{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T04:22:56Z","timestamp":1772252576289,"version":"3.50.1"},"reference-count":59,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,2,21]],"date-time":"2021-02-21T00:00:00Z","timestamp":1613865600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["IDB\/04585\/2020"],"award-info":[{"award-number":["IDB\/04585\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>The rapid and accurate testing of SARS-CoV-2 infection is still crucial to mitigate, and eventually halt, the spread of this disease. Currently, nasopharyngeal swab (NPS) and oropharyngeal swab (OPS) are the recommended standard sampling techniques, yet, these have some limitations such as the complexity of collection. Hence, several other types of specimens that are easier to obtain are being tested as alternatives to nasal\/throat swabs in nucleic acid assays for SARS-CoV-2 detection. This study aims to critically appraise and compare the clinical performance of RT-PCR tests using oral saliva, deep-throat saliva\/posterior oropharyngeal saliva (DTS\/POS), sputum, urine, feces, and tears\/conjunctival swab (CS) against standard specimens (NPS, OPS, or a combination of both). In this systematic review and meta-analysis, five databases (PubMed, Scopus, Web of Science, ClinicalTrial.gov and NIPH Clinical Trial) were searched up to the 30th of December, 2020. Case-control and cohort studies on the detection of SARS-CoV-2 were included. The methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2). We identified 1560 entries, 33 of which (1.1%) met all required criteria and were included for the quantitative data analysis. Saliva presented the higher accuracy, 92.1% (95% CI: 70.0\u201398.3), with an estimated sensitivity of 83.9% (95% CI: 77.4\u201388.8) and specificity of 96.4% (95% CI: 89.5\u201398.8). DTS\/POS samples had an overall accuracy of 79.7% (95% CI: 43.3\u201395.3), with an estimated sensitivity of 90.1% (95% CI: 83.3\u201396.9) and specificity of 63.1% (95% CI: 36.8\u201389.3). The remaining index specimens could not be adequately assessed given the lack of studies available. Our meta-analysis shows that saliva samples from the oral region provide a high sensitivity and specificity; therefore, these appear to be the best candidates for alternative specimens to NPS\/OPS in SARS-CoV-2 detection, with suitable protocols for swab-free sample collection to be determined and validated in the future. The distinction between oral and extra-oral salivary samples will be crucial, since DTS\/POS samples may induce a higher rate of false positives. Urine, feces, tears\/CS and sputum seem unreliable for diagnosis. Saliva testing may increase testing capacity, ultimately promoting the implementation of truly deployable COVID-19 tests, which could either work at the point-of-care (e.g. hospitals, clinics) or at outbreak control spots (e.g., schools, airports, and nursing homes).<\/jats:p>","DOI":"10.3390\/diagnostics11020363","type":"journal-article","created":{"date-parts":[[2021,2,21]],"date-time":"2021-02-21T22:04:15Z","timestamp":1613945055000},"page":"363","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Diagnosis of SARS-Cov-2 Infection by RT-PCR Using Specimens Other Than Naso- and Oropharyngeal Swabs: A Systematic Review and Meta-Analysis"],"prefix":"10.3390","volume":"11","author":[{"given":"V\u00e2nia M.","family":"Moreira","sequence":"first","affiliation":[{"name":"\u00c1rea Departamental de Engenharia Qu\u00edmica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Em\u00eddio Navarro 1, 1959-007 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6584-1199","authenticated-orcid":false,"given":"Paulo","family":"Mascarenhas","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"Evidence-Based Hub, CiiEM, Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2503-260X","authenticated-orcid":false,"given":"Vanessa","family":"Machado","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"Evidence-Based Hub, CiiEM, Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1019-8263","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Botelho","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"Evidence-Based Hub, CiiEM, Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0167-4077","authenticated-orcid":false,"given":"Jos\u00e9 Jo\u00e3o","family":"Mendes","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"Evidence-Based Hub, CiiEM, Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0176-5585","authenticated-orcid":false,"given":"Nuno","family":"Taveira","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"Research Institute for Medicines, Faculty of Pharmacy, University of Lisbon, 1649-003 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4508-7379","authenticated-orcid":false,"given":"M. Gabriela","family":"Almeida","sequence":"additional","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o Interdisciplinar Egas Moniz (CiiEM), Egas Moniz\u2013Cooperativa de Ensino Superior CRL, Campus Universit\u00e1rio, Quinta da Granja, 2829-511 Caparica, Portugal"},{"name":"UCIBIO, REQUIMTE, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,21]]},"reference":[{"key":"ref_1","unstructured":"(2020, December 01). IHME Covid Projections. Available online: https:\/\/covid19.healthdata.org\/global."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"455","DOI":"10.26452\/ijrps.v11iSPL1.2811","article-title":"A review: Coronavirus, its types, and impact of covid-19 on global wealth","volume":"11","author":"Budhrani","year":"2020","journal-title":"Int. J. Res. Pharm. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"465","DOI":"10.3389\/fmed.2020.00465","article-title":"Saliva as a Candidate for COVID-19 Diagnostic Testing: A Meta-Analysis","volume":"7","author":"Czumbel","year":"2020","journal-title":"Front. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.jacl.2020.12.008","article-title":"Impact of prior statin use on clinical outcomes in COVID-19 patients: Data from tertiary referral hospitals during COVID-19 pandemic in Italy","volume":"15","author":"Mitacchione","year":"2020","journal-title":"J. Clin. Lipidol."},{"key":"ref_5","unstructured":"ECDC (2020, December 01). Diagnostic Testing and Screening for SARS-CoV-2. Available online: https:\/\/www.ecdc.europa.eu\/en\/covid-19\/latest-evidence\/diagnostic-testing."},{"key":"ref_6","unstructured":"Evans, R.W. (2020). Diagnostic Testing for SARS-CoV-2. WHO."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"112454","DOI":"10.1016\/j.bios.2020.112454","article-title":"Diagnostics for SARS-CoV-2 detection: A comprehensive review of the FDA-EUA COVID-19 testing landscape","volume":"165","author":"Ravi","year":"2020","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1002\/hed.26232","article-title":"Respiratory sampling for severe acute respiratory syndrome coronavirus 2: An Overview","volume":"42","author":"See","year":"2020","journal-title":"Head Neck"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sapkota, D., S\u00f8land, T.M., Galtung, H.K., Sand, L.P., Giannecchini, S., To, K.K.W., Mendes-Correa, M.C., Giglio, D., Hass\u00e9us, B., and Braz-Silva, P.H. (2020). COVID-19 salivary signature: Diagnostic and research opportunities. J. Clin. Pathol.","DOI":"10.1136\/jclinpath-2020-206834"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e76","DOI":"10.1056\/NEJMvcm2010260","article-title":"How to Obtain a Nasopharyngeal Swab Specimen","volume":"382","author":"Marty","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.1177\/0022034520960070","article-title":"Saliva in the Diagnosis of COVID-19: A Review and New Research Directions","volume":"99","author":"Fernandes","year":"2020","journal-title":"J. Dent. Res."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Barat, B., Das, S., De Giorgi, V., Henderson, D.K., Kopka, S., Lau, A.F., Miller, T., Moriarty, T., Palmore, T.N., and Sawney, S. (2020). Pooled Saliva Specimens for SARS-CoV-2 Testing. J. Clin. Microbiol., 59.","DOI":"10.1101\/2020.10.02.20204859"},{"key":"ref_13","first-page":"1858002","article-title":"Performance of at-home self-collected saliva and nasal-oropharyngeal swabs in the surveillance of COVID-19","volume":"13","author":"Mamana","year":"2020","journal-title":"medRxiv"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1186\/s12985-020-01359-1","article-title":"Evaluation of SARS-CoV-2 viral RNA in fecal samples","volume":"17","author":"Mesoraca","year":"2020","journal-title":"Virol. J."},{"key":"ref_15","first-page":"10","article-title":"Saliva sampling and its direct lysis, an excellent option to increase the number of SARS-CoV-2 diagnostic tests in settings with supply shortages","volume":"58","author":"Espinoza","year":"2020","journal-title":"J. Clin. Microbiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"285.e1","DOI":"10.1016\/j.cmi.2020.05.001","article-title":"Saliva sample as a non-invasive specimen for the diagnosis of coronavirus disease 2019: A cross-sectional study","volume":"27","author":"Pasomsub","year":"2020","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1676","DOI":"10.1002\/jmv.25936","article-title":"SARS-CoV-2 can be detected in urine, blood, anal swabs, and oropharyngeal swabs specimens","volume":"92","author":"Peng","year":"2020","journal-title":"J. Med. Virol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"104438","DOI":"10.1016\/j.jcv.2020.104438","article-title":"Validation of SARS-CoV-2 detection across multiple specimen types","volume":"128","author":"Perchetti","year":"2020","journal-title":"J. Clin. Virol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Rao, M., Rashid, F.A., Sabri, F.S.A.H., Jamil, N.N., Zain, R., Hashim, R., Amran, F., Kok, H.T., Samad, M.A.A., and Ahmad, N. (2020). Comparing Nasopharyngeal Swab and Early Morning Saliva for the Identification of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clin. Infect. Dis.","DOI":"10.1093\/cid\/ciaa1156"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3393","DOI":"10.2147\/IDR.S275152","article-title":"Saliva as an alternative specimen for molecular COVID-19 testing in community settings and population-based screening","volume":"13","author":"Senok","year":"2020","journal-title":"Infect. Drug Resist."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1199","DOI":"10.1177\/0022034520940292","article-title":"Oropharyngeal Secretion as Alternative for SARS-CoV-2 Detection","volume":"99","author":"Yu","year":"2020","journal-title":"J. Dent. Res."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Yokota, I., Shane, P.Y., Okada, K., Unoki, Y., Yang, Y., Inao, T., Sakamaki, K., Iwasaki, S., Hayasaka, K., and Sugita, J. (2020). Mass screening of asymptomatic persons for SARS-CoV-2 using saliva. Clin. Infect. Dis.","DOI":"10.1101\/2020.08.13.20174078"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1089","DOI":"10.1515\/cclm-2020-0187","article-title":"Comparison of throat swabs and sputum specimens for viral nucleic acid detection in 52 cases of novel coronavirus (SARS-Cov-2)-infected pneumonia (COVID-19)","volume":"58","author":"Lin","year":"2020","journal-title":"Clin. Chem. Lab. Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1097\/ICO.0000000000002562","article-title":"Detection of Coronavirus in Tear Samples of Hospitalized Patients With Confirmed SARS-CoV-2 From Oropharyngeal Swabs","volume":"40","author":"Dutescu","year":"2021","journal-title":"Cornea"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2939","DOI":"10.1093\/cid\/ciaa797","article-title":"Posterior Oropharyngeal Saliva for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)","volume":"71","author":"Wong","year":"2020","journal-title":"Clin. Infect. Dis."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1016\/j.cca.2020.09.018","article-title":"SARS-CoV-2 identification and IgA antibodies in saliva: One sample two tests approach for diagnosis","volume":"510","author":"Aita","year":"2020","journal-title":"Clin. Chim. Acta"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.jmoldx.2020.10.018","article-title":"Performance of Severe Acute Respiratory Syndrome Coronavirus 2 Real-Time RT-PCR Tests on Oral Rinses and Saliva Samples","volume":"23","author":"Babady","year":"2020","journal-title":"J. Mol. Diagn."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1356","DOI":"10.1080\/22221751.2020.1775133","article-title":"Evaluating the use of posterior oropharyngeal saliva in a point-of-care assay for the detection of SARS-CoV-2","volume":"9","author":"Chen","year":"2020","journal-title":"Emerg. Microbes Infect."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"104519","DOI":"10.1016\/j.jcv.2020.104519","article-title":"Evaluation of simple nucleic acid extraction methods for the detection of SARS-CoV-2 in nasopharyngeal and saliva specimens during global shortage of extraction kits","volume":"129","author":"Chu","year":"2020","journal-title":"J. Clin. Virol."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Hanson, K.E., Barker, A.P., Hillyard, D.R., Gilmore, N., Barrett, J.W., Orlandi, R.R., and Shakirb, S.M. (2020). Self-collected anterior nasal and saliva specimens versus health care worker-collected nasopharyngeal swabs for the molecular detection of SARS-CoV-2. J. Clin. Microbiol., 58.","DOI":"10.1128\/JCM.01824-20"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1220","DOI":"10.1038\/s41433-020-0965-2","article-title":"Detection of severe acute respiratory syndrome Coronavirus-2 in the tears of patients with Coronavirus disease 2019","volume":"34","author":"Karimi","year":"2020","journal-title":"Eye"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Procop, G.W., Shrestha, N.K., Vogel, S., van Sickle, K., Harrington, S., Rhoads, D.D., Rubin, B.P., and Terpeluk, P. (2020). A Direct Comparison of Enhanced Saliva to Nasopharyngeal Swab for the Detection of SARS-CoV-2 in Symptomatic Patients. J. Clin. Microbiol., 58.","DOI":"10.1128\/JCM.01946-20"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Sohn, Y., Jeong, S.J., Chung, W.S., Hyun, J.H., Baek, Y.J., Cho, Y., Kim, J.H., Ahn, J.Y., Choi, J.Y., and Yeom, J.-S. (2020). Assessing Viral Shedding and Infectivity of Asymptomatic or Mildly Symptomatic Patients with COVID-19 in a Later Phase. J. Clin. Med., 9.","DOI":"10.3390\/jcm9092924"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1016\/j.bjid.2020.08.001","article-title":"Saliva is a reliable, non-invasive specimen for SARS-CoV-2 detection","volume":"24","author":"Vaz","year":"2020","journal-title":"Braz. J. Infect. Dis."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1007\/s15010-020-01548-8","article-title":"Higher viral loads in asymptomatic COVID-19 patients might be the invisible part of the iceberg","volume":"49","author":"Hasanoglu","year":"2020","journal-title":"Infection"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1001\/jamaophthalmol.2020.1291","article-title":"Characteristics of Ocular Findings of Patients with Coronavirus Disease 2019 (COVID-19) in Hubei Province, China","volume":"138","author":"Wu","year":"2020","journal-title":"Jama Ophthalmol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1116","DOI":"10.1590\/1806-9282.66.8.1116","article-title":"Comparison of saliva and oro-nasopharyngeal swab sample in the molecular diagnosis of COVID-19","volume":"66","author":"Koroglu","year":"2020","journal-title":"Rev. Assoc. Med. Bras."},{"key":"ref_38","first-page":"9","article-title":"Sensitivity of Nasopharyngeal Swabs and Saliva for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2","volume":"27","author":"Jamal","year":"2020","journal-title":"Clin. Infect. Dis."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Kandel, C., Zheng, J., McCready, J., Serbanescu, M.A., Racher, H., Desaulnier, M., Powis, J.E., Vojdani, K., Finlay, L., and Sheldrake, E. (2020). Detection of SARS-CoV-2 from Saliva as Compared to Nasopharyngeal Swabs in Outpatients. Viruses, 12.","DOI":"10.3390\/v12111314"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"e287","DOI":"10.3346\/jkms.2020.35.e287","article-title":"Viral Load Kinetics of SARS-CoV-2 Infection in Saliva in Korean Patients: A Prospective Multi-center Comparative Study","volume":"35","author":"Kim","year":"2020","journal-title":"J. Korean Med. Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1612","DOI":"10.1093\/infdis\/jiaa487","article-title":"Prospective Study Comparing Deep Throat Saliva With Other Respiratory Tract Specimens in the Diagnosis of Novel Coronavirus Disease 2019","volume":"222","author":"Lai","year":"2020","journal-title":"J. Infect. Dis."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"104567","DOI":"10.1016\/j.jcv.2020.104567","article-title":"Challenges in use of saliva for detection of SARS CoV-2 RNA in symptomatic outpatients","volume":"130","author":"Landry","year":"2020","journal-title":"J. Clin. Virol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Leung, E.C.M., Chow, V.C.Y., Lee, M.K.P., and Lai, R.W.M. (2020). Deep throat saliva as an alternative diagnostic specimen type for the detection of SARS-CoV-2. J. Med. Virol.","DOI":"10.1002\/jmv.26258"},{"key":"ref_44","unstructured":"FDA (2020, December 01). Emergency Use Authorization Issued in August 2020, Available online: https:\/\/www.fda.gov\/news-events\/press-announcements\/coronavirus-covid-19-update-fda-issues-emergency-use-authorization-yale-school-public-health."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Moher, D., Liberati, A., Tetzlaff, J., Altman, D.G., Altman, D., Antes, G., Atkins, D., Barbour, V., Barrowman, N., and Berlin, J.A. (2009). Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. Plos Med., 6.","DOI":"10.1371\/journal.pmed.1000097"},{"key":"ref_46","unstructured":"Bristol, M.S. (2020, December 01). QUADAS2: Background Document. Available online: https:\/\/www.bristol.ac.uk\/media-library\/sites\/quadas\/migrated\/documents\/background-doc.pdf."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1002\/jrsm.1411","article-title":"Risk-of-bias VISualization (robvis): An R package and Shiny web app for visualizing risk-of-bias assessments","volume":"12","author":"McGuinness","year":"2021","journal-title":"Res. Synth. Methods"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Freeman, S.C., Kerby, C.R., Patel, A., Cooper, N.J., Quinn, T., and Sutton, A.J. (2019). Development of an interactive web-based tool to conduct and interrogate meta-analysis of diagnostic test accuracy studies: MetaDTA. Bmc Med. Res. Methodol., 19.","DOI":"10.1186\/s12874-019-0724-x"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1111\/1469-0691.12474","article-title":"Systematic reviews and meta-analyses of diagnostic test accuracy","volume":"20","author":"Leeflang","year":"2014","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1093\/biostatistics\/kxl004","article-title":"A unification of models for meta-analysis of diagnostic accuracy studies","volume":"8","author":"Harbord","year":"2007","journal-title":"Biostatistics"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1","DOI":"10.18637\/jss.v049.i05","article-title":"End-Users: R as a Computational Back-End","volume":"49","author":"Wallace","year":"2012","journal-title":"J. Stat. Softw."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1520","DOI":"10.1016\/j.cmi.2020.07.020","article-title":"Viable SARS-CoV-2 in various specimens from COVID-19 patients","volume":"26","author":"Jeong","year":"2020","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1938","DOI":"10.1002\/jmv.25905","article-title":"Positive result of Sars-Cov-2 in faeces and sputum from discharged patients with COVID-19 in Yiwu, China","volume":"92","author":"Li","year":"2020","journal-title":"J. Med. Virol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1186\/s13054-020-02893-8","article-title":"SARS-CoV-2 viral load in sputum correlates with risk of COVID-19 progression","volume":"24","author":"Yu","year":"2020","journal-title":"Crit. Care"},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Ceron, J., Lamy, E., Martinez-Subiela, S., Lopez-Jornet, P., Capela-Silva, F., Eckersall, P., and Tvarijonaviciute, A. (2020). Use of Saliva for Diagnosis and Monitoring the SARS-CoV-2: A General Perspective. J. Clin. Med., 9.","DOI":"10.3390\/jcm9051491"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1002\/jmv.25786","article-title":"Stability issues of RT-PCR testing of SARS-CoV-2 for hospitalized patients clinically diagnosed with COVID-19","volume":"92","author":"Li","year":"2020","journal-title":"J. Med. Virol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/S0140-6736(20)30183-5","article-title":"Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China","volume":"395","author":"Huang","year":"2020","journal-title":"Lancet"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"e195","DOI":"10.3346\/jkms.2020.35.e195","article-title":"Clinical significance of a high SARS-CoV-2 viral load in the Saliva","volume":"35","author":"Yoon","year":"2020","journal-title":"J. Korean Med. Sci."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"870","DOI":"10.1038\/s41587-020-0513-4","article-title":"CRISPR\u2013Cas12-based detection of SARS-CoV-2","volume":"38","author":"Broughton","year":"2020","journal-title":"Nat. Biotechnol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/11\/2\/363\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:27:27Z","timestamp":1760160447000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/11\/2\/363"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,21]]},"references-count":59,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["diagnostics11020363"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics11020363","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2021.01.19.21250094","asserted-by":"object"}]},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,21]]}}}