Diagnosis of infectious diarrheal diseases.

For many years, microbiologic examination of feces was focused on the isolation of two members of the family Enterobacteriaceae--Salmonellae and Shigellae. Over the past two decades, other enteric pathogens such as the various classes of diarrheagenic E. coli, Campylobacter, Vibrio spp., Yersinia enterocolitica, and Clostridium difficile have gained prominence. A newly recognized protozoan parasite, Cryptosporidium is now known to infect both immunocompetent and immunodeficient individuals. Added to these is the growing list of viruses incriminated in diarrheal diseases and gastritis. This article provides some of the basic information needed to allow for the isolation and identification of many of the currently recognized enteric pathogens. It also provides information on some of the currently available rapid test procedures that will speed up stool specimen testing and allow for more timely reporting to the physician.