Fulminant community-acquired infectious diseases: diagnostic problems.

The processes presented here do not represent an all-inclusive list of fulminant infectious diseases. Some of the more common acute, overwhelming infections of the central nervous system and lungs are covered elsewhere in this issue. We have selected less common, potentially catastrophic syndromes that might be recognized earlier if certain historical clues, physical findings, or laboratory abnormalities are appreciated. Specific and effective therapy is available for most of the diseases we have chosen. Meningitis due to Naegleria fowleri, a free-living ameba that may invade the central nervous system through the cribriform plate in persons swimming in brackish water, and hemorrhagic mediastinitis due to inhalation of Bacillus anthracis, which is acquired in occupational exposure to goat's hair, wool, or an animal with anthrax, are other examples but are lacking in proven effective therapy. Although most physicians quickly consider exotic and overwhelming infections in the severely compromised patient, fewer recognize this risk in the diabetic, cirrhotic, or healthy person with a unique occupational or travel history. During the present epidemic of AIDS, previous exposure to the HTLV-3 virus must be considered in all severely ill patients. The proper use of new diagnostic tests may permit the physician to intercede effectively if these life-threatening diseases are suspected.