RESUMEN
Surveillance screening at scale to identify people infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prior to extensive transmission is key to bringing an end to the coronavirus disease 2019 (COVID-19) pandemic, even though vaccinations have already begun. Here we describe Corona Detective, a sensitive and rapid molecular test to detect the virus, based on loop-mediated isothermal amplification, which could be applied anywhere at low cost. Critically, the method uses freeze-dried reagents, readily shipped without cold-chain dependence. The reaction detects the viral nucleocapsid gene through a sequence-specific quenched-fluorescence readout, which avoids false positives and also allows multiplex detection with an internal control cellular RNA. Corona Detective can be used in 8-tube strips to be read with a simple open-design fluorescence detector. Other methods to use and produce Corona Detective locally in a variety of formats are possible and already openly shared. Detection specificity is ensured through inclusion of positive and negative control reactions to run in parallel with the diagnostic reactions. A simple user protocol, including sample preparation, and a bioinformatics pipeline to ensure that viral variants will still be detectable with SARS-CoV-2 primer sets complete the method. Through rapid production and distribution of Corona Detective reactions, quite inexpensive at scale, daily or weekly surveillance testing of large populations, without waiting for symptoms to develop, is anticipated, in combination with vaccination campaigns, to finally control this pandemic.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , ARN Viral/genética , Transcripción Reversa , Sensibilidad y EspecificidadRESUMEN
As the second year of the COVID-19 pandemic begins, it remains clear that a massive increase in the ability to test for SARS-CoV-2 infections in a myriad of settings is critical to controlling the pandemic and to preparing for future outbreaks. The current gold standard for molecular diagnostics is the polymerase chain reaction (PCR), but the extraordinary and unmet demand for testing in a variety of environments means that both complementary and supplementary testing solutions are still needed. This review highlights the role that loop-mediated isothermal amplification (LAMP) has had in filling this global testing need, providing a faster and easier means of testing, and what it can do for future applications, pathogens, and the preparation for future outbreaks. This review describes the current state of the art for research of LAMP-based SARS-CoV-2 testing, as well as its implications for other pathogens and testing. The authors represent the global LAMP (gLAMP) Consortium, an international research collective, which has regularly met to share their experiences on LAMP deployment and best practices; sections are devoted to all aspects of LAMP testing, including preanalytic sample processing, target amplification, and amplicon detection, then the hardware and software required for deployment are discussed, and finally, a summary of the current regulatory landscape is provided. Included as well are a series of first-person accounts of LAMP method development and deployment. The final discussion section provides the reader with a distillation of the most validated testing methods and their paths to implementation. This review also aims to provide practical information and insight for a range of audiences: for a research audience, to help accelerate research through sharing of best practices; for an implementation audience, to help get testing up and running quickly; and for a public health, clinical, and policy audience, to help convey the breadth of the effect that LAMP methods have to offer.