Naegleria fowleri is a single-celled organism discovered primarily in heat freshwater with the potential to trigger a illness that’s deadly within the overwhelming majority of instances.
The an infection that the Naegleria fowleri amoeba causes is named main amoebic meningoencephalitis (PAM) and it has fatality fee of greater than 97 p.c.
Fortunately, instances of this illness are extraordinarily uncommon in the USA and different components of the world the place the amoeba is discovered. However solely 4 individuals out of 154 recognized contaminated people within the U.S. from 1962 to 2021 have survived, Dr. Julia Haston, a medical epidemiologist with the Facilities for Illness Management and Prevention, advised Newsweek.
How Does Naegleria Fowleri Kill Individuals?
N. fowleri infects individuals when contaminated water enters the physique via the nostril, which usually happens when individuals go swimming or diving in heat our bodies of freshwater, akin to lakes and rivers.
“It travels to the mind alongside the olfactory nerve, which is a nerve connecting the nostril and the mind that controls our sense of scent,” Haston mentioned. “As soon as the amoeba reaches the mind, it begins destroying mind tissue and causes a devastating an infection known as main amoebic meningoencephalitis, which is often deadly.”
“The amoebae… destroy mind tissue by releasing poisonous molecules,” she mentioned. “The immune system tries to struggle the an infection by sending immune cells and fluid to the mind. The mix of the poisonous molecules and the immune response causes mind swelling and loss of life.”
Infections brought on by N. fowleri progress very quickly, and folks sometimes die inside only some days of changing into sick.
“The signs of a N. fowleri an infection are just like these of bacterial meningitis, so typically it’s not identified initially,” Haston mentioned. “There isn’t a remedy that has been confirmed to forestall loss of life; nonetheless, remedy choices can be found.”
The truth that N. fowleri can feed on mind tissue within the human physique has led to it being dubbed a “brain-eating” amoeba.
“Naegleria fowleri is often a free-living amoeba that feeds on micro organism and thrives in heat pure environments,” Dr. Bobbi Pritt, director of the scientific parasitology laboratory on the Mayo Clinic, advised Newsweek. “Sadly, it will probably additionally feed on mind tissue and is completely suited to outlive and multiply at human physique temperature.”
“Individuals contaminated with N. fowleri die when components of the mind that management very important features akin to respiration are destroyed. The injury is brought on by the amoebae feeding on mind tissue, in addition to from mind swelling related to an infection. Because the mind swells, it’s compelled via small openings just like the foramen magnum (the opening of the cranium to the spinal canal) which results in tissue loss of life.”
Why Is the Fatality Fee so Excessive for Naegleria fowleri Infections?
The fatality fee for N. fowleri infections may be very excessive as a result of the amoebae multiply so quickly inside the human physique and are so efficient at destroying mind tissue.
“The contaminated particular person has no particular, pre-existing protection strategies to the amoebae, so they’re unable to include the an infection on their very own,” Pritt mentioned. “Within the uncommon cases the place individuals survived, it was as a result of the an infection was identified early on, earlier than a lot injury was achieved, they usually had been handled very aggressively.”
“The survivors reported thus far in the USA had been handled with a number of medication to kill the amoebae, and with therapeutic hypothermia (cooling the physique’s temperature beneath regular ranges) to cut back mind swelling.”
What Are the Signs of a Naegleria fowleri An infection?
The preliminary signs of PAM, which seem anyplace between one and 9 days after an infection, embrace a stiff neck, confusion, lack of consideration to the encompassing setting, lack of stability, seizures and hallucinations.
After the looks of signs, the illness progresses quickly, often leading to loss of life anyplace between one and 12 days after onset.