COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Diagnosis Altawalah H, AlHuraish F, Alkandari WA, et al. Saliva specimens for detection of severe acute respiratory syndrome coronavirus 2 in Kuwait: A cross-sectional study. J Clin Virol. 2020 Nov;132:104652. doi: 10.1016/j.jcv.2020.104652. Epub 2020 Oct 1.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) and represents a global pandemic affecting more than 26 million people and has claimed >870,000 lives worldwide. Diagnostic tests for SARS-COV-2 infection commonly use nasopharyngeal swabs (NPS). As an alternative specimen, we investigated the potential use of the real-time reverse transcriptase PCR (RT-PCR) detection of SARS-COV-2 in saliva samples in large suspected-COVID-19 patients in Kuwait. NPS and saliva samples pairs were prospectively collected from 891 COVID-19 suspected patients in Kuwait and analyzed using TaqPath™ COVID-19 multiplex RT-PCR. Of the 891 patients, 38.61 % (344/891) were positive for SARS-CoV-2, 4.83 % (43/891) were equivocal, and 56.56 % (504/891) were negative with NPS by RT-PCR. For saliva, 34.23 % (305/891) were positive for SARS-CoV-2, 3.14 (28/891) were equivocal, and 62.63 % (558/891) were negative. From 344 confirmed cases for SARS-CoV-2 with NPS samples, 287 (83.43 %) (95 % CI, 79.14-86.99) were positive with saliva specimens. Moreover, the diagnostic sensitivity and specificity of RT-PCR for the diagnosis of COVID-19 in saliva were 83.43 % (95 % CI: 79.07-87.20) and 96.71 % (95 % CI: 94.85-98.04 %), respectively. An analysis of the agreement between the NPS and saliva specimens demonstrated 91.25 % observed agreement (? coefficient = 0.814, 95 % CI, 0.775-0.854). This study demonstrates that saliva can be a noninvasive specimen for detection of SARS-CoV-2 by RT-PCR.

Discipline / Specialty Area Score
Infectious Disease
Public Health
Family Medicine (FM)/General Practice (GP)
General Internal Medicine-Primary Care(US)
Hospital Doctor/Hospitalists
Internal Medicine
Comments from MORE raters

Infectious Disease rater

This study compared the yield of RT PCR on nasopharyngeal versus saliva samples of 891 persons suspected to have covid-19. Sensitivity was 83.43% and specificity 96.71%. Saliva samples would be a far more convenient method to test for covid-19. The relatively low sensitivity remains a concern.

Infectious Disease rater

Although there was 91.25% agreement overall between NP swab and saliva rapid PCR, amongst those positive for COVID-19 by NP swab, only 83.43 % were positive by saliva testing.

Internal Medicine rater

This study brought more evidence that saliva-based testing is a promising alternative sampling for SARS-CoV-2 detection by RT-PCR and could simplify and accelerate COVID-19 diagnosis.