Naegleria

Naegleria (formes) en

Naegleria is a genus of protozoa that is best known for its species Naegleria fowleri, commonly referred to as the "brain-eating amoeba". This free-living amoeba can cause a rare and severe infection of the brain called primary amoebic meningoencephalitis (PAM), which is usually fatal. Naegleria species are found in warm freshwater environments, such as ponds, lakes, rivers, and hot springs, as well as in soil. They can also be found in poorly maintained or chlorinated swimming pools. The amoebae thrive in high temperatures and can survive in water as hot as 45°C (113°F).

Life Cycle

The life cycle of Naegleria includes three stages: cysts, trophozoites, and flagellated forms. The trophozoite stage is the active, feeding, reproducing form, which is also responsible for causing infection in humans. When environmental conditions are unfavorable, Naegleria can form a cyst, which is a dormant and resistant stage. The flagellated form occurs when the trophozoite transforms in response to certain stimuli, such as changes in the ionic concentration of the surrounding water. However, the flagellated form is not involved in human infection.

Infection and Disease

Infection with Naegleria fowleri occurs when water containing the amoeba enters the body through the nose. This can happen during activities such as swimming, diving, or other water-related activities in freshwater sources. Once in the nose, the amoebae can migrate to the brain, where they destroy brain tissue, causing swelling and usually leading to death. Symptoms of PAM include severe headache, fever, nausea, vomiting, stiff neck, seizures, altered mental status, and coma. The disease progresses rapidly, and death usually occurs within one to two weeks after symptoms begin.

Prevention

Preventive measures against Naegleria fowleri infection include avoiding water-related activities in warm freshwater during hot weather, using nose clips or holding the nose shut while swimming, and avoiding stirring up sediment in shallow warm freshwater areas. Proper maintenance and chlorination of swimming pools, as well as avoiding the use of neti pots with tap water, are also recommended to prevent infection.

Treatment

Treatment for PAM is challenging and often ineffective, but it typically includes a combination of antimicrobial agents, such as amphotericin B, rifampicin, and fluconazole. Early diagnosis and treatment are critical for improving the chances of survival, although cases of recovery are rare.