Diagnosis of gastrointestinal infections: comparison between traditional microbiology and a commercial syndromic molecular-based panel.

Abstract

Traditional diagnosis of infectious gastroenteritis is based on culture, microscopy and antigen detection. The development of gastrointestinal syndromic panels based on molecular techniques have allowed rapid and simultaneous identification of multiple pathogens. The objective was to evaluate the implementation of Allplex™ Gastrointestinal Panel Assays (AGPA): Allplex™ GI-Virus, Allplex™ GI-Bacteria (I) and Allplex™ GI-Parasite by comparing with traditional diagnosis. A retrospective comparative study was conducted at Hospital Universitario La Paz, between the first year of implementation of the AGPA (April 1, 2018 to March 31, 2019) and the results obtained during the previous year with traditional methods (April 1, 2017 to March 31, 2018). With the implementation of AGPA we obtained an increase in the detection of rotavirus and adenovirus, being statistically significant for rotavirus ([CI95%:3.60-6.79]; P<0.05) and an increase in the positivity rates of all the bacteria tested, with the exception of Salmonella spp. ([CI95%:3.60-6.79]; P<0.05). Comparing the bacteria recovered by culture, we obtained an increase in the case of Shigella spp. cultivation during the AGPA period. Regarding protozoa, we achieved a significant increase in the positivity rates for Cryptosporidium spp. ([CI95%:1.98-3.01] P<0.05), Giardia intestinalis ([CI95%:3.94-5.25]; P<0.05) and Blastocystis spp. ([CI95%:9.44-11.36]; P<0.05). There was an improvement in report turnaround time when comparing molecular diagnosis to bacterial culture and concentration plus microscopy for parasites; but not compared with antigen detection. The molecular diagnosis approach with AGPA were more sensitive and had a faster turnaround time for some targets, and in our setting, enabled an increased diagnostic capacity for viruses and protozoa.