Comparison of real-time reverse transcription loop-mediated isothermal amplification and real-time reverse transcription polymerase chain reaction for duck Tembusu virus.

Duck Tembusu virus (DTMUV) has caused huge losses to the poultry industry in China since the spring of 2010. The development of a rapid, convenient, and reliable method to diagnose this emerging duck infectious disease is critical. In the present study, a real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was compared with the real-time reverse transcription polymerase chain reaction (RT-PCR) for detection of DTMUV. The sensitivity of real-time RT-LAMP was equal to that of the real-time RT-PCR, with a detection limit of 0.01 ELD(50) (50% egg lethal dose). The specificity of the real-time RT-LAMP and real-time RT-PCR was confirmed using RNAs and DNAs extracted from related viruses which cause duck infections. The reproducibility of the real-time RT-PCR assay was better than that of the real-time RT-LAMP. Only three results from 96 tissue samples differed between the real-time RT-LAMP and this real-time RT-PCR, confirming the reliability of these methods. This study indicated that the real-time RT-LAMP is simpler, less time-consuming, and more convenient than the real-time RT-PCR. With its high sensitivity, specificity, and convenience, the real-time RT-LAMP is a practical molecular diagnostic method for rapid and quantitative detection of DTMUV infection in a resource-limited setting.