Amidst the rising COVID-19 cases, the first reported case of brain-eating amoeba in South Korea has left everyone disturbed. A person in his 50s died because of the amoeba infection, which is known to be very rare. The Korea Disease Control and Prevention Agency (KDCA) has asked people to take care and avoid freshwater bodies in places with warm climates. Sounds alarming? It is. Let's look up some more facts about this dangerous micro-organism and learn how to avoid it.
What is the brain-eating amoeba?
Its scientific name is Naegleria fowleri. For those acquainted with the biological classification, this micro-organism belongs to the phylum Percolozoa, which is technically not classified as a true amoeba, but a shapeshifting amoeboflagellate excavates (a unicellular Eukaryote with flagellates). It is typically found in warm freshwater bodies such as ponds, rivers, hot springs, warm water discharge from industrial or power plants, geothermal wells and even in poorly maintained swimming pools and water heaters. It is also present in soils.
What about the disease?
Naegleria fowleri can cause a sudden and severe brain infection called naegleriasis or primary amoebic meningoencephalitis (PAM). The infection takes place when water containing the amoeba is inhaled through the nose and it reaches the brain. The micro-organism travels through the olfactory nerve tissue to the brain. Therefore, KDCA has asked people to be careful when indulging in water sports. Infection cannot be caused if the water is ingested.
Why does N. fowleri eat brains?
Actually, the amoeba eats bacteria present in the sediments deposited in freshwater bodies. Brain becomes a chance food for it. During human infections, it is attracted to the chemical that neurons (nerve cells) use to communicate. They produce two enzymes which dissolve the protein present in the neurons.
What are the symptoms?
Symptoms usually appear within five days of infection. They include fever, nausea, loss of appetite, vomiting, a stiff neck, seizures and also an altered mental state. There also may be hallucinations, drooping eyelids, blurred vision and loss of the sense of taste. In severe cases, the infection can lead to coma and death. Death usually occurs within three to seven days from the onset of the infection. Only a handful of people worldwide have been reported to survive it.
So, can the disease not be cured?
At present, there is no specific treatment available for PAM, owing to the rarity of the infection and lack of diagnostic tests. In case of suspected infections, lab tests that look for samples of the amoeba in the cerebrospinal fluid, biopsy or tissue specimens are conducted. But only very few specialised labs are there for the tests. The core antimicrobial treatment consists of the antifungal drug amphotericin B, along with azithromycin, fluconazole, rifampin, miltefosine and dexamethasone. Still, the rate of fatality is high. A key factor to effective treatment is a speedy diagnosis, which is hampered by the rarity of the infection.
How can it be avoided?
Avoiding contact with stagnant water bodies and water-related activities can help. The KDCA has asked people to stay away from water sports if they have cuts or abrasions on the skin. It is also better for people who have the habit of cleansing their noses with tap water to avoid doing it. It may be noted that the infection is not communicable.
