RESUMO
IntroductionTesting is critical to controlling the COVID-19 pandemic. Antigen-detecting rapid diagnostic tests (Ag-RDTs) that can be used at the point of care have the potential to increase access to COVID-19 testing, particularly in settings with limited laboratory capacity. This systematic review synthesized literature on specific use cases and performance of Ag-RDTs for detecting SARS-CoV-2, for the first comprehensive assessment of Ag-RDT use in real-world settings. MethodsWe searched three databases (PubMed, EMBASE and medRxiv) up to 12 April 2021 for publications on Ag-RDT use for large-scale screening, irrespective of symptoms, and surveillance of COVID-19, excluding studies of only presumptive COVID-19 patients. We tabulated data on the study setting, populations, type of test, diagnostic performance and operational findings. We assessed risk of bias using QUADAS-2 and an adapted tool for prevalence studies. ResultsFrom 4313 citations, 39 studies conducted in asymptomatic and symptomatic adults were included. Study sample sizes varied from 40 to >5 million. Of 39 studies, 37 (94.9%) investigated lateral flow Ag-RDTs and two (5.1%) investigated multiplex sandwich chemiluminescent enzyme immunoassay Ag-RDTs. Six categories of testing (screening/surveillance) initiatives were identified: mass screening (n=13), targeted screening (n=11), healthcare entry testing (n=6), at-home testing (n=4), surveillance (n=4) and prevalence survey (n=1). Across studies, Ag-RDT sensitivity varied from 40% to 100%. Ag-RDTs were noted as convenient, easy-to-use and low cost, with a rapid turnaround time and high user acceptability. Risk of bias was generally low or unclear across the studies. ConclusionThis systematic review demonstrates the use of Ag-RDTs across a wide range of real-world settings for screening and surveillance of COVID-19 in both symptomatic and asymptomatic individuals. Ag-RDTs were overall found to be easy-to-use, low cost and rapid tools, when consideration is given to their implementation and interpretation. The review was funded by FIND, the global alliance for diagnostics. SUMMARYO_ST_ABSWhat is already known?C_ST_ABSO_LIAntigen-detecting rapid diagnostic tests (Ag-RDTs) have the potential to substantially improve access to timely testing for COVID-19 and are being deployed in a variety of settings around the world C_LIO_LIWhile studies have investigated the diagnostic accuracy of Ag-RDTs, less is known about how and in what settings Ag-RDTs are being used around the world and their performance in these different settings C_LI What are the new findings?O_LIAg-RDTs are being used in a diverse range of real-world settings for mass screening and surveillance of COVID-19 among symptomatic and asymptomatic individuals C_LIO_LIThe sensitivity of Ag-RDTs is variable - ranging from 40% to 100% - and in some cases low compared with RT-PCR, meaning that the value of testing with Ag-RDTs needs to be carefully evaluated for each use case taking into account factors such as the prevalence of COVID-19 in the population, the consequences of false positive or false negative results, and whether confirmatory testing of positive or negative Ag-RDT results with RT-PCR is required C_LIO_LINevertheless, Ag-RDTs are generally reported as being easy to use and low cost, with a rapid turnaround time that enables timely identification of cases and subsequent interventions to prevent onward transmission of COVID-19 C_LI What do the new findings imply?O_LIThe evidence indicates that Ag-RDTs can be effectively deployed across a broad range of settings when consideration is given to how they are implemented and interpreted C_LIO_LIThe development of more detailed, evidence-based testing policies for Ag-RDTs will be important to help countries implement effective testing programmes and make the best use of Ag-RDTs as part of the COVID-19 testing toolkit C_LI
RESUMO
OBJECTIVE@#To determine whether the OraQuick® HIV-1/2 Assay (OraSure Technologies, Inc., Bethlehem, PA, USA) in sputum is a valid tool for HIV surveillance among TB patients.@*METHODS@#A cross sectional study was carried out on sputa of patients diagnosed with tuberculosis. Sputa were tested for antibodies to HIV using OraQuick® HIV-1/2 Assay (OraSure Technologies, Inc., Bethlehem, PA, USA). The results were compared with results of serum ELISA.@*RESULTS@#Compared to serum ELISA, the OraQuick® HIV-1/2 Assay in sputum specimens reported 90% sensitivity (9/10) and 100% specificity (307/307), with a positive predictive value of 100% (95%CI: 66.37%-100.00%) and a negative predictive value of 99.68% (95%CI: 98.20%-99.99%).@*CONCLUSIONS@#This testing method may provide a useful strategy for conducting HIV surveillance in possible co-infected TB patients at peripheral centres. Since there is no investment on infrastructure, it may be possible for paramedical health professionals to carry out the test, particularly in areas with low HIV endemicity.