Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct 29;11(1):1993535.
doi: 10.1080/20008686.2021.1993535. eCollection 2021.

Detection of SARS-CoV-2 by rapid antigen tests on saliva in hospitalized patients with COVID-19

Yang De Marinis  1   2   3 , Anne-Katrine Pesola  4 , Anna Söderlund Strand  4 , Astrid Norman  5 , Gustav Pernow  5 , Markus Aldén  1 , Runtao Yang  6 , Magnus Rasmussen  5
Affiliations

Detection of SARS-CoV-2 by rapid antigen tests on saliva in hospitalized patients with COVID-19

Yang De Marinis et al. Infect Ecol Epidemiol. .

Abstract

Background: The COVID-19 pandemic presents great challenges on transmission prevention, and rapid diagnosis is essential to reduce the disease spread. Various diagnostic methods are available to identify an ongoing infection by nasopharyngeal (NPH) swab sampling. However, the procedure requires handling by health care professionals, and therefore limits the application in household and community settings.

Objectives: In this study, we aimed to determine if the detection of SARS-CoV-2 can be performed alternatively on saliva specimens by rapid antigen test.

Study design: Saliva and NPH specimens were collected from 44 patients with confirmed COVID-19. To assess the diagnostic accuracy of point-of-care SARS-CoV-2 rapid antigen test on saliva specimens, we compared the performance of four test products.

Results: RT-qPCR was performed and NPH and saliva sampling had similar Ct values, which associated with disease duration. All four antigen tests showed similar trend in detecting SARS-CoV-2 in saliva, but with variation in the ability to detect positive cases. The rapid antigen test with the best performance could detect up to 67% of the positive cases with Ct values lower than 25, and disease duration shorter than 10 days.

Conclusion: Our study therefore supports saliva testing as an alternative diagnostic procedure to NPH testing, and that rapid antigen test on saliva provides a potential complement to PCR test to meet increasing screening demand.

Keywords: COVID-19; SARS-CoV-2; antigen test; saliva.

PubMed Disclaimer

Conflict of interest statement

YDM is the founder of and has an equity interest in ZetaGene Ltd. (Sweden), a company that is developing microfluidic technologies for point-of-care diagnostic solutions.

Figures

Figure 1.
Figure 1.
Detection of SARS-CoV-2 in saliva specimens and nasopharyngeal (NPH) swab specimens. samples were obtained from 44 patients with COVID-19. (a) detection of SARS-CoV-2 is presented by RT-PCR Ct values in patients with available NPH and saliva samples (n = 40). the lines indicate samples from the same patient. Ct values in NPH are significantly lower than those in saliva (p < 0.01 by Wilcoxon signed-ranked test). Pearson’s correlation coefficient was performed on RT-PCR Ct values above detection threshold (Ct<40) in (b) NPH and saliva samples Ct values (n = 32; r = 0.64, p < 0.001); (c) NPH Ct values and symptom duration (n = 40; r = 0.58, p < 0.001); (d) saliva Ct values and symptom duration (n = 34; r = 0.54, p < 0.001)
Figure 1.
Figure 1.
(Continued)
Figure 2.
Figure 2.
Positive detection rate of SARS-CoV-2 in saliva samples by four SARS-CoV-2 rapid antigen tests: Flowflex (Flowflex SARS-CoV-2 rapid antigen test, ZetaGene-Hughes healthcare, Sweden/UK; blue bars), Panbio (Panbio COVID-19 ag rapid test, Abbott, UK; Orange bars), Joinstar (Joinstar COVID-19 antigen rapid test, China; grey bars), PCL (PCL COVID-19 ag antigen gold saliva lateral flow test, Korea; yellow bars). Saliva specimens were collected from patients with confirmed COVID-19 (n = 44), and 34 samples were above the threshold of detection by RT-PCR (Ct<40). Patients were grouped according to (a) PCR Ct values: Ct<25; 25≤ Ct<29; 29≤ Ct<40; (b) days after COVID-19 symptoms onset: Days≤5; 5< Days≤10; Days≥10; (c) Ct<25, Days<10
See this image and copyright information in PMC

References

    1. Organization WH . WHO Coronavirus (COVID-19) Dashboard. Geneva: World Health Organization; 2021.
    1. Mahajan A, Manchikanti L.. Value and validity of coronavirus antibody testing. Pain Physician. 2020;4S;23(8;4S):S381–7. - PubMed
    1. La Marca A, Capuzzo M, Paglia T, et al. Testing for SARS-CoV-2 (COVID-19): a systematic review and clinical guide to molecular and serological in-vitro diagnostic assays. Reprod Biomed Online. 2020;41:483–499. - PMC - PubMed
    1. Bastos ML, Perlman-Arrow S, and Menzies D, et al. The sensitivity and costs of testing for SARS-CoV-2 Infection with saliva versus nasopharyngeal swabs: a systematic review and meta-analysis. Ann Intern Med. 2021. 174 (4) ;501–510 doi: 10.7326/M20-6569. - DOI - PMC - PubMed
    1. Wang X, Tan L, Wang X, et al. Comparison of nasopharyngeal and oropharyngeal swabs for SARS-CoV-2 detection in 353 patients received tests with both specimens simultaneously. Int J Infect Dis. 2020;94:107–109. - PMC - PubMed

LinkOut - more resources