The Sensitivity and Costs of Testing for SARS-CoV-2 Infection With Saliva Versus Nasopharyngeal Swabs

The Utility of Mechanical Homogenization in COVID-19 Diagnostic Workflows

“…After months of nasopharyngeal swabbing for COVID-19 diagnostic testing, there was a push to look for equally sensitive testing methodologies which provided a more pleasant patient experience during sample collection [4,6,9]. By improving the patient experience with testing, the hope was to gain public cooperation with viral surveillance efforts [9,13]. The high concentration of SARS-CoV-2 particles found throughout the upper respiratory tract led researchers to begin examining the utility of oral swabs or saliva in the current RT-qPCR testing strategies [13,14].…”

“…By improving the patient experience with testing, the hope was to gain public cooperation with viral surveillance efforts [9,13]. The high concentration of SARS-CoV-2 particles found throughout the upper respiratory tract led researchers to begin examining the utility of oral swabs or saliva in the current RT-qPCR testing strategies [13,14].…”

A novel, automated SARS-CoV-2 saliva PCR test protects a global asymptomatic workforce

“…Interestingly, although higher Ct values are associated with asymptomatic samples and lower infectiveness in viral cultures compared to samples from symptomatic cohorts, these differences are neither consistent nor statistically signi cant [4]. Recent publications have proposed that saliva collection re ects peak infection, predicts COVID-19 outcome and is associated with lower overall cost [5][6][7] compared to nasopharyngeal collection.…”

Is the Patient Infected with SARS-CoV-2?

“…Additionally, in one study that detected SARS-CoV-2 RNA in salivaon February 1, 2021 by guest http://jcm.asm.org/ Downloaded from specimens from asymptomatic persons with 9 matched nasopharyngeal specimens to those samples, 7 nasopharyngeal specimens did not have detectable SARS-CoV-2.All 13 individuals tested positive, however, for COVID-19 on repeat nasopharyngeal swab testing(5). In a recently published meta-analysis of 37 studies with 2372 paired specimens comparing salivary to nasopharyngeal specimens, 13 studies found saliva detected a greater number of infected cases than nasopharyngeal specimens(7). Thus,the detection of infection may vary based on anatomic site of specimen collection as it relates to the duration and time course of infection.…”

“…By fixing a reference standard to one anatomic site to assess new tests, this may increase the risk of determining that a new assay performs worse than it truly does, typically in the direction that the new assay is less specific because it identifies "unconfirmed infections." Less commonly the new assay may be found to be less sensitive if the single reference comparator detects clinically insignificant infections beyond the relevant clinical period of infection.Studies have found that when comparing nasopharyngeal specimens to other anatomic sites (nasal and oral fluid or saliva), infected-persons were missed by nasopharyngeal specimens(5)(6)(7). Additionally, in one study that detected SARS-CoV-2 RNA in salivaon February 1, 2021 by guest http://jcm.asm.org/ Downloaded from specimens from asymptomatic persons with 9 matched nasopharyngeal specimens to those samples, 7 nasopharyngeal specimens did not have detectable SARS-CoV-2.All 13 individuals tested positive, however, for COVID-19 on repeat nasopharyngeal swab testing(5).…”