Application of MRT-qPCR for pathogen detection of lower respiratory tract infection.

OBJECTIVE:To analyze and clarify the application value of multiplex quantitative real-time PCR (MRT-PCR) assay in detecting pathogens involved in lower respiratory tract infection (LRTI), so as to realize accurate and rapid detection of respiratory pathogens. METHODS:Bronchial alveolar lavage fluid (BALF) specimens from 186 patients with LRTI collected in the Cangzhou Central Hospital from June 2020 to September 2021 were analyzed retrospectively. Pathogen detection was performed by both MRT-PCR and direct immunofluorescence assay (DFA), and the results of different inspection methods were compared. RESULTS:Among the seven pathogens detected by MRT-PCR, 140 positive specimens were identified out of the 186 patients, with the top three pathogens with the highest positive rates being influenza A virus (Flu A; 36 [19.35%]), respiratory syncytial virus (RSV; 30 [16.13%]) and human adenovirus (HAdV; 23 [12.37%]), and the pathogen with the lowest positive rate being parainfluenza virus type 3 (PIV3; 9 [4.84%]). DFA showed 110 pathogen-positive specimens, and the top three pathogens with the highest positive rates were Flu A (30 [16.13%]), HAdV (21 [11.29%]) and RSV (19 [10.22%]). The total sensitivity and accuracy of MRT-PCR assay were 93.01% and 98.69% respectively, which were statistically higher than those of 48.45% and 91.24% of DFA (P<0.05). The two inspection methods showed no significant difference in specificity (99.4% for MRT-PCR assay and 97.28% for DFA) (P>0.05). CONCLUSIONS:MRT-PCR is rapid, accurate and specific in detecting pathogens of LRTI, which significantly improves the detection rate, with reliable performance and it has high clinical application value.