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
Meta-Analysis
. 2022 Sep 20;31(165):220014.
doi: 10.1183/16000617.0014-2022. Print 2022 Sep 30.

Performance of saline and water gargling for SARS-CoV-2 reverse transcriptase PCR testing: a systematic review and meta-analysis

Nicole Ngai Yung Tsang  1 , Hau Chi So  1 , Benjamin J Cowling  1 , Gabriel M Leung  1 , Dennis Kai Ming Ip  2
Affiliations
Meta-Analysis

Performance of saline and water gargling for SARS-CoV-2 reverse transcriptase PCR testing: a systematic review and meta-analysis

Nicole Ngai Yung Tsang et al. Eur Respir Rev. .

Abstract

The performance of gargling for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase (RT)-PCR testing has not been previously reviewed. This review systematically assessed the performance of saline and water gargling for SARS-CoV-2 RT-PCR testing in the settings of diagnosing and monitoring viral shedding.We included original studies comparing the performance of gargling and (oropharyngeal-)nasopharyngeal swabs for SARS-CoV-2 RT-PCR testing. Studies conducted in either suspected individuals or confirmed cases were included and analysed separately. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were examined using random-effects models.Gargles achieved a high overall sensitivity (91%), specificity (97%), PPV (95%) and NPV (91%) for SARS-CoV-2 RT-PCR testing. Studies using saline gargle and water gargle have an overall sensitivity of 97% and 86%, respectively. The sensitivity values were largely maintained for saline and water gargling on stratified analysis, for both diagnosis (96% and 92%) and viral shedding monitoring (98% and 78%). A higher sensitivity was also reported by studies using sterile saline (100%), a smaller amount of gargling solution (92% versus 87%) and a longer gargling duration (95% versus 86%).Our results supported the use of gargling as a sampling approach for SARS-CoV-2 RT-PCR testing, which achieved a high sensitivity for both diagnosis and viral shedding monitoring purposes. Further investigation on the comparative performance of different gargling mediums is needed to draw a definitive conclusion.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: B.J. Cowling consults for Roche and Sanofi Pasteur. All other authors declare no competing interests.

Figures

FIGURE 1
FIGURE 1
Study profile.
FIGURE 2
FIGURE 2
Meta-analysis of the sensitivity, specificity, positive predictive value and negative predictive value using (oropharyngeal–)nasopharyngeal swab ((O)NPS) as a reference standard. FN: false negative; FP: false positive; NPV: negative predictive value; PPV: positive predictive value; TN: true negative; TP: true positive; RE: random effects.
FIGURE 3
FIGURE 3
Meta-analysis of the sensitivity, specificity, positive predictive value and negative predictive value using (oropharyngeal–)nasopharyngeal swab ((O)NPS) as a reference standard for diagnostic testing in suspected individuals. FN: false negative; FP: false positive; NPV: negative predictive value; PPV: positive predictive value; TN: true negative; TP: true positive; RE: random effects.
FIGURE 4
FIGURE 4
Meta-analysis of the sensitivity, specificity, positive predictive value and negative predictive value using (oropharyngeal–)nasopharyngeal swab ((O)NPS) as a reference standard among studies consisting of confirmed cases. FN: false negative; FP: false positive; NPV: negative predictive value; PPV: positive predictive value; TN: true negative; TP: true positive; RE: random effects.
See this image and copyright information in PMC

Similar articles

  • Rapid, point-of-care antigen tests for diagnosis of SARS-CoV-2 infection.
    Dinnes J, Sharma P, Berhane S, van Wyk SS, Nyaaba N, Domen J, Taylor M, Cunningham J, Davenport C, Dittrich S, Emperador D, Hooft L, Leeflang MM, McInnes MD, Spijker R, Verbakel JY, Takwoingi Y, Taylor-Phillips S, Van den Bruel A, Deeks JJ; Cochrane COVID-19 Diagnostic Test Accuracy Group. Dinnes J, et al. Cochrane Database Syst Rev. 2022 Jul 22;7(7):CD013705. doi: 10.1002/14651858.CD013705.pub3. Cochrane Database Syst Rev. 2022. PMID: 35866452 Free PMC article.
  • Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19.
    Struyf T, Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Leeflang MM, Spijker R, Hooft L, Emperador D, Domen J, Tans A, Janssens S, Wickramasinghe D, Lannoy V, Horn SRA, Van den Bruel A; Cochrane COVID-19 Diagnostic Test Accuracy Group. Struyf T, et al. Cochrane Database Syst Rev. 2022 May 20;5(5):CD013665. doi: 10.1002/14651858.CD013665.pub3. Cochrane Database Syst Rev. 2022. PMID: 35593186 Free PMC article.
  • Antibody tests for identification of current and past infection with SARS-CoV-2.
    Fox T, Geppert J, Dinnes J, Scandrett K, Bigio J, Sulis G, Hettiarachchi D, Mathangasinghe Y, Weeratunga P, Wickramasinghe D, Bergman H, Buckley BS, Probyn K, Sguassero Y, Davenport C, Cunningham J, Dittrich S, Emperador D, Hooft L, Leeflang MM, McInnes MD, Spijker R, Struyf T, Van den Bruel A, Verbakel JY, Takwoingi Y, Taylor-Phillips S, Deeks JJ; Cochrane COVID-19 Diagnostic Test Accuracy Group. Fox T, et al. Cochrane Database Syst Rev. 2022 Nov 17;11(11):CD013652. doi: 10.1002/14651858.CD013652.pub2. Cochrane Database Syst Rev. 2022. PMID: 36394900 Free PMC article.
  • Thoracic imaging tests for the diagnosis of COVID-19.
    Ebrahimzadeh S, Islam N, Dawit H, Salameh JP, Kazi S, Fabiano N, Treanor L, Absi M, Ahmad F, Rooprai P, Al Khalil A, Harper K, Kamra N, Leeflang MM, Hooft L, van der Pol CB, Prager R, Hare SS, Dennie C, Spijker R, Deeks JJ, Dinnes J, Jenniskens K, Korevaar DA, Cohen JF, Van den Bruel A, Takwoingi Y, van de Wijgert J, Wang J, Pena E, Sabongui S, McInnes MD; Cochrane COVID-19 Diagnostic Test Accuracy Group. Ebrahimzadeh S, et al. Cochrane Database Syst Rev. 2022 May 16;5(5):CD013639. doi: 10.1002/14651858.CD013639.pub5. Cochrane Database Syst Rev. 2022. PMID: 35575286 Free PMC article.
  • Saline gargle collection method is comparable to nasopharyngeal/oropharyngeal swabbing for the molecular detection and sequencing of SARS-CoV-2 in Botswana.
    Lechiile K, Moyo S, Woo Kinshella M-L, Choga WT, Tawe L, Strysko J, Bagatiseng G, Kayda I, Seru K, Zuze BJL, Motshosi P, Mosepele M, Gobe I, Gaseitsiwe S, Mokomane M, Goldfarb DM. Lechiile K, et al. Microbiol Spectr. 2025 Jul;13(7):e0202324. doi: 10.1128/spectrum.02023-24. Epub 2025 May 22. Microbiol Spectr. 2025. PMID: 40401962 Free PMC article.
See all similar articles

Cited by

References

    1. World Health Organization . Weekly epidemiological update on COVID-19 – 6 July 2021. www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-1... Date last updated: 6 July 2022. Date accessed: 4 August 2022.
    1. World Health Organization . Weekly epidemiological update on COVID-19 – 11 January 2022. www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-1... Date last updated: 11 January 2022. Date accessed: 4 August 2022.
    1. Boum Y, Eyangoh S, Okomo M-C. Beyond COVID-19–will self-sampling and testing become the norm? Lancet Infect Dis 2021; 21: 1194–1195. doi: 10.1016/S1473-3099(21)00197-3 - DOI - PMC - PubMed
    1. World Health Organization . Laboratory Testing for Coronavirus Disease (COVID-19) in Suspected Human Cases: Interim Guidance, 19 March 2020. World Health Organization, Geneva; 2020.
    1. Centers for Disease Control and Prevention . Interim guidelines for collecting and handling of clinical specimens for COVID-19 testing. www.cdc.gov/coronavirus/2019-nCoV/lab/guidelines-clinical-specimens.html Date accessed: 7 June 2021. Date last updated: 15 July 2022.