Expert Rev Mol Diagn. 2023 Sep 19. doi: 10.1080/14737159.2023.2260308. Online ahead of print.
BACKGROUND: Detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by naso/oropharyngeal swabbing may expose healthcare 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 detection of SARS-CoV-2 by 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 percentage testing true positive/true negative for SARS-CoV-2 from SC samples was 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 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 detection of SARS-CoV-2 in the upper airway may vary due to viral load over the disease course.
TRIAL REGISTRATION: NCT04599959.