We analyzed date of onset and symptoms using data from a clinical questionnaire. Performance of an Antigen-Based Test for Understanding the false negative rates of SARS-CoV-2 RT-PCR testing is pivotal for the management of the COVID-19 pandemic and it has implications for patient management. Chen GJ, Palmer JRB, Bartumeus F, Alba-Casals A. Infect Dis Model. Fig 3. Specificity of available antibody tests may vary by assay; it is important to check the validation data provided by the manufacturer and/or performing laboratory. Privacy Policy. -. In the sample of 1000, there will be around 50 who are currently infected. Individual test results. hbbd```b``1A$" Copyright var today=new Date(); document.write(today.getFullYear()); | Web Policies, Common types of antigen and molecular tests being developed for SARS-CoV-2. Specificity is calculated based on how many people do not have the disease. The overall sensitivity of rapid antigen detection tests versus that of RT-PCR with oral, anterior nasal, and nasopharyngeal samples was 18.18% (95% confidence interval [CI] 8.19% to 32.71%), 63.04% (95% CI 47.55% to 76.79%), and 73.33% (95% CI 58.06% to 85.4%), respectively. Methods: Epub 2023 Feb 8. f The FDA has authorized more than 300. endstream endobj 108 0 obj <. However, the reliability of the tests depends largely on the test performance and the respective sampling method. 2023 Feb 3;23(1):240. doi: 10.1186/s12889-023-15036-9. uyratmP >NhHl'SlYb@~G C,l.H8Xh/2 My|PP#ZQ ,eH/dx+ P/b::@\A &"`^X(DZDAX `CA[tv@sx$A1%S:;6k5S1=3,`gs4n;!%&e&ywaqR K |{Q~MRx/(f0 5HL Of the 370 COVID-19 diagnostic tests that the US Food and Drug Administration has authorized for emergency use in the US, there are dozens you can take at home. The viral genomic material for SARS-CoV-2 is ribonucleic acid (RNA), which remains in the body only while the virus is still replicating, even at very low levels. Emergency Use Authorizations J Mol Diagn. The QuickVue RSV Test is a dipstick immunoassay that detects respiratory syncytial virus (RSV) antigen (viral fusion protein) directly from nasopharyngeal swab, nasopharyngeal aspirate, or nasal/nasopharyngeal wash specimens for symptomatic pediatric patients (eighteen years of age and younger). National Library of Medicine Wu S, Shi X, Chen Q, Jiang Y, Zuo L, Wang L, Jiang M, Lin Y, Fang S, Peng B, Wu W, Liu H, Zhang R, Kwan PSL, Hu Q. Ann Clin Microbiol Antimicrob. Accuracy of COVID-19 rapid antigenic tests compared to RT-PCR in a student population: The StudyCov study . 2023;12(1):6. doi: 10.1186/s43088-023-00342-3. Over-the-counter COVID-19 tests make big promises. Do they deliver? Bethesda, MD 20894, Web Policies government site. The diagnostic testing field for COVID-19 is rapidly evolving, with many tests focused on diagnosing patients with active viral infections. With others, you take a sample and mail it in for results. JAMA Netw Open 3:e2012005. HHS Vulnerability Disclosure, Help April 29,;20(10):11511160. 2020 Nov 13;17(1):177. doi: 10.1186/s12985-020-01452-5. What kind of antigen and molecular tests are on the market? Room temperature (15C to 30C/59F to 86F). H\j >w%PrNReby6l*s)do@q;@. The ratio $q = (N-P)/N$ is the proportion of uninfected. endstream endobj 1777 0 obj <>stream Indirect Virus Transmission via Fomites Can Counteract Lock-Down Effectiveness. doi: 10.1021/acsinfecdis.2c00472. All rights reserved. In mid-June, Joanna Dreifus hit a pandemic . 2020 Nov 13;17(1):177. doi: 10.1186/s12985-020-01452-5. The. The site is secure. hbbd```b``kz Sensitivity was dependent upon the CT value for each sampling method. May 27;58(8):938. Sensitivity and Specificity of SARS-CoV-2 Rapid Antigen Detection Tests ]bqi"w8=8YWf8}3aK txg^+v!a{Bhk 5YliFeT?}YV-xBmN(}H)&,# o0 official website and that any information you provide is encrypted Sample Size and Duration of Study: The aim is to test 100 unique patients. Dinnes J, Deeks JJ, Adriano A, Berhane S, Davenport C, Dittrich S, Emperador D, Takwoingi Y, Cunningham J, Beese S, Dretzke J, Ferrante di Ruffano L, Harris IM, Price MJ, Taylor-Phillips S, Hooft L, Leeflang MM, Spijker R, Van den Bruel A; Cochrane COVID-19 Diagnostic Test Accuracy Group. This does not alter our adherence to PLOS ONE policies on sharing data and materials. The QuickVue At-Home OTC COVID-19 Test is intended for the qualitative detection of the nucleocapsid protein antigen from SARS-CoV-2 from SARS-CoV-2 from individuals with or without symptoms of COVID-19. $2,262.00 / Case of 10 PK. Catalog No. Quidel Corporation Disease 2019 QuickVue At-Home COVID-19 Test March 1 0Q0QQ(\&X This test is authorized for non-prescription, unobserved, home use by . Where can I go for updates and more information? Sensitivity measures how often a test correctly generates a positive result for the condition being tested. Clipboard, Search History, and several other advanced features are temporarily unavailable. The https:// ensures that you are connecting to the 6 The use of repeat RT-PCR testing as gold standard is likely to underestimate the true rate of false negatives, as not all patients in hb```MRw@( 8 G@*YPFYl&SCsw /gjVWNQ}i7S8+tG V[jnd&u|W AO(>92H ":::b ,@61@L t9J$a`f7dfcbys s;:=Wnbwg7MdH2p > miH00DYw ee 5Lk+ If you are a manufacturer or research institution that has an EUA-approved antigen or molecular test that is not yet listed, please submit your information here. endstream endobj 1776 0 obj <>stream A diagnostic accuracy study comparing RNA LAMP, direct LAMP, and rapid antigen testing from nasopharyngeal swabs. Antigen tests are designed to detect proteins from the virus that causes COVID-19, in anterior nasal swabs. The QuickVue SARS Antigen Test detects SARS-CoV-2 antigens directly from anterior nares swab specimens. QuickVue SARS Antigen Test Page 1 of 15 For use under the Emergency Use Authorization (EUA) only . FACT SHEET FOR HEALTHCARE PROVIDERS - Food and Drug Administration Fig 1. Quidel says its COVID-19 antigen test is now on par with PCR accuracy The objective of our study was to evaluate the sensitivity and specificity of rapid antigen detection tests versus those of reverse transcriptase PCR (RT-PCR) using oral, anterior nasal, and nasopharyngeal swabs. Our aim was to determine the real-life clinical sensitivity of SARS-CoV-2 RT-PCR. The QuickVue SARS Antigen Test is authorized for use on anterior nares (NS) swab specimens directly from . Dinnes J, Deeks JJ, Berhane S, Taylor M, Adriano A, Davenport C, Dittrich S, Emperador D, Takwoingi Y, Cunningham J, Beese S, Domen J, Dretzke J, Ferrante di Ruffano L, Harris IM, Price MJ, Taylor-Phillips S, Hooft L, Leeflang MM, McInnes MD, Spijker R, Van den Bruel A; Cochrane COVID-19 Diagnostic Test Accuracy Group. endstream endobj startxref Gupta-Wright A, Macleod CK, Barrett J, Filson SA, Corrah T, Parris V, Sandhu G, Harris M, Tennant R, Vaid N, Takata J, Duraisingham S, Gandy N, Chana H, Whittington A, McGregor A, Papineni P. BMJ Open. %%EOF While PCR-tests are usually considered as the gold standard to detect infection with the SARS-CoV-2 coronavirus in terms of sensitivity as well as specificity, antigen tests (Ag-Tests) offer practical advantages in terms of costs, logistics and speed [].Because Ag-Tests may play a major role in large scale testing strategies [2, 3] in populations with low prevalence, besides . Study Raises Questions About False Negatives From Quick COVID-19 Test Due to product restrictions, please Sign In to purchase or view availability for this product. Laboratory Biosafety, FDA: The QuickVue SARS Antigen Test provides accurate and reliable results in 10 minutes, allowing for COVID-19 testing of symptomatic patients within the first five days of symptoms and asymptomatic patients when tested serially. PCR; SARS-CoV-2; infectious disease; rapid antigen detection; sensitivity; specificity; swabbing; test performance. Please enable it to take advantage of the complete set of features! ea|/0`N=CTN~FR_" E&+'y+!*Q"i%z-i@C; eD2 @xyywp1HZ@ 1e`qAF^OLFl,,gr58x=S3d#J)q@xgmLc h,r 8Ag`[X 'X For information on serology (antibody) tests, visit our serology tracker or visit our report outlining the needs of a national serology strategy. The orange lines represent the DART data for each individual, the dark blue lines represent the viral RNA target N1, and the light blue lines represents the viral target N2. %PDF-1.5 % The QuickVue At-Home OTC COVID-19 Test is a lateral flow immunoassay, with results readable by eye. Would you like email updates of new search results? Sensitivity and specificity mathematically describe the accuracy of a test which reports the presence or absence of a condition. 2021 Jan 8;22(1):39. doi: 10.1186/s13063-020-04982-z. The relatively high false negative rates of SARS-CoV-2 RT-PCR testing need to be accounted for in clinical decision making, epidemiological interpretations, and when using RT-PCR as a reference for other tests. At-Home COVID-19 Test Kit Page 2 of 14 The QuickVue At-Home COVID -19 Test is intended for self-use and/or, as applicable for an adult lay user testing another person aged 8 years or older in a . Often called "rapid tests" or "home COVID tests," these rapid antigen tests rely on a. MAUDE Adverse Event Report: QUIDEL CORPORATION QUICKVUE AT-HOME OTC %%EOF The x-axis corresponds to number of days after first reported symptoms, with 0 indicating 1 day before symptoms onset. The nasopharyngeal tract likely has (1) active virus replication and (2) enough virus to be detected in test kits. Selection of the outpatient cohort presented as a flowchart. 145 0 obj <>/Filter/FlateDecode/ID[<7B25B64DC0023C44A3787FE5A23F64CA>]/Index[107 67]/Info 106 0 R/Length 158/Prev 133259/Root 108 0 R/Size 174/Type/XRef/W[1 3 1]>>stream 10.1016/j.jmoldx.2021.01.005 We rapid-tested a sample onsite and compared results with those from reverse transcription PCR and virus culture. endstream endobj startxref 2021 May 18;12(3):e00902-21. The .gov means its official. Please enable it to take advantage of the complete set of features! 9975 Summers Ridge Road, San Diego, CA 92121, USA Dr. Keklinen reports a lecture honorarium from MSD. RIDTs are not recommended for use in hospitalized patients with suspected . The duration of this study will be determined based upon the number of specimens collected daily. As the manufacturer, SD Biosensor, transitions to this new brand,. Sensitivity vs. specificity: The eternal AI debate - MedCity News J Clin Microbiol 2020. 2021. How accurate are rapid antigen tests for diagnosing COVID-19? 2021 Feb 9;11(2):e047110. In this experiment, Governor DeWine is one of 93, of whom 45 are infected, 48 not. 238 0 obj <>/Filter/FlateDecode/ID[<14C460633FC69F4E942E936439209C81>]/Index[194 73]/Info 193 0 R/Length 178/Prev 276921/Root 195 0 R/Size 267/Type/XRef/W[1 3 1]>>stream Home Immunoassays Strep QuickVue Dipstick Strep A Test The site is secure. We have compiled a list of commercial and laboratory-developed tests that have received FDA Emergency Use Authorization. Guidance for Antigen Testing for SARS-CoV-2 for Healthcare Providers doi: 10.1136/bmjopen-2020-047110. Please use the form below to provide feedback related to the content on this product. Federal government websites often end in .gov or .mil. The .gov means its official. Healthcare professionals can purchase the QuickVue SARS Antigen Test through select authorized distributors. . Disclaimer. Nasal swab is a good alternative sample for detecting SARS-CoV-2 with rapid antigen test: A meta-analysis. Xie JW, Zheng YW, Wang M, Lin Y, He Y, Lin LR. We investigated heterogeneity . `H/`LlX}&UK&_| _`t@ Specificity is compounded It may be helpful to define some terms here. When also patients that were graded as high suspicion but never tested positive were included in the denominator, the sensitivity (95% CI) was: 67.5% (62.9-71.9%) inpatients; 34.9% (31.4-38.5%) outpatients; 47.3% (44.4-50.3%) all. Antigen and Molecular Tests for COVID-19 - COVID-19 Testing Toolkit Shafie MH, Antony Dass M, Ahmad Shaberi HS, Zafarina Z. Beni Suef Univ J Basic Appl Sci. Antigens are found on the surface of the virus particle, which are also shed in patient tissues. Online ahead of print. December 2022 Rapid antigen tests offer a quick and easy way to screen for COVID-19 on your own. %PDF-1.6 % Eur Respir J 57:2004004. doi:10.1183/13993003.04004-2020. General Information - Coronavirus (COVID-19) Some of the at-home rapid antigen tests have an overall sensitivity of roughly 85 percent, which means that they are catching roughly 85 percent of people who are infected with the virus and. government site. How accurate are at-home COVID-19 tests? | wcnc.com The agency said early results suggest that antigen tests "do detect the omicron variant but may have reduced sensitivity," meaning it's possible the tests could miss an infection, known as a . The underlying prospective, diagnostic case-control-type accuracy study included 87 hospitalized and nonhospitalized participants in a positive and a negative sample cohort between 16 March and 14 May 2021 in two hospitals in Vienna. FDA says rapid Covid antigen tests may be less sensitive in detecting Rapid influenza diagnostic tests (RIDTs) detect influenza viral antigens in respiratory tract specimens. Of these, the fraction who are infected, which we can interpret as the probability that a given person who tests positive is actually one of the infected is $$ { aP \over aP + (1 - b)(N-P) } $$, We can express this formula in terms of probabilities instead of population sizes. Int J Environ Res Public Health. There was no statistically valid correlation between the semi-quantitative PCR result and the QuickVue result. Cochrane Database Syst Rev. Fisher Scientific is always working to improve our content for you. 0 If a diagnostic test correctly identified 100% of all positive results, it would be as sensitive as possible. The Diagnostic Accuracy of SARS-CoV-2 Nasal Rapid Antigen Self-Test: A Systematic Review and Meta-Analysis. The test is called the QuickVue At-Home COVID-19 Test. hb```"!6B Available from, Kucharski AJ, Klepac P, Conlan A, Kissler SM, Tang M, Fry H, et al.. This finding illustrates the reliability of tests obtained by adequate self-collected anterior nasal specimen. Of these, 95% = 180 will test positive. 1772 0 obj <> endobj A test's sensitivity is also known as the true positive rate. For antibody tests, it is the ability to identify samples where no SARS-CoV-2 antibodies are present. Submission of this form does not guarantee inclusion on the website. The sensitivity and the specifity of rapid antigen test in 2022 Dec;7(4):811-822. doi: 10.1016/j.idm.2022.11.001. 263a, that meet the requirements to perform moderate, high or waived complexity tests. Evaluation of Abbott BinaxNOW Rapid Antigen Test for SARS-CoV-2 Noninclusion in this list should not be interpreted as a judgment on the validity or legitimacy of tests. https://www.who.int/publications/i/item/overview-of-public-health-and-so WHO Overview of public health and social measures in the context of COVID-19. Sensitivity of rapid antigen testing and RT-PCR performed on nasopharyngeal swabs versus saliva samples in COVID-19 hospitalized patients: results of a prospective comparative trial (RESTART). I have read the journals policy and the authors of this manuscript have the following competing interests: Dr. Kortela reports non-financial support from MSD, outside the submitted work. Ready to use, no need for additional equipment. Additional Information - Quidel's EUA COVID-19 Products (Scroll down to the list of EUA products and enter Quidel in the search box). Molecular tests called nucleic acid amplification tests (NAAT) rely on amplification of existing genetic material in the sample. The . 2021 May 22;20(1):38. doi: 10.1186/s12941-021-00443-w. Chaimayo C, Kaewnaphan B, Tanlieng N, Athipanyasilp N, Sirijatuphat R, Chayakulkeeree M, Angkasekwinai N, Sutthent R, Puangpunngam N, Tharmviboonsri T, Pongraweewan O, Chuthapisith S, Sirivatanauksorn Y, Kantakamalakul W, Horthongkham N. Virol J. QuickVue SARS Antigen Test. Selection of the inpatient cohort. No instrument necessary. %%EOF The sensitivity (95% CI) for laboratory confirmed cases (repeat-tested patients) was 85.7% (81.5-89.1%) inpatients; 95.5% (92.2-97.5%) outpatients, 89.9% (88.2-92.1%) all. Sensitivity and specificity are measures that are critical for all diagnostic tests. H\n@b"20K DbRKXYp/J"^b?)]M>^}1]/c1u}1_kw0e>]tKZGx[xcz,ocPO:~ Available RIDTS detect and differentiate between type influenza A and B viruses, but do not specifically identify or differentiate subtypes of influenza A viruses. No refrigerator space needed. Epub 2022 Nov 17. endstream endobj 1773 0 obj <>/Metadata 142 0 R/Outlines 202 0 R/Pages 1768 0 R/StructTreeRoot 258 0 R/Type/Catalog>> endobj 1774 0 obj <>/ExtGState<>/Font<>/XObject<>>>/Rotate 0/StructParents 0/Tabs/S/Type/Page>> endobj 1775 0 obj <>stream 0 -, Jakobsen KK, Jensen JS, Todsen T, Tolsgaard MG, Kirkby N, Lippert F, Vangsted AM, Martel CHM, Klokker M, von Buchwald C. 2021. This page was last updated on March 30, 2022. Would you like email updates of new search results? *Testing is limited to laboratories certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. GK Pharmaceuticals Contract Manufacturing Operations, Primerdesign Ltd COVID-19 genesig Real-Time PCR assay, Infectious Diseases Diagnostics Laboratory (IDDL), Boston Childrens Hospital, Northwestern Diagnostic Molecular Laboratory, Understanding the Accuracy of Diagnostic and Serology Tests: Sensitivity and Specificity. Rapid SARS-CoV-2 antigen detection assay in comparison with real-time RT-PCR assay for laboratory diagnosis of COVID-19 in Thailand. At-home covid tests and omicron: What you need to know - Yahoo! News High false-negative rate limits value of rapid COVID tests for kids The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). So in this case, when the proportion of the overall population who are infected is rather small, the test is swamped by false positives. doi: 10.1002/14651858.CD013705. Careers. j=S+wE-V`~;j`E'w=YX2xx[tdQR8*Bx"y5HMeM(362-*4CmV3aM$ YE`&zVY9{t~ 0 q0 All contact information provided shall also be maintained in accordance with our Then of our 1000, 200 will be infected. 1812 0 obj <>stream COVID Test Data - Rutgers Get smart with Governing. 2022 Oct 27;19(21):14011. doi: 10.3390/ijerph192114011. General Information - Coronavirus (COVID-19) The authors declare no conflict of interest. Included and available for separate purchase, Electrophoresis, Western Blotting and ELISA, Chromatography and Mass Spectrometry Reagents, Laboratory Syringe Needles and Accessories, Lab Coats, Aprons, and Other Safety Apparel, Sharps Disposal Containers and Accessories, Classroom Laboratory Supplies and Consumables, Applied Biosystems TaqMan Assay and Arrays Search Tool, Applied Biosystems TaqMan Custom Assay Design Tools, Applied Biosystems Custom qPCR Primers and TaqMan Probes Tool, Chemical Storage and Management Resource Center. These measures are not independently validated by the Johns Hopkins Center for Health Security. 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. 1799 0 obj <>/Filter/FlateDecode/ID[<10A139E46589C743805C124A9AB3B57B><371A73E9AEDB34478DBF012D63C79AC6>]/Index[1772 41]/Info 1771 0 R/Length 126/Prev 905933/Root 1773 0 R/Size 1813/Type/XRef/W[1 3 1]>>stream -, Mannonen L, Kallio-Kokko H, Loginov R, Jskelinen A, Jokela P, Antikainen J, et al.. Overall test sensitivity was 84.9% (95% CI 79.1-89.4) and specificity was 99.5% (95% CI 98.7-99.8). 107 0 obj <> endobj The QuickVue At-Home COVID-19 Test is a type of test called an antigen test. Deckert A, Anders S, de Allegri M, Nguyen HT, Souares A, McMahon S, Boerner K, Meurer M, Herbst K, Sand M, Koeppel L, Siems T, Brugnara L, Brenner S, Burk R, Lou D, Kirrmaier D, Duan Y, Ovchinnikova S, Marx M, Krusslich HG, Knop M, Brnighausen T, Denkinger C. Trials. False-negative RT-PCR for COVID-19 and a diagnostic risk score: a retrospective cohort study among patients admitted to hospital. Subject: qv otc consumer received false positive for 1st test; went to er room & reported pcr and antibody test as negative -- tss advised of qv otc sensitivity and specificity for positives and negatives; will log feedback for review and follow-up investigation conclusion: tested 5x retained devices with negative standard. FAQ: What you need to know about the new DIY COVID-19 antigen - CNA Dive Brief: Quidel Corporation shared new data late Friday showing its COVID-19 antigen test has 96.7% sensitivity within five days of the onset of patient symptoms. A systematic review of the sensitivity and specificity of lateral flow Accessibility . That also means that the remainder of the $N-P$ uninfected people, or $(1-b)(N-P)$, will test positive (these are the false positives). COVID-19 tests and test systems used for diagnostic or screening testing, including those for antigen testing, must have received an EUA from FDA or be offered under the policies in FDA's Policy for COVID-19 Tests. Index tests were treated as inconclusive, Sensitivity of RAD tests for C T value categories and cumulated C T, Individual test results. about 48, will return positive. AMS :: Feature Column :: Does He Have It? : Sensitivity, Specificity 1735 0 obj <> endobj QuickVue At-Home COVID-19 test - NIH Director's Blog Chaimayo C, Kaewnaphan B, Tanlieng N, Athipanyasilp N, Sirijatuphat R, Chayakulkeeree M, Angkasekwinai N, Sutthent R, Puangpunngam N, Tharmviboonsri T, Pongraweewan O, Chuthapisith S, Sirivatanauksorn Y, Kantakamalakul W, Horthongkham N. Virol J. Among 871 paired specimens from asymptomatic participants, 21 (2.4%) were antigen-positive and 17 (2.0%) were real-time RT-PCR-positive. 2022 Nov 18;19(1):191. doi: 10.1186/s12985-022-01922-y. hb```f``tAX,- Sensitivity Specificity COVID-19 At-Home Test SD Biosensor, Inc. lateral flow immunoassay ADVIA Centaur SARS-CoV-2 Antigen (CoV2Ag) Siemens Healthcare Diagnostics, Inc. . For the QuickVue rapid test the sensitivity was 8.5% (4.8-13.7%, 95% CI) and specificity was 99.2% (95.6-100%, 95% CI). Quidel QuickVue SARS Antigen Test Kit 25/Kit - Fisher Sci 2023 Feb 3:acsinfecdis.2c00472. and transmitted securely. 2021;23(4):407416. doi:10.1001/jamanetworkopen.2020.12005. Modeling the impact of surveillance activities combined with physical distancing interventions on COVID-19 epidemics at a local level. endstream endobj 1778 0 obj <>stream How do molecular tests detect SARS-CoV-2? endstream endobj startxref How Accurate Are COVID-19 Tests? Many Factors Can Affect Sensitivity There will still be 950 who are not infected, but 5% = (100 - 95)% of these, i.e. Nasopharyngeal swabs mark the gold standard for sample collection in suspected respiratory tract infections but are unsuitable for widespread application, as they must be performed by medically trained personnel. m 2)g`[Hi i`2D@f8HL] k Antigen and Molecular Tests for COVID-19 The diagnostic testing field for COVID-19 is rapidly evolving, with many tests focused on diagnosing patients with active viral infections. At-home covid tests: What to know - The Washington Post XLSX Johns Hopkins Center for Health Security 2023 Mar;9:100067. doi: 10.1016/j.dscb.2023.100067. Fig 2. Conclusions: The clinical sensitivity of SARS-CoV-2 RT-PCR testing was only moderate at best. Looking at these three examples it seems that the test becomes more accurate as the overall probability of infection increases. Cost: $23.99 for two tests. -, Arevalo-Rodriguez I, Buitrago-Garcia D, Simancas-Racines D, Zambrano-Achig P, Campo RD, Ciapponi A, et al.. False-negative results of initial RT-PCR assays for COVID-19: A systematic review.