Rapid detection of COVID-19 using an isothermal amplification-based lateral flow assay

3月11日，世界卫生组织宣布由严重急性呼吸系统综合征冠状病毒2 （SARS-CoV-2）引起的高度传播和致命的冠状病毒病COVID-19为全球大流行。快速检测这种SARS-CoV-2被认为是防止其社区传播和赢得这场病毒之战的关键。公共卫生机构广泛采用的这种病毒的金标准检测方法是基于逆转录-聚合酶链反应。这种方法虽然可靠，但缺点是需要精密的仪器进行严格的热循环，需要训练有素的人员，反应时间相对较长（2-4小时）。这些都削弱了加拿大每天对大量公民进行检测的能力。为了解决这些问题，我们提出了一种基于等温扩增机制的新型检测方法——重组酶聚合酶扩增（RPA），该方法可以在持续低温（37~42摄氏度）下以更快的速度（<20分钟）扩增核酸。与侧流免疫分析法（LFI）相结合，可以在几分钟内可视化RPA的核酸扩增子，而无需其他扩增子检测仪器。我们期望这种新的RPA-LFI方法能够提供与金标准方法相当的灵敏度和特异性，同时大大缩短分析时间并简化分析程序。这种新的检测方法不仅有利于加拿大在大流行期间抗击COVID-19，而且还为在资源有限的条件下对这一公共卫生威胁进行常规监测和监测提供了一种有希望的替代方案。

The highly transmitted and lethal coronavirus disease COVID-19 caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been declared as a global pandemic by the World Health Organization (WHO) on March 11th. Rapid detection of this SARS-CoV-2 has been recommended as the key to prevent its community spread and to win this battle against the virus. The gold standard detection method for this virus widely adopted by public health agencies is based on reverse transcription-polymerase chain reaction. Although reliable, this method suffers the disadvantages of requiring sophisticated instrument for stringent thermal cycling, highly trained personnel, and relatively long reaction time (2-4 hours). These have impaired Canada to test a large population of citizens on a daily basis. To address these drawbacks, we proposed to develop a novel detection method based on an isothermal amplification mechanism, recombinase polymerase amplification (RPA), which can amplify nucleic acid at a constantly low temperature (37~42 degree celsius) in a much more rapid manner (<20 minutes). Combining with a lateral flow immunoassay (LFI), the nucleic acid amplicons of RPA can be visualized in a few minutes without the requirement of other instruments for amplicon detection. We anticipate this novel RPA-LFI method to provide comparable sensitivity and specificity as compared to the gold standard method, while substantially reduce the analytical time and simplify the analysis procedure. This novel detection method will not only benefit Canada to combat COVID-19 amid the pandemic, but also provide a promising alternative for routine surveillance and monitoring of this public health threat in resource-limited conditions.