New developments in infectious diarrhea

The past decade has produced exciting advances in our knowledge of infectious diarrhea. The list of potential enteric pathogens continues to grow with both the identification of new organisms, e.g., E. coli serotype O157:H7, and the recognition that previously characterized microorganisms, e.g., M. avium-intracellulare, can also cause gastrointestinal disease in immunosuppressed patients. Multiple investigations have led to a greater understanding of the epidemiology and clinical features of these illnesses. Application of modern biological techniques has yielded a number of diagnostic assays that are just now becoming clinically relevant. New drugs and treatment modalities for enteric infections have been developed and are now being evaluated in clinical trials. Despite these advancements, however, many questions still remain unanswered. For example, the etiology of the debilitating diarrhea in AIDS patients in whom no known intestinal pathogen can be identified remains unknown. The mechanism of diarrhea due to Cryptosporidium, Isospora, and Giardia remains elusive. And last, will new intestinal vaccines be effective in preventing diarrheal disease? Certainly, the next decade of research in enteric diseases should prove to be even more interesting than the last.