What is 'brain-eating amoeba'? 19 dead in Kerala: Causes, symptoms, characteristics

Primary Amoebic Meningoencephalitis is rare and usually occurs in otherwise healthy children, teens and young adults.

So far, 19 people have died in Kerala due to Primary Amoebic Meningoencephalitis in 2025. However, Kerala’s health minister Veena George has said there has been no cluster outbreak of the condition this year like last year.

Primary amoebic meningoencephalitis (PAM) is a disease caused usually by infection with Naegleria fowleri, a microscopic amoeba commonly called a "brain-eating amoeba." (Representational Photo)

In 2024, George said there were clusters of the disease linked to a common water source. This year so far, she confirmed that 69 PAM cases have been detected, with 19 deaths reported.

“Not clusters, single cases...we did have clusters, but not in 2025... but back in 2024, there was a cluster there because the same water source was used...here, there is no cluster, but we have cases, we have a total number of 69 cases..." she told news agency ANI.

What is Primary Amoebic Meningoencephalitis?

According to the Kerala government's health department, Primary Amoebic Meningoencephalitis is a type of ‘amoebic encephalitis’ - a rare but lethal central nervous system infection caused by free-living amoebae found in freshwater, lakes, and rivers.

Primary amoebic meningoencephalitis (PAM) is a disease caused usually by infection with Naegleria fowleri, a microscopic amoeba commonly called a "brain-eating amoeba." This infection destroys brain tissue, causing severe brain swelling and death in most cases, the annexure says.

PAM is rare and usually occurs in otherwise healthy children, teens and young adults.

The other type of amoebic encephalitis granulomatous amoebic encephalitis (GAE).

How does one contract PAM?

Primary Amoebic Meningoencephalitis develops after several days of exposure to a contaminated water source. It typically causes death within 1-2 weeks of infection.

PAM can occur in previously healthy young people exposed to warm, especially stagnant, fresh water. The disease is caused after the amoeba enters the body through the nose and not necessarily due to the consumption of contaminated water.

According to Kerala’s health department, along with swimming or diving in water bodies contaminated with Naegleria fowleri, the use of neti pots for the treatment of sinusitis has been implicated in causing the infection.

What are brain-eating amoeba’s symptoms?

The symptoms of PAM are quite similar to that of bacterial meningitis, such as headache, fever, nausea, and vomiting, making it difficult to detect it. By the time other more common causes of

meningitis are ruled out and the diagnosis of PAM is considered, it is often too late to save the patient from the cerebral edema that quickly develops and causes death.

Key characteristics of PAM:

According to the Kerala health department, these are the key characteristics of the infection caused by the ‘brain-eating amoeba’-

• PAM commonly affects children and young adults who have previously been healthy (immunocompetent).
• This disease occurs more often during the warmer months of the year and in warmer climates.
• Patients with PAM typically have a history of swimming, diving, bathing, or playing in warm, generally stagnant, freshwater during the previous 1-9 days.
• Rarely, patients with PAM may experience disordered smell or taste.
• Most often, the symptoms of PAM are indistinguishable from those of acute bacterial meningitis.
• The acute onset of PAM occurs over a period of hours to 1-2 days.
• The neuro-olfactory route provides naegleria fowleri quick access to the brain and results in impaired adaptive immune response, causing a very rapid disease course.