Sputum samples were most likely to test positive by RT-PCR, regardless of the clinical severity of disease. Detection profile of SARS-CoV-2 using RT-PCR in different types of clinical specimens: A systematic review and meta-analysis ( Bwire, July 2020 ). 8136 pooled clinical specimens analyzed to detect SARS-CoV-2; most were nasopharyngeal …
https://www.idsociety.org/covid-19-real-time-learning-network/diagnostics/RT-pcr-testing/