Sample collection and transport strategies to enhance yield, accessibility, and biosafety of COVID-19 RT-PCR testing.
Introduction. Non-invasive sample collection and viral sterilizing buffers have independently enabled workflows for more widespread COVID-19 testing by reverse-transcriptase polymerase chain reaction (RT-PCR).Gap statement. The combined use of sterilizing buffers across non-invasive sample types to optimize sensitive, accessible, and biosafe sampling methods has not been directly and systematically compared.Aim. We aimed to evaluate diagnostic yield across different non-invasive samples with standard viral transport media (VTM) versus a sterilizing buffer eNAT- (Copan diagnostics Murrieta, CA) in a point-of-care diagnostic assay system.Methods. We prospectively collected 84 sets of nasal swabs, oral swabs, and saliva, from 52 COVID-19 RT-PCR-confirmed patients, and nasopharyngeal (NP) swabs from 37 patients. Nasal swabs, oral swabs, and saliva were placed in either VTM or eNAT, prior to testing with the Xpert Xpress SARS-CoV-2 (Xpert). The sensitivity of each sampling strategy was compared using a composite positive standard.Results. Swab specimens collected in eNAT showed an overall superior sensitivity compared to swabs in VTM (70 % vs 57 %, P=0.0022). Direct saliva 90.5 %, (95 % CI: 82 %, 95 %), followed by NP swabs in VTM and saliva in eNAT, was significantly more sensitive than nasal swabs in VTM (50 %, P<0.001) or eNAT (67.8 %, P=0.0012) and oral swabs in VTM (50 %, P<0.0001) or eNAT (58 %, P<0.0001). Saliva and use of eNAT buffer each increased detection of SARS-CoV-2 with the Xpert; however, no single sample matrix identified all positive cases.Conclusion. Saliva and eNAT sterilizing buffer can enhance safe and sensitive detection of COVID-19 using point-of-care GeneXpert instruments.
['Banada|Padmapriya|P|', 'Elson|David|D|', 'Daivaa|Naranjargal|N|', 'Park|Claire|C|', 'Desind|Samuel|S|', 'Montalvan|Ibsen|I|', 'Kwiatkowski|Robert|R|', 'Chakravorty|Soumitesh|S|', 'Alland|David|D|', 'Xie|Yingda L|YL|']
D000328:Adult D000368:Aged D000086382:COVID-19 D000087123:COVID-19 Nucleic Acid Testing D003264:Containment of Biohazards D003470:Culture Media D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009055:Mouth D009305:Nasopharynx D009666:Nose D000067716:Point-of-Care Testing D000086402:SARS-CoV-2 D012463:Saliva D012680:Sensitivity and Specificity D013048:Specimen Handling
Nasal Oral Saliva eNAT Inactivation