# Comparison of the Luminex® NxTAG® Gastrointestinal Pathogen Panel to traditional diagnostic methods for detecting diarrhoea-associated gastroenteritis

## TL;DR

This study compares a new test for gut infections to traditional methods and finds it more effective at detecting pathogens.

## Contribution

The study demonstrates the superior detection rate and accuracy of the NxTAG GPP assay over traditional diagnostic methods.

## Key findings

- NxTAG GPP detected 28.3% positive infections compared to 19.5% by traditional methods.
- The assay identified 11.1% coinfections, which traditional methods missed entirely.
- NxTAG GPP showed 97.6% sensitivity and 99.7% specificity for pathogens.

## Abstract

Introduction. Gastrointestinal infections remain a leading cause of morbidity and mortality within the UK.

Hypothesis. The Luminex® NxTAG® Gastrointestinal Pathogen Panel (NxTAG GPP) multiplex reverse transcriptase PCR assay performs equivalently to standard-of-care diagnostic approaches.

Aim. To compare the analytical performance of the NxTAG GPP assay versus routine diagnostic testing methods in a district general hospital setting.

Methodology. Gastrointestinal pathogens in 159 faecal specimens from hospital inpatients and outpatient clinics were comparatively analysed using the NxTAG GPP assay versus traditional culture, enzyme immunoassay and molecular methods.

Results. Positive results were detected in 45 out of 159 specimens (28.3%) by NxTAG GPP, which was a higher positivity rate when compared with traditional diagnostic methods which detected 31 out of 159 (19.5%) positive infections (P=0.087 by Fisher’s exact test). Infections were caused by a single organism in 40 out of 45 (88.9%) cases, but 5 out of 45 (11.1%) infections detected were due to coinfections. No coinfections were detected by traditional methods. Campylobacter Group was the most common enteropathogen detected with 15 out of 52 (28.9%) infections. Viruses caused 26.9% of infections, including 15.4% being norovirus. Overall sensitivity, specificity and accuracy for the NxTAG GPP assay were 97.6%, 99.7% and 99.5%, respectively, for enteropathogenic bacteria and viruses detected during this study. No parasites were detected during this study and were not included in comparisons.

Conclusions. The NxTAG GPP assay demonstrated high sensitivity and specificity for identifying gastrointestinal pathogens, with comparable accuracy as more resource-intensive and time-consuming standard diagnostic approaches. The NxTAG GPP has the potential to enhance patient diagnosis, reduce turnaround time and improve clinical outcomes compared to routine diagnostic methods.