Analysis of Factors Causing False-Negative Real-Time Polymerase Chain Reaction Results in Oropharyngeal and Nasopharyngeal Swabs of Patients With COVID-19.

Patient- and/or sample-related factors can affect RT-PCR results of possible COVID-19 cases. The presence of these factors can easily be determined in cases with high clinical suspicion and negative RT-PCR results. The presence of ageusia, anosmia, early sampling (<7days), and appropriate collection of swabs decrease false-negative RT-PCR results.