Naegleriasis

Naegleriasis
Other names	Primary amoebic meningoencephalitis (PAM), amoebic encephalitis, naegleria infection, amoebic meningitis
Histopathology of primary amoebic meningoencephalitis due to Naegleria fowleri. Direct fluorescent antibody stain.
Pronunciation	/ˌnɛɡlərˈaɪəsɪs/
Specialty	Infectious disease
Symptoms	Fever, vomiting, stiff neck, seizures, poor coordination, confusion, death
Complications	Brain damage, death
Usual onset	1 - 12 days after exposure[1]
Duration	1 - 18 days[1]
Causes	Deep nasal inhalation of Naegleria fowleri organisms from contaminated freshwater.
Risk factors	Roughly 75% of cases infect males; most cases are children or adolescents[2]
Differential diagnosis	Bacterial or fungal meningitis[3]
Prevention	Noseclips when swimming in fresh water, or avoiding freshwater environments, and proper chlorination of swimming pools
Treatment	Miltefosine, fluconazole, amphotericin B, posaconazole, voriconazole, targeted temperature management[4][5]
Prognosis	98.5% fatality rate; some, but not all, survivors have permanent neurological damage
Frequency	Extremely rare (.7 in 100,000 humans)

Naegleriasis, also known as primary amoebic meningoencephalitis (PAM), is an almost invariably fatal infection of the brain by the free-living unicellular eukaryote Naegleria fowleri. Symptoms are meningitis-like and include headache, fever, nausea, vomiting, a stiff neck, confusion, hallucinations and seizures.^[6] Symptoms progress rapidly over around five days, and death usually results within one to two weeks of symptoms.^[6][1]

N. fowleri is typically found in warm bodies of fresh water, such as ponds, lakes, rivers and hot springs. It is found in an amoeboid, temporary flagellate stage or microbial cyst in soil, poorly maintained municipal water supplies, water heaters, near warm-water discharges of industrial plants and in poorly chlorinated or unchlorinated swimming pools. There is no evidence of it living in salt water. As the disease is rare, it is often not considered during diagnosis.^{[citation needed]}

Although infection occurs very rarely,^[1] it almost inevitably results in death.^[7][8] Of the 128 naegleriasis US cases in the half-century to 2016, only two survived.^[9]