Kerala health authorities are on high alert following a surge in cases of Primary Amoebic Meningoencephalitis (PAM), a rare but deadly brain infection caused by Naegleria fowleri, often referred to as the “brain-eating amoeba.” So far this year, the state has reported 61 confirmed cases and 19 deaths, with many of the fatalities occurring in recent weeks.
Health Minister Veena George described the situation as a serious public health concern. While previous outbreaks were largely confined to specific districts such as Kozhikode and Malappuram, recent cases have been reported sporadically across the state. Victims have ranged in age from a three-month-old infant to a 91-year-old senior citizen.
“Unlike last year, we’re not seeing clusters linked to a single water source,” said the Minister. “These are isolated cases, which has made our epidemiological investigations far more challenging.”
Primary Amoebic Meningoencephalitis is a rare but often fatal infection that affects the central nervous system, according to a Kerala government report. The infection causes rapid destruction of brain tissue, leading to severe brain swelling and, in most cases, death. PAM typically affects otherwise healthy individuals, particularly children, teenagers, and young adults.
The infection is caused by Naegleria fowleri, commonly found in warm, stagnant freshwater sources such as ponds, lakes, and poorly maintained swimming pools. The amoeba enters the body through the nose, specifically through the olfactory mucosa and cribriform plate, and travels to the brain. The report emphasises that drinking contaminated water does not cause the disease, only nasal exposure poses a risk. This places individuals who swim, dive, or bathe in freshwater bodies contaminated with the amoeba at a significantly higher risk of infection.
The document also highlights the role of climate change in increasing vulnerability. “Rising water temperatures due to global warming, combined with more people turning to water-based recreation to escape the heat, are likely to increase exposure to this pathogen,” it notes. Importantly, the infection is not contagious and does not spread from person to person.
Symptoms of PAM Infection
Primary Amoebic Meningoencephalitis is extremely difficult to diagnose and carries a very high fatality rate. Its early symptoms closely resemble those of bacterial meningitis, headache, fever, nausea, and vomiting.
According to a Kerala government document, “By the time more common causes of meningitis are ruled out and PAM is considered, it is often too late to prevent the rapid brain swelling that leads to death.”
Most patients arrive at medical facilities showing clear signs of central nervous system involvement. PAM typically occurs during warmer months and is more frequently seen in individuals with recent exposure to warm, stagnant freshwater through activities like swimming, diving, or bathing.
Symptoms can develop anywhere between one to nine days after exposure, with the disease progressing rapidly, often within hours to a couple of days. The amoeba uses the neuro-olfactory route to reach the brain, bypassing the body’s immune defenses and triggering a swift and severe course of illness.
How Is PAM treated?
Treatment for Primary Amoebic Meningoencephalitis remains extremely challenging due to the rapid progression of the disease and difficulty in early diagnosis. Nearly all known survivors over the past six decades were diagnosed before the infection reached the brain. This underscores the importance of early detection and prompt treatment.
“Early diagnosis and timely initiation of a combination of antimicrobial drugs can be lifesaving,” a Kerala government document states. Health Minister Veena George has also emphasised that “early detection is key” in improving survival chances. However, the document notes several obstacles: the rarity of PAM, its fast and aggressive course, and the challenges in diagnosing it quickly have all made it difficult to evaluate the effectiveness of various drug regimens. Ideally, treatment should include a drug, or a combination of drugs, with proven amoebicidal action and the ability to cross the blood-brain barrier.
In light of the situation, the Kerala government has urged anyone who develops symptoms consistent with PAM after exposure to stagnant freshwater to seek immediate medical attention.
Kerala reported its first PAM case in 2016. Until 2023, only eight cases had been confirmed in the state. However, there was a sharp rise in 2024, with 36 cases and nine deaths. This year, the numbers have nearly doubled: 69 confirmed cases and 19 deaths have already been reported.
In response, the state is intensifying efforts to prevent new infections. Public health advisories urge people to avoid swimming or bathing in untreated or stagnant freshwater sources like ponds and lakes. Swimmers are encouraged to use nose clips when entering freshwater, and residents are advised to properly clean and chlorinate wells and water tanks to reduce the risk of contamination.
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