Molecular Detection of Diarrheal Pathogens

Acute diarrhea is an extremely common illness and causes a spectrum of disease, from loose bowel movements to severe dehydration and death. Most cases of acute diarrhea, and a proportion of chronic diarrhea cases, are associated with infections or their toxins, yet current diagnostic strategies are complex, time-consuming, and generally unproductive. Uniplex assays for bacteria such as Clostridium difficile or Shiga toxin-producing Escherichia coli are quicker than culture and more sensitive than antigen-based methods, while molecular methods for viral targets have largely replaced electron microscopy or antigen detection. Commercial multiplex panels are now available for viral, bacterial, and protozoal pathogens. Panels differ by included analytes, pre-analytic requirements, processing (on demand versus batch), and instrumentation. Uniplex or limited multiplex panels may complement existing laboratory methods, whereas more comprehensive multiplex panels may replace antigen detection and culture altogether. However, culture will still be needed for epidemiologic characterization and for antimicrobial susceptibly testing.