The Killer Amoeba

Naegleria fowleri, a deadly amoeba, thrives in warm water and is a predator of bacteria. It can transform into different stages to survive but is most dangerous in its trophozoite stage. This microbe is commonly found in freshwater sources but can also survive in improperly treated water bodies like swimming pools.

During the summer, when people are more likely to come into contact with contaminated water, the risk of encountering Naegleria fowleri increases. While most individuals have antibodies against the amoeba and can ingest it without harm, the real danger arises when water containing the amoeba enters the nasal passages. In such cases, the amoeba can travel to the brain and cause severe infection.

However, Naegleria fowleri is unfazed by these obstacles and calmly surveys the surroundings. If unlucky, the tiny organism stumbles upon something that piques its interest: Nerve cells. Your nose contains a complex network of olfactory nerve cells that detect molecules from the environment and send the information to your olfactory bulb, the brain's smell centre. To perform their function, these cells communicate by releasing different messenger chemicals and recognising them through specific receptors. One of the most crucial chemicals is acetylcholine. Unfortunately, Naegleria fowleri possesses receptors that can detect acetylcholine, and it is irresistibly drawn to them, much like moths are attracted to light. As your olfactory nerve cells use acetylcholine to communicate with the brain, Naegleria fowleri infiltrates your tissue, seemingly following the chemical signals upstream.

Neutrophils, aggressive defenders, begin to attack the amoebae. Individually, they stand no chance against the large and robust invaders, accustomed to facing formidable foes. The defenders swarm the intruders and eliminate them by releasing chemicals that create holes in them or by physically tearing them apart and consuming them. However, the Naegleria fowleri train continues on its path, despite the Neutrophil attacks slowing them down, as they persist in following the olfactory nerves to their ultimate destination: Your brain. This process can take anywhere from one to nine days, during which you are unlikely to notice any symptoms. Once the amoebae reach the olfactory bulb, the gateway to your brain and the centre of smell, your brain cells become helpless victims, releasing the enticing acetylcholine. Naegleria fowleri then launches an assault, releasing varieties of attack molecules, some of which are essentially little bombs.

Despite the valiant efforts of the Neutrophils, Naegleria fowleri continues its journey and eventually reaches your brain, initiating a massacre. This onslaught of attack molecules wreaks havoc, causing severe damage. The consequences of this invasion can be devastating.

The brain is severely affected by the rapid spread of the battle, leading to serious symptoms such as confusion, inability to concentrate, fatigue, seizures, and hallucinations. The brain swells up but cannot expand due to the surrounding bones, which compresses and disables the brainstem, ultimately leading to death within a week for up to 97% of infected patients.

Infections by Naegleria fowleri are often recognised too late, leaving little to no options for treatment. The amoeba can overcome the immune system effectively, and there are currently no effective treatments available. However, the risk of infection is low, with only a few hundred cases reported in the last few decades.

While Naegleria fowleri is extremely deadly, the risk of infection is minimal. The amoeba needs to be flushed high up the nose and overcome the body's defences, making it a rare occurrence. Despite this, there is still much to learn about the amoeba, and until an effective treatment is found, it will continue to pose a vague and horrifying threat.

To prevent infection by Naegleria fowleri, it is important to avoid diving or swimming in warm, untreated water sources where the amoeba may be present. By taking precautions and being aware of the risks, individuals can protect themselves from this deadly microbe and enjoy a safe summer day by the water.