Environmental isolation of pathogenic Naegleria

Only recently has it been recognized that one genus of Naegleria can cause fatal human infections. On entry of the nasal passages of a susceptible individual, Naegleria fowleri can traverse the nasal mucosa and enter the brain via the olfactory nerve. The ensuing primary amoebic meningo encephalitis (PAME) is almost always fatal. Naegleria are one of many genera commonly found in soil and water. Consequently, it is not surprising that the distribution of fatal PAME is worldwide. Cases of the disease have been reported in the U.S., England, Australia, New Zealand, and Africa. While found in many locales, N. fowleri is generally isolated from naturally wanned water such as shallow ponds or from artificially heated water associated with swimming pools and industrial processes. Techniques for detecting and isolating the pathogen are cumbersome. Recent studies indicate that cytofluorography may be a useful tool for rapid detection and quantitation of N. fowleri. Chlorine has been effective in controlling the pathogen in swimming pools and in at least one industrial site.