Saliva is a reliable and accessible source for the detection of SARS-CoV-2

Abstract

Objectives Investigate the feasibility of saliva sampling as a noninvasive and safer tool to detect SARS-CoV-2 and to compare its reproducibility and sensitivity with nasopharyngeal swab samples (NPS). The use of sample pools was also investigated. Methods 2107 paired samples were collected from asymptomatic health care and office workers in Mexico City. Sixty of these samples were also analyzed in two other independent laboratories for concordance analysis. Sample processing and analysis of virus genetic material were performed according to standard protocols described elsewhere. Pooling analysis was performed by analyzing the saliva pool and the individual pool components. Results The concordance between NPS and saliva results was 95.2% (Kappa: 0.727, p = 0.0001) and 97.9% without considering inconclusive results (Kappa: 0.852, p = 0.0001). Saliva had a lower number of inconclusive results than NPS (0.9% vs 1.9%). Furthermore, saliva shows a significantly higher concentration of both total RNA and viral copies than NPS. Comparison of our results with those of the other two laboratories shows 100% and 97% concordance. Saliva samples are stable without the use of any preservative, a positive SARS-CoV-2 sample can be detected 5, 10, and 15 days after collection when the sample is stored at 4 °C. Conclusions Our results indicate that saliva is as effective as NPS for the identification of SARS-CoV-2-infected asymptomatic patients, sample pooling facilitates the analysis of a larger number of samples with the benefit of cost reduction.

Aerosol transmission of SARS-CoV-2 due to the chimney effect in two high-rise housing drainage stacks

“…Moreover, the low attack rate in the 13 observed COVID-19 vertical outbreaks suggested that the amount of infectious aerosols in building drainage systems is not very high or the leaked amount of infectious aerosols is low. Unlike feces, nasal mucus, saliva, and sputum of infected individuals are known to contain viable SARS-CoV-2 (e.g., Rao et al, 2020 ; To et al, 2020 ; Wyllie et al, 2020 ; Herrera et al, 2021 ). Nasopharyngeal or oropharyngeal swabs ( Caulley et al, 2021 ) and early morning posterior oropharyngeal saliva collection ( Bastos et al, 2021 ) are used as diagnostic specimen type for SARS-CoV-2.…”

Evaluation of rapid antigen tests based on saliva for the detection of SARS‐CoV‐2

“…The utility of saliva for the detection of SARS-CoV-2 was demonstrated in other recent studies as well. [2][3][4] A disadvantage is the need for the RT-PCR resulting in a long time until result which may be problematic, especially in emergency rooms. To address this problem, in this study a rapid antigen test (RAT) CEcertified for the detection of SARS-CoV-2 using saliva (COVID-19 Antigen Test Cassette [hypersensitive colloidal gold]; Xiamen Zhongsheng Langjie Biotechnology Co., Ltd.) was evaluated.…”

Saliva Testing is a Robust Non-Invasive Method for SARS-CoV-2 RNA Detection

“…As a result, distinct results obtained when exploring the saliva samples for SARS-CoV-2 RNA detection were published. [12][13][14]23,24 The main parameter, characterizing the detection method, is the agreement between the results obtained by the method under investigation and the gold standard. Regarding the saliva and NP swab comparison, most studies provide good results of agreement, sometimes termed as overall percentage agreement (OPA).…”

“…This result is close to the top results, obtained comparing NP and saliva samples. 23,25 Interestingly, some studies claim that the RT-PCR test performed using saliva samples could be even more sensitive in comparison to NP swab samples, which is referred to as a gold standard. 26,27 To control the sample collection, purification, and analysis, internal controls are usually obligatory.…”