Amebic brain abscess and meningoencephalis.

Infections caused by the free-living amebae remind us of the fine line that divides environmental and pathogenic microorganisms, and the number and complexity of the threats our natural defenses must cope with routinely. The comparative rarity of amebic brain infections, and their devastating consequences, demand utmost vigilance from the clinician. Although in many cases nothing can be done to save the lives of persons with these maladies, early diagnosis and prompt therapy can be effective in some cases. Much remains to be discovered about the pathogenesis, diagnosis, and effective therapy of amebic CNS infections.