New molecular approaches in the diagnosis of acute diarrhea: advantages for clinicians and researchers

PURPOSE OF REVIEW: To provide an update of the advantages of new-generation molecular diagnostics as regards acute diarrhea, and to evaluate how they can help clinicians and researchers diagnose this condition. RECENT FINDINGS: Thanks to real-time polymerase chain reaction techniques, many enteropathogens can now be identified simultaneously within hours. Most techniques are based on amplification of specific nucleotide sequences. With high-resolution melting analyses, microarrays, and metagenomic analyses, multiple genomic sequences can be evaluated in a single sample; thus, a wide range of enteropathogens can be evaluated in one run. Molecular techniques have elucidated the role of major enteropathogens such as norovirus and bocavirus and their evolving epidemiology. They have revealed novel transmission routes, also in food-borne diarrhea outbreaks, and have opened the way to new therapies and preventive measures, as well as to surveillance of emerging rotavirus strains after vaccine introduction. SUMMARY: Molecular approaches are best suited for epidemiologic purposes and for selected clinical conditions such as early identification of treatable agents in at-risk patients, rather than for cases requiring only oral rehydration. In the field of acute diarrhea, the major application of molecular techniques is the identification of novel agents of gastroenteritis and their epidemiology.