The death of three people in the Southern parts of America in the summer of 2011, caused the spotlight to be fixed on Naegleria fowleri, the brain-eating amoeba, which was the cause of these tragic deaths.
N. fowleri is a micro-organism which can be found in lakes, rivers, hot springs and soil. It thrives in warm, fresh water and extremely hot weather and droughts make conditions even more favorable for these killers. These organisms have never been found in ocean water and no evidence suggests that it can survive there.
N. fowleri can rarely gain entry into a human host and attack the central nervous system. In the event of such an infection the victim will almost always die. The mortality rate of these infections are estimated at 98%.
Doctors M. Fowler and R. F. Carter was the first to describe the human infection caused by N. fowleri in 1965 and since then more than 144 cases of this infection have been confirmed in various countries across the globe. Further retrospective studies determined that the first case of this infection was possibly in Ireland in 1909.
N. fowleri exists naturally in three various forms or stages: Cyst, Trophozoite and Flagellate.
Infection in humans are caused when N. fowleri invades the victim’s central nervous system through the nose. The initial result of the organism’s invasion results in necrosis (the premature death of cells and living tissue) as well as hemorrhaging (the loss of blood from the circulatory system) of the olfactory bulbs. From the nose the amoeba climbs along nerve fibres into the brain after which the organism starts consuming the brain cells of the victim. It then becomes pathogenic, causing primary amoebic meningoencephalitis (PAM or PAME).
Initial symptoms of infection occurs within the first 14 days after exposure to N. fowleri. It includes changes in taste and smell, headache, fever, nausea, vomiting, and stiff neck. Other symptoms include confusion, hallucinations, lack of attention, ataxia, and seizures. After onset of the symptoms the infection advances swiftly over the next 3 – 7 days finally ending in the death of the patient.
The victims of PAM are usually healthy children or young adults who was exposed to bodies of fresh water before the onset of the infection. With survival rates remaining below 1%, there is little hope of successful medical treatment. Treatment by means of combining miconazole, sulfadiazine, and tetracycline has shown very limited success and only if the treatment is started very early in the course of the infection.
Due to the fact that most cases of this infection have only been discovered after death, the lack of timely diagnosis is the main reason for the barrier to successful treatment. The infection caused by the brain-eating amoeba killed 121 people America from 1937 to 2007 and in 2011 several individuals succumbed to this infection in Virginia, Louisiana, Florida and Kansas.
Due to the rarity of N. fowleri infections, there are currently no stringent prevention efforts or strategies. However, the terrible fatality rates have caused efforts to be made in research and the development of effective diagnostics and treatment.
What makes this rare disease even more tragic is the fact that the amoeba is not intent upon attacking humans. They are usually simply on the hunt for bacteria present in water and soil.