A systematic review of the sensitivity and specificity of lateral flow devices in the detection of SARS-CoV-2.

BACKGROUND: Lateral flow devices (LFDs) are viral antigen tests for the detection of SARS-CoV-2 that produce a rapid result, are inexpensive and easy to operate. They have been advocated for use by the World Health Organisation to help control outbreaks and break the chain of transmission of COVID-19 infections. There are now several studies assessing their accuracy but as yet no systematic review. Our aims were to assess the sensitivity and specificity of LFDs in a systematic review and summarise the sensitivity and specificity of these tests. METHODS: A targeted search of Pubmed and Medxriv, using PRISMA principles, was conducted identifying clinical studies assessing the sensitivity and specificity of LFDs as their primary outcome compared to reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of SARS-CoV-2. Based on extracted data sensitivity and specificity was calculated for each study. Data was pooled based on manufacturer of LFD and split based on operator (self-swab or by trained professional) and sensitivity and specificity data were calculated. RESULTS: Twenty-four papers were identified involving over 26,000 test results. Sensitivity from individual studies ranged from 37.7% (95% CI 30.6-45.5) to 99.2% (95% CI 95.5-99.9) and specificity from 92.4% (95% CI 87.5-95.5) to 100.0% (95% CI 99.7-100.0). Operation of the test by a trained professional or by the test subject with self-swabbing produced comparable results. CONCLUSIONS: This systematic review identified that the performance of lateral flow devices is heterogeneous and dependent on the manufacturer. Some perform with high specificity but a great range of sensitivities were shown (38.32-99.19%). Test performance does not appear dependent on the operator. Potentially, LFDs could support the scaling up of mass testing to aid track and trace methodology and break the chain of transmission of COVID-19 with the additional benefit of providing individuals with the results in a much shorter time frame.

Weekly population testing could stop this pandemic and prevent the next.

The rapid spread of the SARS-COV-2 delta variant in the UK despite high vaccination coverage will inevitably accelerate when social restrictions end unless testing and contact tracing become much more effective. To minimize further social and economic damage, the effect on R of introducing weekly population testing as social restrictions are relaxed should be evaluated. The large increase in testing capacity required can be achieved with self-taken saliva samples analysed by RT-LAMP in local testing facilities. The costs and effectiveness can be evaluated in whole-city demonstration studies. A local population register in each city or district is essential to issue weekly invitations, manage sample collection, monitor results and achieve rapid notification of households and other contacts when a test is positive. In the UK, weekly test invitations should be managed, like vaccination invitations, by the NHS, with social and financial support for quarantined households to make self-isolation acceptable. A framework for effective population testing that had been established and evaluated during this pandemic could be rapidly reinstated to suppress the next pandemic while vaccines for a new and perhaps more deadly virus are developed and rolled out.

A scoping review of the experience of implementing population testing for SARS-CoV-2.

OBJECTIVES: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - also known as the coronavirus disease (COVID-19) - pandemic has led to the swift introduction of population testing programmes in many countries across the world, using testing modalities such as drive-through, walk-through, mobile and home visiting programmes. Here, we provide an overview of the literature describing the experience of implementing population testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). STUDY DESIGN: Scoping review. METHODS: We conducted a scoping review using Embase, Medline and the Cochrane library in addition to a grey literature search. We identified indicators relevant to process, quality and resource outcomes related to each testing modality. RESULTS: In total, 2999 titles were identified from the academic literature and the grey literature search, of which 22 were relevant. Most studies were from the USA and the Republic of Korea. Drive-through testing centres were the most common testing modality evaluated and these provided a rapid method of testing whilst minimising resource use. CONCLUSIONS: The evidence base for population testing lacks high quality studies, however, the literature provides evaluations of the advantages and limitations of different testing modalities. There is a need for robust evidence in this area to ensure that testing is deployed in a safe and effective manner in response to the COVID-19 pandemic.