Multiple-Centre Clinical Evaluation of Rapid Recombinase-Aided Amplification Assays for Five Pathogens

Abstract Background: Recombinase-aided amplification(RAA) is a new, simple, and ultrafast isothermal molecular diagnostic technique performed within 30min at 39°C–42°C.In this study, we evaluated the clinical performance of four duplex RAA kits for hepatitis B virus(HBV), human adenovirus 3(HAdV3), human adenovirus 7(HAdV7), and Bordetella pertussis and one duplex reverse-transcription RAA (RT-RAA) kit for respiratory syncytial virus (RSV).Methods: A total of 392 sera and 374 respiratory tract samples were collected from five institutions in four China regions. Each RAA kit’s sensitivity and specificity were compared with those of real-time quantitative polymerase chain reaction(qPCR),real-time quantitative reverse-transcription polymerase chain reaction(qRT-PCR), or sequencing. Results: Compared with qPCR or qRT-PCR, the sensitivities of HBV RAA,RSV RT-RAA, and B.pertussis RAA were 97.55%,96.67%, and 100%,respectively,and all of the specificities were 100%.The total coincidence rates were 97.78%(383/392,95%CI:95.63%–98.85%),97.70%(212/217, 95%CI:94.57%–99.16%), and 100%(60/60,95%CI:92.80%–100%),respectively.The Kappa values were 0.977,0.947, and 1,respectively(P<0.05).Regarding the sequencing, the sensitivities of HAdV3 RAA and HAdV7 RAA were 100% and 97.37%, respectively,and all specificities were 100%.The total coincidence rates were 100%(97/97,95%CI:91.58%–100%) and 98.97%(96/97,95%CI:94.39%–99.82%),and the Kappa values were 1 and 0.978 (P<0.05),respectively.Conclusions: With comparable clinical performance, these RAA kits are suitable assays for rapidly detecting pathogens in resource-limited laboratories.