Nasopharyngeal versus nasal swabs for COVID-19
Reviewed by Suki Ahluwalia

This systematic review from Austria compares nasopharyngeal swab (NPS) and PCR test to nasal swabs from the other nasal areas with PCR. After finding 425 articles, using PRISMA guidelines 18 were deemed suitable for comparison. Anterior nasal swabs (ANS) and mid turbinate swabs (MTS) were the type commonly studied and reviewed as alternatives. NPS can be difficult, requires training and could result in complications. Patients find it uncomfortable and often cough or sneeze, thereby exposing the collector to possible infection. In comparison, ANS and MTS are more easily performed, can be done by the patient themselves and are better tolerated. The results indicated that the sensitivity and specificity of the more anterior nasal swabs was similar, especially when combined with an oropharyngeal swab. Thus, in areas requiring mass sampling, with lower numbers of trained personnel, this may be a viable alternative. It is also noted that the use of PCR rather than rapid antigen testing (RAT) would be required since only small amounts of viral RNA are required on the swab for detection. RAT is, however, becoming easier, quicker and a more cost-effective option to employ.

Nasopharyngeal versus nasal swabs for detection of SARS-CoV-2: a systematic review.
Gadenstaetter AJ, Mayer CD, Landegger LD.
RHINOLOGY
2021:59(5)410-21.