Development of a recombinase-aided amplification assay for rapid detection of human norovirus GII.4

BACKGROUND: Human noroviruses are one of the main causes of foodborne illnesses and represent a serious public health concern. Rapid and sensitive assays for human norovirus detection are undoubtedly necessary for clinical diagnosis, especially in regions without more sophisticated equipment. METHOD: The rapid reverse transcription recombinase-aided amplification (RT-RAA) is a fast, robust and isothermal nucleic acid detection method based on enzyme reaction. This method can complete the sample detection at 39 °C in 30 min. In this study, we successfully established a rapid reverse transcription recombinase-aided amplification (RT-RAA) assay for the detection of human norovirus GII.4 and applied this assay to clinical samples, as well as comparison with commercial reverse transcription real-time fluorescence quantitative PCR (RT-qPCR). RESULTS: At 95% probability, the detection sensitivity of RT-RAA was 3.425 log10 genomic copies (LGC)/reaction. Moreover, no cross-reaction was observed with other norovirus genogroups and other common foodborne viruses. Stool samples were examined by RT-RAA and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Compared of RT-qPCR, kappa values for human norovirus detection with RT-RAA were 0.894 (p < 0.001), indicating that both assays were in agreement. CONCLUSION: This RT-RAA assay provides a rapid, specific, and sensitive assay for human norovirus detection and is suitable for clinical testing.