Nasopharyngeal versus nasal swabs for detection of SARS-CoV-2: a systematic review

Nasopharyngeal swabbing (NPS) coupled with RT-PCR is the current gold standard for detecting SARS-CoV-2 infections. However, numerous studies have recently demonstrated the advantages of alternative nasal specimen collection approaches over NPS specifically for COVID-19 diagnosis. The present review was conducted according to PRISMA guidelines and summarises the current literature to give a clear overview of nasal specimen collection methods for SARS-CoV-2 detection. Publications investigating NPS and at least one other form of nasal specimen collection in combination with RT-PCR for viral detection in the context of COVID-19 were assessed. We identified 425 articles and ultimately included 18 studies in this systematic review. The suitable publications evaluated different forms of nasal specimen collection, with anterior nasal swabbing (ANS) and midturbinate swabbing (MTS) being the most frequently examined techniques. The analysed studies report sensitivity and specificity results (67.5-96.2% and 97.9-100.0%, respectively) similar to those achieved via NPS, especially in the early stages of disease or when paired with an oropharyngeal swab. Results from these studies suggest that ANS and MTS are suitable alternatives to NPS for COVID-19 testing. Due to their ease of collection, ANS and MTS collection techniques may facilitate broader testing strategies and allow for economization of medical staff.