CLINICAL PRESENTATION

Incubation period:

Symptoms generally appear 2-7 days after N. fowleri enters the body.

Clinical course:

The disease has a rapid clinical course--the infected person usually falls into a coma and dies 3-10 days after the onset of symptoms.

Disease begins with abrupt onset of spiking fevers and a frontal lobe headache for about a day. This is followed by nausea, vomiting, and a stiff neck. About 2/3 of patients demonstrate mental impairment and irrationality. Some patients also demonstrated altered smell and taste. Other symptoms that have been observed include photophobia, seizures, and cardiac abnormalities

.

Pathology:

N. fowleri trophozites are highly phagocytic. They ingest red blood cells and brain tissue by secreting lysosomal hydrolases and phospholipases, as well as heat-stable hemolytic proteins, heat-labile cytolysin, and phospholipase A.

Autopies have revealed fluid debris of neutrophils and monocytes in the subarachnoid space and gray matter as well as heavy damage along the path of entry, notably the nasal passages and olfactory neurons.