Evaluation of a multiplex polymerase chain reaction for the diagnosis of infectious diarrhea in intensive care unit patients in Upper Egypt.

The rapid diagnosis of infectious diarrhea is lifesaving for intensive care unit (ICU) patients. This study evaluated a commercially available multiplex polymerase chain reaction (PCR) (BioFire FilmArray) for the diagnosis of parasitic and bacterial infections in ICU patients with secretory diarrhea in comparison to other traditional methods. This cross-sectional study included 50 subjects with infectious diarrhea. Their stool samples were subjected to macroscopic and microscopic examinations, concentration techniques, permanent staining techniques, stool culture, identification of bacterial infection by the Vitek 2 Compact 15 System, and molecular diagnosis of bacterial or parasitic infections by BioFire FilmArray multiplex PCR. Parasitological examination showed that the sensitivity and specificity of BioFire FilmArray multiplex PCR in the diagnosis of Cryptosporidium oocysts were 83.33% and 100.0%, respectively compared with 100% and 92.5% in diagnosis of G. lamblia cysts. Bacteriological examination showed that the sensitivity and specificity of BioFire FilmArray multiplex PCR in the diagnosis of E. coli and salmonella were 100% and 100.0%, respectively. The BioFire FilmArray multiplex PCR gastrointestinal (GI) panel assay was more sensitive and specific in the diagnosis of bacterial infections than parasitic infections. The BioFire FilmArray multiplex PCR GI panel assay was less sensitive in the detection of Cryptosporidium oocysts than traditional methods. In conclusion, the BioFire FilmArray multiplex PCR may be useful for rapid diagnosis of ICU patients with infectious diarrhea.