ABSTRACT
Background
Detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by naso/oropharyngeal swabbing may expose health-care workers to the virus and is technically challenging. The Salivette® is an alternative saliva-collection device with an oral cotton swab containing citric acid to stimulate saliva production, which may have an unpleasant taste. We present a pilot study comparing the Salivette® Cortisol (SC), which uses a synthetic swab without citric acid, against oropharyngeal swabbing for the detection of SARS-CoV-2 by reverse transcription quantitative polymerase chain reaction (RT-qPCR).
Research design and methods
Symptomatic SARS-CoV-2-positive patients were sampled at various timepoints. The number of patients positive/negative for SARS-CoV-2 in oropharyngeal swab and SC samples and the percentage of patients testing true positive/true negative for SARS-CoV-2 from SC samples were determined. Positivity was defined by RT-qPCR amplification of 2/3 target SARS-CoV-2 N, ORF1, and S gene sequences.
Results
SC demonstrated 100% specificity, 52.2% sensitivity, and positive correlation with oropharyngeal swabbing for the detection of the SARS-CoV-2 S gene. In later-stage disease, lower viral load was observed in SC samples compared with oropharyngeal swabs.
Conclusions
The SC may be an alternative for SARS-CoV-2 detection where naso/oropharyngeal swabbing is not feasible/available. This technique also confirms observations that the detection of SARS-CoV-2 in the upper airway may vary due to viral load over the disease course.
Trial registration
NCT04599959
Declaration of interests
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contributions
J Zúñiga was the Principal Investigator for this study. P Moroni-Zentgraf, C Eschenfelder, C Keller and J Zúñiga conceptualized the work entailed in this manuscript. P Moroni-Zentgraf, C Eschenfelder, C Keller, R Sigmund and H Walter Mueller designed the methodology for the study. J Zúñiga provisioned the resources and study materials for this study. J Zúñiga was responsible for data curation. Formal analyses of the data were undertaken by R Sigmund, H Walter Mueller and J Zúñiga. H Walter Mueller performed visualization and presentation of the data. Data validation, including reproducibility of research outputs, was performed by the Boehringer Ingelheim programming team. All authors were involved in the writing, critical reviewing, revision and editing of the manuscript. P Moroni-Zentgraf, C Eschenfelder, C Keller, R Sigmund, H Walter Mueller and J Zúñiga supervised the project and were responsible for all research activity-related planning and execution. Project administration, including management and co-ordination of research activities, was handled by P Moroni-Zentgraf, C Keller and C Eschenfelder.
Acknowledgments
The authors would like to thank the study participants, investigators and coordinators, Bioscientia and the Occupational Healthcare Service Team at Boehringer Ingelheim. Medical writing assistance, in the form of the preparation and revision of the manuscript, was supported financially by Boehringer Ingelheim and provided by Lee Kempster, PhD at MediTech Media (London, UK), under the authors’ conceptual direction and based on feedback from the authors.