Reverse transcription recombinase-aided amplification assay for H7 subtype avian influenza virus

H7 subtype avian influenza virus infection is an emerging zoonosis in some Asian countries and an important avian disease worldwide. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse transcription recombinase-aided amplification assay for the detection of H7 subtype avian influenza virus. Assays were performed at a single temperature (39°C) and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus, which are the other main respiratory viruses affecting birds. The analytical sensitivity was 102 RNA copies per reaction at a 95% probability level according to probit regression analysis, with 100% specificity. Compared with published reverse transcription quantitative real-time polymerase chain reaction assays, the κ value of the reverse transcription recombinase-aided amplification assay in 342 avian clinical samples was 0.988 (p < .001). The sensitivity for avian clinical sample detection was 100% (95%CI, 90.40%-100%) and the specificity was 99.96% (95%CI, 97.83%-99.98%). These results indicated that our reverse transcription recombinase-aided amplification assay may be a valuable tool for detecting avian influenza H7 subtype virus.