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. 2021 Nov;101(3):115450.
doi: 10.1016/j.diagmicrobio.2021.115450. Epub 2021 Jun 6.

The reliability of saliva for the detection of SARS-CoV-2 in symptomatic and asymptomatic patients: Insights on the diagnostic performance and utility for COVID-19 screening

Khaled J Alkhateeb  1 , Meredith N Cahill  2 , Adam S Ross  3 , Forest W Arnold  2 , James W Snyder  4
Affiliations

The reliability of saliva for the detection of SARS-CoV-2 in symptomatic and asymptomatic patients: Insights on the diagnostic performance and utility for COVID-19 screening

Khaled J Alkhateeb et al. Diagn Microbiol Infect Dis. 2021 Nov.

Abstract

Current literature has focused on testing saliva in symptomatic patients, and little information is available regarding saliva performance in asymptomatic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. We compared paired saliva and nasopharyngeal swabs (NPS) collected from 33 symptomatic and 12 asymptomatic known SARS-CoV-2-positive patients. Saliva had an overall sensitivity of 59%, a specificity of 95%, and a negative predictive value of 98%. Saliva demonstrated higher sensitivity in symptomatic (80%) vs. asymptomatic individuals (36%) (P = 0.006), and in high-risk (symptomatic, febrile and/or with comorbidities) (82%) vs. low-risk (asymptomatic, afebrile, and no comorbidities) (22%) patients (P = 0.0002). Cycle threshold (Ct) values in NPS specimens were higher in saliva-negative vs. saliva-positive cases (P = 0.02 and <0.001). Overall, these findings show that despite saliva's low sensitivity in asymptomatic SARS-CoV-2 infections, it can detect infections with lower Ct values and a potentially higher chance of viral transmission. Additional studies are warranted to fully evaluate saliva as a screening test for coronavirus disease-2019.

Keywords: Asymptomatic; COVID-19; Nasopharyngeal swab; SARS-CoV-2; Saliva; Screening.

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Figures

Fig 1
Fig. 1
Ct values in paired NPS and saliva samples.
Fig 2
Fig. 2
Mean Ct value by test type (NPS vs. saliva) across different patient categories (Welch two sample t-tests).
Fig 3
Fig. 3
Difference in mean NPS Ct value between saliva-negative and saliva-positive samples (Welch two sample t-tests).
See this image and copyright information in PMC

References

    1. Azzi L, Carcano G, Gianfagna F, Grossi P, Gasperina DD, Genoni A, et al. Saliva is a reliable tool to detect SARS-CoV-2. J Infect. 2020;81:e45–e50. doi: 10.1016/j.jinf.2020.04.005. - DOI - PMC - PubMed
    1. Becker D, Sandoval E, Amin A, De Hoff P, Diets A, Leonetti N, et al. Saliva is less sensitive than nasopharyngeal swabs for COVID-19 detection in the community setting. 2020. medRxiv:2020.2005.2011.20092338. doi:10.1101/2020.05.11.20092338
    1. Berenger BM, Conly JM, Fonseca K, Hu J, Louie T, Schneider AR, et al. Saliva collected in universal transport media is an effective, simple and high-volume amenable method to detect SARS-CoV-2. Clin Microbiol Infect. 2020;27:656–657. doi: 10.1016/j.cmi.2020.10.035. - DOI - PMC - PubMed
    1. Caulley L, Corsten M, Eapen L, Whelan J, Angel JB, Antonation K, et al. Salivary detection of COVID-19. Ann Intern Med. 2020;174:131–133. doi: 10.7326/M20-4738. - DOI - PMC - PubMed
    1. Chau NVV, Thanh Lam V, Thanh Dung N, Yen LM, Minh NNQ, Hung LM, et al. The natural history and transmission potential of asymptomatic SARS-CoV-2 infection. Clin Infect Dis. 2020;71:2679–2687. doi: 10.1093/cid/ciaa711. - DOI - PMC - PubMed