Stability of SARS-CoV-2 RNA in Nonsupplemented Saliva

Ott, Isabel M.; Strine, Madison S.; Watkins, Anne E.; Boot, Maikel; Kalinich, Chaney C.; Harden, Christina A.; Vogels, Chantal B.F.; Casanovas‐Massana, Arnau; Moore, Adam J.; Muenker, M. Catherine; Nakahata, Maura; Tokuyama, Maria; Nelson, Allison; Fournier, John; Bermejo, Santos; Campbell, Melissa; Datta, Rupak; Cruz, Charles S. Dela; Farhadian, Shelli; Ko, Albert Icksang; Iwasaki, Akiko; Grubaugh, Nathan D.; Wilen, Craig B.; Wyllie, Anne L.

doi:10.3201/eid2704.204199

Cited by 69 publications

(71 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The significant decrease of SARS-CoV-2 detection in OP after mouth washing and the remaining detection of the human cellular control (HNRP), in saliva, suggest that the virus detection corresponds more to it accumulation in buccal cavity rather than a direct secretion by salivary glands [34]. These data could explain some mitigate results obtained by direct drooling into plastic tubes for COVID-19 diagnosis [35,36].…”

Section: Discussionmentioning

confidence: 94%

Mouth Washing Impaired SARS-CoV-2 Detection in Saliva

Costa

Nicolas

Tissot‐Dupont

et al. 2021

Preprint

View full text Add to dashboard Cite

Background. A previous study demonstrated the performance of the Salivette® (SARSTEDT, Numbrecht, Germany) as a homogeneous saliva collection system to diagnose COVID-19 by RT-qPCR, notably for symptomatic and asymptomatic patients. However, for convalescent patients, the corroboration of molecular detection of SARS-CoV-2 in paired nasopharyngeal swabs (NPS) and saliva samples was unsatisfactory. Objectives. The aim of the present work was to assess the concordance level of SARS-CoV-2 detection between paired sampling of NPSs and saliva collected with Salivette® at two time points, with ten days of interval. Results. A total of 319 paired samples from 145 outpatients (OP) and 51 healthcare workers (HW) were collected. Due to significant waiting rate at hospital, most of the patients ate and/or drank in waiting their turn. Consequently, a mouth washing was systematically proposed prior saliva collection. None of the HW were diagnosed SARS-CoV-2 positive using NPS or saliva specimens at both time points (n=95) by RT-qPCR. The virus was detected in 56.3% (n=126/224) of the NPS samples from OP, but solely 26.8% (n=60/224) of the paired saliva specimens. The detection of the internal cellular control, the human RNase P, in more than 98% of the saliva samples, underlined that the low sensitivity of saliva specimens (45.2%) for SARS-CoV-2 detection was not attributed to an improper saliva sample storing or RNA extraction. Conclusions. Then, the mouth washing decreased viral load of buccal cavity conducting to impairment of SARS-CoV-2 detection. Viral loads in saliva neo-produced appeared insufficient for molecular detection of SARS-CoV-2. At the time that saliva tests could be a rapid, simple and noninvasive strategy to assess on large scale schooled children in France, the determination of the performance of saliva collection become imperative to standardize procedures.

show abstract

Section: Discussionmentioning

confidence: 94%

Mouth Washing Impaired SARS-CoV-2 Detection in Saliva

Costa

Nicolas

Tissot‐Dupont

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…RNA samples of patients infected with SARS-CoV-2 have shown to be stable at 4°C, or room temperature for prolonged periods of time (weeks). This contrasts with human RNA, which degrades in the absence of stabilization buffers [ 21 ]. Yet, if human saliva RNA is placed in TRIzol, it can be stored at –80°C and remains stable for more than two years without the need of RNAse inhibitors [ 22 ].…”

Section: Discussionmentioning

confidence: 99%

“…This reagent is not only used for extraction, but also serves well as a storage medium. Taking into consideration that RNA of SARS-CoV-2 does not require specialized buffers for RNA stabilization and is stable at various temperatures [ 21 ], the use of TRIzol for extraction of SARS-CoV-2 RNA is promising, can decrease testing costs, inactivate the virus, and obtain stable RNA without the need of cold handling. This is particularly important for limited resources scenarios, where massive testing is required despite economic shortages.…”

Section: Discussionmentioning

confidence: 99%

Development of an alternative saliva test for diagnosis of SARS-CoV-2 using TRIzol: Adapting to countries with lower incomes looking for a large-scale detection program

et al. 2021

View full text Add to dashboard Cite

The use of saliva for the diagnosis of SARS-CoV-2 has shown to be a good alternative to nasopharyngeal swabs (NPS), since it permits self-collection, avoids the exposure of healthy persons to infected patients, reduces waiting times, eliminates the need of personal protective equipment and is non-invasive. Yet current saliva testing is still expensive due to the need of specialized tubes containing buffers to stabilize the RNA of SARS-CoV-2 and inactivate the virus. These tubes are expensive and not always accessible in sufficient quantities. We now developed an alternative saliva testing method, using TRIzol for extraction, viral inactivation, and storage of SARS-CoV-2 RNA, combined with RT-qPCR, which was comparable in its performance to NPS. Paired saliva samples and NPS were taken from 15 asymptomatic healthcare workers and one patient with SARS-CoV-2. Further 13 patients with SARS-CoV-2 were only saliva-tested. All the tests were performed according to CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel. Saliva (4 mL) was taken in sterile 50 mL tubes, 1.5 mL TRIzol were added and mixed. Our results show that 5 μL of saliva RNA extracted with TRIzol allow for an adequate detection of the virus in patients positive for SARS-CoV-2 and was equally sensitive to NPS in TRIzol. We conclude that saliva testing using TRIzol is a recommendable method for diagnosis of SARS-CoV-2 since it has several advantages over currently used saliva tests: it can be done with normal sterile tubes, does not need cold-chain handling, is stable at room temperature, is non-invasive and less costly, making it more accessible for low-income countries. Cheaper saliva testing using TRIzol is especially relevant for low-income countries to optimize diagnosis and help define quarantine durations for families, healthcare workers, schools, and other public workplaces, thus decreasing infections and mortality caused by SARS-CoV-2.

show abstract

“…Many of the comparative studies however, show a reduced sensitivity when true saliva is self-collected by means of devices containing a transport or stabilizing media (Williams et al, 2020 ; Caulley et al, 2021 ; Dogan et al, 2021 ) likely at least in part a result from diluting the saliva sample. Since saliva has been demonstrated to self-preserve the detection of SARS-CoV-2 RNA (Ott et al, 2021 ), circumventing dilution increases the test sensitivity. By removing the need for additives, true saliva collection also permits the testing for SARS-CoV-2 directly in RT-qPCR, allowing labs to bypass non-organic nucleic acid extraction, thus streamlining the molecular analysis and test reporting (Borghi et al, 2021 ; Mahendra et al, 2021 ; Vogels et al, 2021 ).…”

Section: Saliva Collection and Processing Methods Impacts The Test Sensitivitymentioning

confidence: 99%