Recent headlines from Kerala in India have raised concerns about a rare infection caused by Naegleria fowleri, better known by its dramatic nickname, the “brain-eating” amoeba.
Understandably, such a name can trigger anxiety, especially in countries like Malaysia where spending time in rivers, waterfalls, hot springs and pools is a favourite pastime.
Yet, it is important to put the facts in perspective.
This infection is extremely rare and Malaysia has never recorded a single case to date.
The key is not to avoid water activities altogether, but to understand how this amoeba behaves and to take simple, sensible steps that allow us to continue enjoying our natural waters safely.
Damage to the brain
N. fowleri is a microscopic organism commonly found in warm fresh water and soil.
It can cause a severe infection of the brain known as primary amoebic meningoencephalitis (PAM), which is often fatal.
Despite the frightening nickname, the amoeba does not literally “eat” the brain.
Instead, when contaminated water enters the nose – usually during diving or jumping into fresh water – the amoeba can travel along the olfactory nerve to the brain, where it triggers inflammation and damage.
Importantly, drinking contaminated water does not pose a risk.
Infection only occurs if the amoeba-laden water enters through the nasal passages.
A rare infection
Globally, cases are very few.
To give a sense of scale, millions of people swim in lakes and rivers each year without issue, while only a handful of infections have ever been documented.
The most recent outbreak, which is currently ongoing, is in the Indian state of Kerala.
Keralan health authorities have been on high alert after confirming 69 cases and 19 deaths from PAM as of Sept 18 (2025), since the start of the year.
In the United States, which maintains detailed records of such infections, only about two to three cases are reported each year – almost always during the hottest summer months when people swim in warm fresh water.
Malaysia, with its tropical climate, certainly provides the kind of environment where N. fowleri could theoretically survive.
However, the absence of any confirmed cases so far should be reassuring.
Be aware
At the same time, awareness is useful, particularly for those who enjoy outdoor water activities.
The infection is most likely to occur when people dive or jump into untreated fresh water and water is forced up their noses.
Activities that stir up mud or sediment at the bottom of rivers or ponds also carry slightly higher risks, as the amoeba tends to live in those layers.
The symptoms of infection can be confusing because they resemble more common illnesses.
In the early stages, a person may experience fever, headache, nausea or vomiting.
Later, more serious signs such as neck stiffness, confusion, seizures or sensitivity to light may develop.
The incubation period can range from one to 12 days, and the illness progresses quickly once symptoms appear.
As these signs are also common in meningitis and other conditions, medical attention should always be sought promptly if such symptoms occur after fresh water exposure.
Practise preventive methods
That being said, prevention is far more straightforward than most people think.
There is no need to give up swimming or family trips to waterfalls.
The important thing is to be smart about where and how we enjoy water activities.
Well-maintained swimming pools with proper chlorination are safe, as the amoeba cannot survive in treated water.
Recreational lakes and rivers can also be enjoyed safely by being mindful not to dive headfirst into untreated water or stir up muddy bottoms unnecessarily.
Some people choose to keep their heads above water or use simple protective measures like nose clips when swimming in natural fresh water.
After swimming, it is always a good habit to shower with soap and treated water, both for overall hygiene and to minimise any lingering exposure.
For those who practise nasal rinsing at home, it is essential to use sterile or boiled water, rather than tap water directly.
At present, treatment options for N. fowleri infection are limited.
A few patients worldwide have survived after receiving a combination of medicines such as amphotericin B and miltefosine, sometimes alongside advanced medical measures to reduce brain swelling.
However, these are exceptional cases.
Because the disease progresses rapidly, early recognition is vital in order to start life-saving treatment as soon as possible.
However, this is often difficult to achieve in practice.
This is why public health experts emphasise prevention and awareness as the best defence.
Encouragingly, scientific research continues worldwide to improve diagnostic methods and explore potential treatments.
Enjoy with precaution
It is worth stressing again that the actual risk of contracting this infection is exceedingly low.
The term “brain-eating” amoeba may be alarming, but the reality is that cases remain isolated and uncommon.
For Malaysians, the greater health threats continue to be conditions such as dengue fever, foodborne illnesses or non- communicable diseases.
Compared to these, the likelihood of encountering N. fowleri is minuscule.
So, what should Malaysians take away from these international reports?
First, we should recognise that infection is possible, but very rare.
Second, simple precautions can further reduce this already small risk.
And finally, we should remember that our rivers, waterfalls and pools remain safe and enjoyable when treated with respect and care.
Malaysia’s natural waters are part of our heritage and culture.
Families, hikers and tourists alike should continue to explore and enjoy them.
Awareness of N. fowleri is not meant to stop us from swimming, but rather to help us make informed choices.
With sensible habits, quick attention to unusual symptoms, and confidence in the fact that no cases have been reported locally, Malaysians can continue to enjoy the cooling embrace of our streams and waterfalls without fear.
Dr Vinoth Kumarasamy is a parasitologist and lecturer at Universiti Kebangsaan Malaysia. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
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