Swish and gargle saliva sampling is a patient-friendly and comparable alternative to nasopharyngeal swabs to detect SARS-CoV-2 in outpatient settings for adults and children

Abstract

Widespread and frequent testing for COVID-19 was an important strategy to identify infected patients to isolate and control the spread of the disease during the pandemic. The nasopharyngeal swab (NPS) global supply chain and access to trained healthcare professionals for standard NPS collection were often compromised. Patient discomfort and limited access challenged health systems to reach large numbers for testing in adult and pediatric populations. Our study revealed that swish and gargle saliva (SGS) was comparable to NPS in detecting SARS-CoV-2 and more patient-friendly than NPS. Patients were more likely to repeat the test with SGS. SGS was amenable to self-collection instead of relying on skilled professionals. This comprehensive evaluation highlights the challenges of comparing the accuracy of new methods to imperfect gold standards and identifies additional patient-centric factors that should be considered when defining such standards. Thus, SGS is an advantageous alternative specimen collection for outpatient en masse testing.

Keywords: SARS-CoV-2 detection; swish and gargle saliva.

Fig 1

Cohort creation and exclusions for the two parts of this study: (i) performance characteristics and (ii) patient experience survey of SGS compared to NPS. We enrolled 252 participants, of whom 90 were children and 162 adults. We excluded 14 pairs of specimens from performance analysis, and coincidently 14 surveys were not answered or received. A total of 238 participants were included in the two parts of the study: rRT-PCR analysis and survey.

Fig 2

Patient experience survey: (A) regarding the agreement on the usability of the sample method, (B) regarding comfort with sampling), and (C) regarding the likelihood of using this sample method again.