappuram district in Kerala who had been undergoing treatment for amoebic meningoencephalitis at the Government Medical College Hospital Kozhikode has died.

What is the Primary Amoebic Meningoencephalitis?

• Primary amebic meningoencephalitis (PAM) is a rare brain infection that is caused by Naegleria fowleri.
  • It is a free-living amoeba or a single-celled living organism.
• Naegleria fowleri lives in warm fresh water and soil around the world and infects people when it enters the body through the nose.
• Higher temperatures of up to 115°F (46°C) are conducive to its growth and it can survive for short periods in warm environments.
  • The amoeba can be found in warm freshwater, such as lakes and rivers, swimming pools, splash pads, surf parks, or other recreational venues that are poorly maintained or minimally chlorinated.

How does Naegleria fowleri infect people?

• Naegleria fowleri enters the body through the nose, usually when people are swimming. It then travels up to the brain, where it destroys the brain tissue and causes swelling.
• Notably, people cannot get infected with Naegleria fowleri from drinking water contaminated with the amoeba.
• PAM is also non-communicable.

Symptoms of PAM:

• In the initial stage, the symptoms include headache, fever, nausea and vomiting.
• Later on, the patient may have a stiff neck and experience confusion, seizures, hallucinations and slip into a state of coma.
• According to the US Centers for Disease Control and Prevention (CDC), “Most people with PAM die within 1 to 18 days after symptoms begin.
• It usually leads to coma and death after 5 days.”

What is the treatment for primary amoebic meningoencephalitis?

• As earlier reported, scientists haven’t been able to identify any effective treatments for the disease yet.
• At present, doctors treat it with a combination of drugs, including amphotericin B, azithromycin, fluconazole, rifampin, miltefosine, and dexamethasone.