ABSTRACT
BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 pandemic, has infected more than 179 million people worldwide. Testing of infected individuals is crucial for identification and isolation, thereby preventing further spread of the disease. Presently, Taqman™ Reverse Transcription Real Time PCR is considered gold standard, and is the most common technique used for molecular testing of COVID-19, though it requires sophisticated equipments, expertise and is also relatively expensive. OBJECTIVE: Development and optimization of an alternate molecular testing method for the diagnosis of COVID-19, through a two step Reverse Transcription Loop-mediated isothermal AMPlification (RT-LAMP). RESULTS: Primers for LAMP were carefully designed for discrimination from other closely related human pathogenic coronaviruses. Care was also taken that primer binding sites are present in conserved regions of SARS-CoV2. Our analysis shows that the primer binding sites are well conserved in all the variants of concern (VOC) and variants of interest (VOI), notified by World Health Organization (WHO). These lineages include B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.427/B.1.429, P.2, B.1.525, P.3, B.1.526 and B.1.617.1. Various DNA polymerases with strand displacement activity were evaluated and conditions were optimized for LAMP amplification and visualization. Different LAMP primer sets were also evaluated using synthetic templates as well as patient samples. CONCLUSION: In a double blind study, the RT-LAMP assay was validated on more than 150 patient samples at two different sites. The RT-LAMP assay appeared to be 89.2% accurate when compared to the Taqman™ rt-RT-PCR assay.
Subject(s)
COVID-19 Testing/methods , COVID-19/virology , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , COVID-19/diagnosis , Humans , Reverse Transcription , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Sensitivity and SpecificityABSTRACT
BACKGROUND: Telemedicine is uniquely positioned to address challenges posed to emergency departments (EDs) by the Coronavirus Disease 2019 (COVID-19) pandemic. By reducing in-person contact, it should decrease provider risk of infection and preserve personal protective equipment (PPE). OBJECTIVES: To describe and assess the early results of a novel telehealth workflow in which remote providers collaborate with in-person nursing to evaluate and discharge well-appearing, low-risk ED patients with suspected COVID-19 infection. METHODS: Retrospective chart review was completed 3 weeks after implementation. Metrics include the number of patients evaluated, number of patients discharged without in-person contact, telehealth wait time and duration, collection of testing, ED length of stay (ED-LOS), 72-h return, number of in-person health care provider contacts, and associated PPE use. RESULTS: Among 302 patients evaluated by telehealth, 153 patients were evaluated and discharged by a telehealth provider with reductions in ED-LOS, PPE use, and close contact with health care personnel. These patients had a 62.5% shorter ED-LOS compared with other Emergency Severity Index level 4 patients seen over the same time period. Telehealth use for these 153 patients saved 413 sets of PPE. We observed a 3.9% 72-h revisit rate. One patient discharged after telehealth evaluation was hospitalized on a return visit 9 days later. CONCLUSION: Telehealth can be safely and efficiently used to evaluate, treat, test, and discharge ED patients suspected to have COVID-19. This workflow reduces infection risks to health care providers, PPE use, and ED-LOS. Additionally, it allows quarantined but otherwise well clinicians to continue working.