Clinical validation of 3D-printed nasopharyngeal and oropharyngeal swabs for SARS-CoV-2 RT-PCR

Abstract

Due to limited access to commercially available flocked nasopharyngeal (NP) and oropharyngeal (OP) swabs during the SARS-COV-2 pandemic, we have evaluated the sensitivity of 3D-printed swabs compared to commercial swabs in a clinical setting. We included 35 subjects with known exposure to SARS-CoV-2. Participants were tested with commercial and prototype NP/OP swab pairs 8 and 22 days after exposure. At day 8, the sensitivity of the prototype was 96% for NP-samples (CI 81-99%) and 91% for OP-samples (CI 72-97%). The sensitivity of the commercial swab was 92% for NP-samples (CI 76-98%) and 91% for OP-samples (CI 72-97%). At day 22, the sensitivities of the commercial swab were 100% for NP-samples (CI 82-100%) and OP-samples (CI 77-100%), whereas sensitivity of the prototype was 61% for NP-samples (CI 39-80%) and 54% for OP-samples (CI 29-77%). In conclusion, the prototype might be an alternative to commercial swabs when used early in the course of infection.