Efficacy of stool multiplex polymerase chain reaction assay in adult patients with acute infectious diarrhea

BACKGROUND Recently, stool multiplex polymerase chain reaction (PCR) tests have been developed for identifying diarrhea-causing bacterial pathogens. Furthermore, fecal calprotectin is a well-known effective marker for intestinal mucosal inflammation. AIM To evaluate the efficacy of stool multiplex PCR and fecal calprotectin in acute infectious diarrhea. METHODS Overall, 400 patients with acute infectious diarrhea were enrolled from Kangdong Sacred Heart Hospital (January 2016 to December 2018). Multiplex PCR detected 7 enteropathogenic bacteria includingSalmonella,Campylobacter,Shigella,Escherichia coliO157:H7,Aeromonas,Vibrio, andClostridium difficile. We reviewed clinical and laboratory findings using stool multiplex PCR. RESULTS Stool multiplex PCR test detected considerably more bacterial pathogens than stool culture (49.2%vs5.2%), withCampylobacteras the most common pathogen (54%). Patients with positive stool PCR showed elevated fecal calprotectin expression compared to patients with negative stool PCR (1124.5 +/- 816.9 mg/kgvs609 +/- 713.2 mg/kg,P =0.001). C-reactive protein (OR = 1.01, 95%CI: 1.001-1.027,P =0.034) and sigmoidoscopy-detected colitis (OR = 4.76, 95%CI: 1.101-20.551,P =0.037) were independent factors in stool PCR-based detection of bacterial pathogens. Sensitivity and specificity of calprotectin were evaluated to be 70.5% and 60.9%, respectively (adjusted cut-off value = 388 mg/kg). CONCLUSION Stool multiplex PCR test has increased sensitivity in detecting pathogens than conventional culture, and it is correlated with calprotectin expression. Stool multiplex PCR and calprotectin may be effective in predicting clinical severity of infectious diarrhea.