# Multicenter evaluation of fast multiplex PCR for detection of pathogens in lower respiratory tract infections

## TL;DR

This study compared a fast PCR test with traditional culture methods for detecting pathogens in lung infections, showing the PCR test is faster and more accurate.

## Contribution

The study provides a multicenter validation of a rapid multiplex PCR assay for respiratory pathogens in clinical settings.

## Key findings

- The mPCR kit detected pathogens in 86.3% of specimens with high agreement with culture results.
- Multiple pathogens were identified in nearly 20% of samples using the mPCR method.
- Lower Ct values in PCR correlated strongly with culture positivity, indicating higher pathogen load.

## Abstract

This study aimed to compare the diagnostic performance between bacterial culture and a rapid multiplex PCR assay (Respiratory Pathogens Multiplex Nucleic Acid Diagnostic Kit) for detecting six bacterial (Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila) and six viral targets (Influenza A/B, Respiratory syncytial virus, Adenoviruses, Human rhinovirus, Mycoplasma pneumoniae) in 728 bronchoalveolar lavage (BAL) specimens.

This multicentric observational study was conducted at six comprehensive large hospitals in Hunan Province, China (May to October 2023) and assessed performance of mPCR kit by comparison with conventional culture method.

The mPCR kit detected ≥1 pathogen in 628 specimens (positivity rate: 86.3%), demonstrating positive percentage agreement (PPA) of 84.6% (95% CI: 76.6-92.6%) and negative percentage agreement (NPA) of 96.5% (95% CI: 96.0-97.1%) versus culture. Notably, semi-quantitative concordance was 79.3% (283/357) for culture-positive specimens. Multiple pathogens were detected by mPCR in 144 samples (19.8%). Lower Ct values (≤30) correlated strongly with culture positivity.

The mPCR kit is a simple and rapid molecular test that could complement conventional culture method for improvement of diagnosis accuracy of Lower respiratory tract infections.