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NON-SEROLOGIC TEST FOR COVID-19: HOW TO MANAGE?
  • Sara Torretta et al.
Sara Torretta et al.
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Abstract

Background: Diagnosis of Severe Acute Respiratory Coranavirus-2 (SARS-CoV-2) infection is currently based on Real-Time PCR (RT-PCR) performed on either nasopharyngeal (NPS) or oropharyngeal (OPS) swabs; saliva specimen collection can be used, too. Diagnostic accuracy of these procedures is suboptimal, and some procedural mistakes may account for it.
Methods and results: The video shows how to properly collect secretions from the upper airways for non-serologic diagnosis of COVID-19 by nasopharyngeal swab (NPS), oropharyngeal swab (OPS), and deep saliva collection after throat-cleaning manoeuvre, all performed under videoendoscopic view by a trained ENT examiner.
Conclusions: We recommend to perform NPS after elevation of the tip of the nose in order to reduce the risk of contamination from the nasal vestible, and to let it flow over the floor of the nasal cavity in parallel to the hard palate in order to reach the nasopharynx. Then the tip of the swab should be left in place for few seconds, and then rotated in order to achieve the largest absorption of nasopharyngeal secretions. Regards OPS, gentle anterior tongue depression should be used to avoid swab contamination from the oral cavity during collection of secretions from the posterior pharyngeal wall. These procedural tricks would enhance diagnostic reliability.