Brain-Eating Amoeba: What You Need to Know About Symptoms, Causes, Prevention, and Treatment

A teenager who had been treated for amoebic meningoencephalitis at a private hospital tragically died in a recent case in Kozhikode, Kerala. The cause of the infection was Naegleria fowleri, known as the "brain-eating amoeba." This single-celled organism is found in warm freshwater bodies like lakes, rivers, and hot springs, as well as in soil. Although Naegleria fowleri infections are rare, they can be extremely devastating and often fatal.

What is Naegleria fowleri?

Naegleria fowleri is an amoeba that belongs to the genus Naegleria. It thrives in warm, fresh bodies of water and can survive in temperatures up to 113°F (45°C). The amoeba can exist in three forms: a cyst, a trophozoite (the feeding form), and a flagellate. It is the trophozoite form that infects humans by entering the body through the nose. From there, it travels to the brain, causing primary amoebic meningoencephalitis (PAM).

Symptoms of PAM

The symptoms of PAM usually appear within one to nine days after exposure to the amoeba. Early symptoms can be similar to those of bacterial meningitis and include:

• Severe frontal headache

• Fever

• Nausea and vomiting

• Stiff neck

As the infection progresses, symptoms become more severe and may include:

• Confusion and hallucinations

• Loss of balance

• Seizures

• Sensitivity to light (photophobia)

• Coma

Unfortunately, once the symptoms of PAM appear, the disease progresses rapidly, often leading to death within about five days.

How is Naegleria fowleri Contracted?

Naegleria fowleri infection typically occurs when contaminated water enters the nose. This can happen during activities such as swimming, diving, or any other water-related activities in warm freshwater. It is important to note that you cannot get infected by drinking contaminated water. The amoeba must travel up the nasal passages to reach the brain.

Naegleria fowleri (Brain Eating Amoeba) Prevention

Preventing Naegleria fowleri infection involves minimizing the chances of water entering the nasal passages. Here are some preventive measures:

• Avoid Warm Freshwater: Refrain from swimming or diving in warm freshwater, especially during the summer months or when water levels are low.

• Use Nose Clips: When swimming or participating in water-related activities in warm freshwater, use nose clips to prevent water from entering the nose.

• Avoid Stirring Up Sediment: Avoid stirring up the sediment in shallow, warm freshwater areas, as the amoeba is more likely to be present in the sediment.

• Properly Chlorinate Pools: Ensure that swimming pools and hot tubs are properly disinfected and maintained to prevent contamination.

Treatment

The treatment of PAM is challenging due to its rapid progression and the rarity of the infection. Prompt diagnosis and treatment are critical but often difficult. The standard treatment involves a combination of antifungal and antimicrobial medications, including amphotericin B, which is typically administered intravenously and intrathecally (directly into the spinal fluid), and miltefosine, originally developed as an anti-cancer drug, which has shown some effectiveness against Naegleria fowleri. Depending on the case, other medications such as rifampin, azithromycin, and fluconazole may be used. Despite aggressive treatment, the prognosis for PAM is often poor, with a survival rate of less than 5%.

Naegleria fowleri, though rare, is a deadly pathogen that requires awareness and preventive measures to avoid infection. Understanding the risks associated with warm freshwater bodies and taking appropriate precautions can significantly reduce the chances of contracting this devastating amoeba.

While treatment options are limited and the prognosis for PAM is grim, ongoing research and public health initiatives aim to improve outcomes and increase awareness about this "brain-eating" amoeba.