Naegleria fowleri, a type of amoeba that lives in freshwater, is also called brain-eating amoeba or killer amoeba because infection in the human brain causes meningitis and death. What are the dangers of such a Negleria Fowler?
Most microorganisms are harmless to humans, but there are exceptions that are pathogenic to humans. Negleria fowleri is known to be able to cope with the human immune system by eating human brains and causing death. For this reason, Negleria Fowlery is also called the murder amoeba.
Negleria fowleri is only 10 to 35 micrometers in size. Growing by preying on cells and other microorganisms, Negleria fowleri inhabits fresh water such as lakes, rivers, and hot springs. Sometimes they breed in places that are close to humans, such as water pipes, swimming pools, and fountains.
It is easy to encounter summers in swimming pools and lakes, as the Negleria foulery breeds more easily in warmer waters. It is difficult for humans to completely avoid contact with Negleria fowleri. In warmer regions, millions of people are in regular contact, and the majority are thought to have antibodies.
Basically, swallowing water containing negleria fowleri does not cause any major problems. However, if you swim in water contaminated with negleria foulery, or if water gets into your nose, there is a risk that it can become fatal. Although the human body has an immune system that excludes pathogens, Negleria fowleri copes well with the immune system. While Negleria fowleri’s mere nasal sensitivity is not a big deal, it is dangerous if it gets to the olfactory nerve cells in the nasal cavity. Olfactory neurons capture molecules that enter the nasal cavity and transmit the information to the olfactory bulb, which processes olfactory information in the brain.
Neurons release various neurotransmitters to transmit signals, and specific receptors recognize these substances and exchange information. One of the most important neurotransmitters is acetylcholine. Negleria fowleri has acetylcholine receptors, so it is attracted to the acetylcholine released by the olfactory nerve cells and penetrates into the tissue.
Of course, neutrophils, a type of white blood cell, try to kill Negleria fowleri that has infiltrated the tissue. Some are killed by neutrophils, but when a large amount of Negleria fowler invades, the final destination, the olfactory bulb, negleria fowleri, reaches the human brain. This process takes about 1 to 9 days, during which there are no subjective symptoms in humans.
However, the arrival of negleria fowleri in the olfactory bulb causes a variety of symptoms. Negleria fowleri releases molecules that attack the cells and begins to eat the shattered cells. If it grows in the brain as it is, it becomes a creature with 10 or more mouth-like suckers. In this state, it is said that the living cells are eaten as they are. Then, not only neutrophils, but also eosinophil granulocytes and microglia invade the brain tissue for a response and a large-scale battle takes place.
The problem is that immune cells do not fight carefully in consideration of the human body, and the fight also damages brain tissue. This is like burning a forest to kill a wolf in the forest. In addition, Negleria fowleri is excellent at passing through immune system attacks, and although normal pathogens are less active in high temperature conditions, they are ineffective against Negleria fowleri, which originally reproduces in high temperature conditions.
In the meantime, Negleria Fowleri continues to damage the brain, and when immune cells become inflamed, a lot of fluid flows into the brain. Negleria Fowleri causes subjective symptoms in a person who has entered the brain. It begins with headache, fever, and nausea, and develops into symptoms such as confusion, lack of concentration, seizures, and hallucinations. In addition, the expansion of the brain is inhibited by the skull, which expands to a certain extent, and as a result, the brain stem, which controls breathing and the like, is compressed.
It is said that many patients die within a week of infection with negleria fowleri due to these symptoms. The fatality rate is said to reach 97%. In most cases, when the patient becomes aware of the symptoms, it is late and there is no effective treatment.
It is also unclear how the freshwater Negleria fowleri copes well with the human immune system. How much should humans be wary of such a negleria foulery? Actually, you don’t need to worry that much. Negleria fowleri can certainly cause fatal pathology, but infections are fairly rare, with only 381 cases since 1937. Considering that 263,000 people worldwide drowned in 2019, the chance of drowning is much higher than the chance of getting infected with negleria fowlere in fresh water. Thus, it is unlikely that Negliria fowlery would pose a significant public health threat and could be considered a deadly amoeba for the unlucky few.