COVID-19: CDC guidance for expanded screening testing to reduce silent spread of SARS-CoV-2. Among 299 real-time RT-PCR positive results, 142 (47.5%) were false-negative BinaxNOW antigen test results (63 in specimens from symptomatic persons and 79 in specimens from asymptomatic persons). for symptomatic persons or for persons with a known COVID-19 exposure) a negative antigen test result should be confirmed by NAAT. Terms of Use| There were 903408 rapid antigen tests conducted for 537 workplaces, with 1322 positive results (0.15%), of which 1103 had PCR information. These persons ranged in age from 18 to 92 years (median52 years). The Abbott BinaxNOW rapid antigen test is cheaper and faster than real-time reverse transcription PCR (rRT-PCR) for detecting severe acute respiratory syndrome coronavirus 2. BinaxNOW test results were interpreted immediately at the 15-minute read time by the racetrack physician in accordance with the test kit instructions, along with the updated scoring criteria described by Pilarowski et al. All of the false-positive test results from these 2 workplaces were drawn from a single batch of Abbotts Panbio COVID-19 Ag Rapid Test Device. In dual-positive pairs, the median time between rRT-PCR specimen collection date and results reported date was 4 days (range 16 days). All specimen collection and antigen testing occurred outdoors in the parking lot of the facility. No staff were permitted to return to onsite residence until the outbreak had ended. T, Fukumori This COVID-19 test is designed to detect an active infection with or without symptoms and, according to Abbott, it can detect multiple strains, including the delta variant. Finally, many factors might limit the ability to culture virus from a specimen, and the inability to detect culturable virus should not be interpreted to mean that a person is not infectious. Concerns have been raised whether rapid antigen tests for SARS-CoV-2 can result in false-positive test results1,2 and undermine pandemic management for COVID-19. Participants were asked whether they had each sign or symptom from a list based on Council for State and Territorial Epidemiologists clinical criteria for COVID-19 that included fever, cough, shortness of breath, fatigue, sore throat, headache, muscle aches, chills, nasal congestion, difficulty breathing, diarrhea, nausea, vomiting, abdominal pain, rigors, loss of taste, and loss of smell. ** Based on one or more symptoms. Exposure was defined as close contact (within 6 ft for 15 min) in the 14 days before the day of testing with a person with diagnosed COVID-19. Received positive real-time RT-PCR or antigen test result. Dr Agrawal reported serving on the boards of Genpact and Sanctuary. Testing among symptomatic participants indicated the following for the BinaxNOW antigen test (with real-time RT-PCR as the standard): sensitivity, 64.2%; specificity, 100%; PPV, 100%; and NPV, 91.2% (Table 2); among asymptomatic persons, sensitivity was 35.8%; specificity, 99.8%; PPV, 91.7%; and NPV, 96.9%. The FDA first gave emergency use authorization for Abbott Labs ' rapid COVID-19 test for at-home, over-the-counter and non-prescription use in March. False-Positive Results in Rapid Antigen Tests for SARS-CoV-2 | Clinical Pharmacy and Pharmacology | JAMA | JAMA Network This study examines the incidence of false-positive results in a sample of rapid antigen tests used to serially screen asymptomatic workers throughout Canada. Numerous biological (e.g., individual antibody status and specific sequence of the virus) and environmental (e.g., storage conditions and number of freeze-thaw cycles) variables can affect the sensitivity and outcome of viral culture. The overall rate of false-positive results among the total rapid antigen test screens for SARS-CoV-2 was very low, consistent with other, smaller studies.3 The cluster of false-positive results from 1 batch was likely the result of manufacturing issues rather than implementation. Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. Overflow into the wells of true negative samples that are positioned near positive samples in the assay tray could produce false positive results. Epub December 26, 2020. Among symptomatic participants, 113 (13.7%) received a positive BinaxNOW antigen test result, and 176 (21.3%) received a positive real-time RT-PCR test result. For details, see FDA Actions below. Atlanta, GA: US Department of Health and Human Services, CDC; 2020. remind us that it is important to ensure that tests are stored and used within the temperature range specified by the manufacturer. mmwrq@cdc.gov. W, Fierce Biotech. A rapid COVID-19 test swab being processed. Positive Predictive Value depends upon prevalence of disease in community, Role of Rapid Antigen Detection Test (RADT) for Detection of SARS Cov-2 Variants. When the pretest probability for receiving positive test results for SARS-CoV-2 is elevated (e.g., in symptomatic persons or in persons with a known COVID-19 exposure), a negative antigen test result should be confirmed by NAAT (1). even in this symptomatic group, the false negative rate is less than 1 out of 50 negative tests. Viral replication in these specimens was defined as a decrease in Ct over the culture period. Compared with real-time RT-PCR testing, the BinaxNOW antigen test had a sensitivity of 64.2% for specimens from symptomatic persons and 35.8% for specimens from asymptomatic persons, with near 100% specificity in specimens from both groups. Ford previously said launching the platform with the, Curative is among the companies to adopt the platform. Abbott's rapid COVID-19 test isn't the only point-of-care test to receive FDA authorization during the pandemic, but Trump has touted it the most by far, hailing the speed at which results can be . It is incorrect to refer to all positive rapid antigen test screens in which a PCR test, taken at about the same time, was negative, as "false positive" results. Where is the Innovation in Sterilization? Rapid antigen tests can be an important tool for screening because of their quick turnaround time, lower requirement for resources, high specificity, and high PPV in settings of high pretest probability (e.g., providing testing to symptomatic persons, to persons with a known COVID-19 exposure, or where community transmission is high). Despite the need for research on this topic, information on the performance of BinaxNOW in the setting of nonhealthcare workplace outbreaks is lacking. . Epub June 29, 2020. Abbreviations: CI=confidence interval; COVID-19=coronavirus disease 2019; NPV=negative predictive value; PPV=positive predictive value. Critical revision of the manuscript for important intellectual content: Goldfarb, Agrawal, Sennik, Stein, Rosella. However, some quarantined employees were permitted to return to work if they were needed to perform duties related to essential care of the horses. Of 100 specimens with cycle threshold <30, a total of 51 resulted in positive virus isolation; 45 (88.2%) of those were BinaxNOW-positive. The PCR tests identified an additional 14 students who were positive for COVID-19; they were moved to isolation. part 46, 21 C.F.R. Results from real-time RT-PCR and the BinaxNOW antigen test were compared to evaluate sensitivity, specificity, negative predictive value (NPV), and PPV. Chief Medical and Chief Science Officer for Angstrom Bio, Inc, a company engaged in COVID testing. Our comparison supports immediate isolation for BinaxNOW-positive persons and confirmatory testing for negative persons. CEO Robert Ford picked out the rollout of the analyzer as a driver of growth in Abbott's underlying diagnostics business in July. Another false-positive problem for a SARS-CoV-2 antigen test in Japan. Limitations of the study include the convenience sample of workplaces and that reporting of PCR confirmatory results and identification of lot number was not compulsory. Our other rapid COVID-19 test is the ID NOW system, a molecular point-of-care test the size of a toaster that's designed to deliver results in 13 minutes or less. Funding/Support: The CDL RSC was founded with financial support from 12 corporations: Air Canada, CPP Investments, Genpact, Loblaw Companies Limited, Magna, MDA, Maple Leafs Sports & Entertainment Partnership, Nutrien, Rogers, Scotiabank, Shoppers Drug Mart, and Suncor and received funding from the Safe Restart Agreement from the Government of Canada (Health Canada). FDA made that point in its alert, explaining how the false positive rate for a test with 98% specificity goes from 20% in a population with 10% prevalence to 96% in a population with 0.1% prevalence. A questionnaire capturing demographic information and current and past14-day symptoms was administered to all participants. A total of 342 different staff participated in testing rounds 1 through 6. Symptoms were reported by 11 different persons at the time of testing, which accounted for 11/769 (1.4%) of collected paired specimens. Update: COVID-19 among workers in meat and poultry processing facilitiesUnited States, AprilMay 2020. The .gov means its official.Federal government websites often end in .gov or .mil. Cells were monitored for cytopathic effect. Previous studies of BinaxNOW compared with rRT-PCR have demonstrated a high negative percent agreement (NPA) (99.4%100%) but variable positive percent agreement (PPA) (52.5%89.0%). Y, Performance and implementation evaluation of the Abbott BinaxNOW rapid antigen test in a high-throughput drive-through community testing site in Massachusetts. Including testing performed in round 0 and results reported by outside laboratories from staff seeking testing on their own, the cumulative incidence over the course of the outbreak in the entire staff was 62.3% (351/563). part 56; 42 U.S.C. The authors missed the opportunity to mention how this standard practice could have prevented this supposed occurrence of false positives. [Skip to Navigation] Evaluation of Abbott BinaxNOW rapid antigen test for SARS-CoV-2 infection at two community-based testing sitesPima County, Arizona, November 317, 2020. How about false negatives? Real-time RT-PCRpositive specimens with Ct <30 were also cultured for SARS-CoV-2 at CDPH in a Biosafety Level 3 laboratory. clinical laboratory staff and healthcare providers about the risk of false positive results with two Abbott Laboratories tests for COVID-19. Results of BinaxNOW testing were available the same day, which enabled more rapid identification of infected workers for isolation than reliance on rRT-PCR alone. In this instance, it is recommended to . doi:10.1001/jama.2021.24355. Abbott's BinaxNOW antigen test is one of two types of diagnostic tests. Abbott's status as a supplier to clinical laboratories means the problem will affect multiple other organizations. In previous statements to news outlets, Abbott has said that the false positive rate of the test was only 0.02%. Sect. Furthermore, each round of testing was intended to capture all staff who had not yet tested positive; however, participant attrition occurred between testing rounds. A few weeks later, cases started spiking again, as the highly infectious Delta variant spread. that detection of these variants is missed by RTPCR targeting S/ORF genes, making RTPCR and less accurate reference standard. This study investigated the incidence of false-positive results in a large sample of rapid antigen tests used to serially screen asymptomatic workers throughout Canada. So how common are false positive rapid COVID-19 tests? The FDA first gave emergency use authorization for Abbott Labs ' rapid COVID-19 test for at-home, over-the-counter and non-prescription use in March. Customers can self-administer the. Before sharing sensitive information, make sure you're on a federal government site. Asymptomatic employees were screened twice weekly. Third, some missing data limit this analysis from encompassing the entire outbreak. CDC twenty four seven. The FDA urged clinical laboratories and healthcare providers to retest any patients who have recently received a positive result from two of Abbott's PCR COVID-19 assays after identifying a. Performing BinaxNOW tests in the recommended temperature range might have improved performance. The FDA issued an Emergency Use Authorization (EUA) to permit emergency use of the Alinity m Resp-4-Plex AMP test on March 4, 2021. Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. These cookies may also be used for advertising purposes by these third parties. More than 1.8 million Abbott ID Now tests for the novel coronavirus,. Our results indicate that BinaxNOW performs better at identifying rRT-PCRpositive specimens with lower Ct (suggestive of higher viral loads) and positive viral cultures, although these factors are not precise proxies for infectiousness. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html. Let MedTech Dive's free newsletter keep you informed, straight from your inbox. When only rRT-PCR tests with Ct <30 were considered positive, BinaxNOW produced these results: PPA, 55.6% (95% CI45.2%65.6%); NPA, 100% (95% CI99.5%100%), PPV, 100.0% (95% CI93.5%100%); and NPV, 93.8% (95% CI91.8%95.5%) (Table 3). Further studies are needed to determine whether serial rapid antigen testing alone can identify infectious persons as efficiently as rRT-PCR alone or a combination of rRT-PCR and rapid antigen testing (13). Although Ct cannot be used to define viral load or infectivity of a given person, Ct is inversely related to the amount of target genetic material present in the specimen (11). We thank Lisa B. Hernandez, James Allard, Beimnet Taye, the California Department of Public Health Viral and Rickettsial Disease Laboratory staff, and the racetrack staff described in this report. A first swab specimen was used for onsite BinaxNOW testing; a second swab specimen was placed in viral transport medium and chilled on ice packs before transport to the CDPH laboratory for rRT-PCR testing 2472 hours after collection.