Primary Amoebic Meningoencephalitis

Primary amoebic meningoencephalitis, also known as naegleriasis, is an almost invariably fatal infection of the brain caused by the free-living protozoan Naegleria fowleri. It produces headache, fever, nausea, vomiting, a stiff neck, confusion, hallucinations and seizures, with symptoms progressing rapidly over about five days and taking on features of both meningitis and encephalitis, which is why the condition is classed as a type of meningoencephalitis. Death usually follows within one to two weeks of the first symptoms appearing.