ABSTRACT
The diagnostic sensitivity of observed and unobserved self-collected saline gargle samples for the molecular detection of SARS-CoV-2 in adults and school-aged children was evaluated against a reference standard of health care worker collected nasopharyngeal flocked swab. A total of 46 participants had a positive nasopharyngeal swab sample; of these, 10 were in the observed phase and 36 were in the unobserved phase. Only one matching saline gargle sample tested negative and this was in the unobserved phase, giving an overall sensitivity of 98%. Average viral target Ct values were higher in the saline gargle samples. RNaseP Ct values were lower in unobserved collected samples compared to observed collected samples. Unobserved self-collection of saline gargle samples is a promising outpatient testing method for COVID-19 diagnosis. The self-collection method has potential to simplify the diagnostic cycle and facilitate implementation of COVID-19 testing, particularly in settings with limited access to health care workers.
Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Nasopharynx/virology , Saliva/virology , Adult , Child , Child, Preschool , Diagnostic Tests, Routine/methods , Humans , Outpatients , Prospective Studies , SARS-CoV-2/isolation & purification , Sensitivity and SpecificityABSTRACT
We assessed the performance, stability, and user acceptability of swab-independent self-collected saliva and saline mouth rinse/gargle sample types for the molecular detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in adults and school-aged children. Outpatients who had recently been diagnosed with COVID-19 or were presenting with suspected COVID-19 were asked to have a nasopharyngeal (NP) swab collected and provide at least one self-collected sample type. Participants were also asked about sample acceptability using a five-point Likert scale. For those previously diagnosed with COVID-19, all samples underwent real-time PCR testing using a lab-developed assay, and the majority were also tested using an FDA-authorized assay. For those presenting with suspected COVID-19, only those with a positive nasopharyngeal swab sample went on to have other samples tested. Saline mouth rinse/gargle and saliva samples were tested daily at time zero, day 1, and day 2 to assess nucleic acid stability at room temperature. Fifty participants (aged 4 to 71 years) were included; of these, 40 had at least one positive sample and were included in the primary sample yield analysis. Saline mouth rinse/gargle samples had a sensitivity of 98% (39/40), while saliva samples had a sensitivity of 79% (26/33). Both saline mouth rinse/gargle and saliva samples showed stable viral RNA detection after 2 days of room temperature storage. Mouth rinse/gargle samples had the highest (mean, 4.9) and health care worker (HCW)-collected NP swabs had the lowest acceptability scores (mean, 3.1). In conclusion, saline mouth rinse/gargle samples demonstrated higher combined user acceptability ratings and analytical performance than saliva and HCW-collected NP swabs. This sample type is a promising swab-independent option, particularly for outpatient self-collection in adults and school-aged children.