DIAGNOSTIC-TESTS IN GASTROINTESTINAL INFECTIONS

New or improved test procedures for the diagnosis of infectious diarrhea and gastritis are reviewed. Emphasis is placed on new rapid tests that can be incorporated into the work flow of the clinical laboratory, as well as a description of promising new technologies. Of particular interest are reports of new or improved nucleic acid probes, which can detect and identify Campylobacter species, various classes of diarrheagenic Escherichia coli, Salmonellae, and Vibrio cholerae. New polymerase chain reaction (PCR)-based techniques for the detection of toxin A-producing Clostridium difficile, shiga-like toxin-producing Escherichia coli, and Yersinia species are also reviewed, along with reports of nucleic acid amplification of genetic sequences from rotavirus, Shigellae, and invasive E. coli directly from fecal specimens. The levels of sensitivity and specificity of these molecular methods of rapid detection and identification of enteric pathogens are also discussed.