ABSTRACT
The COVID-19 pandemic quickly revealed the limitations of existing monitoring and diagnostic capabilities. While rapid antigen tests are not sufficiently reliable, PCR turn-around-time (TAT) typically ranges from hours to days. Standard swab-based tests are also cumbersome and invasive and, worse yet, they detect infection and not transmissibility. A reliable diagnostic test able to discern the infectious phase of COVID-19 could interrupt transmission while limiting isolation requirements. We developed a non-invasive, impaction-based method for capturing aerosols from human breath in one minute of sampling. A proof-of-principle system was used for the detection of viral RNA in breath samples from confirmed positive subjects (=29). A lab setup demonstrated compatibility with on-chip PCR, reducing the TAT to 15-20 minutes. Positive percentage agreement (PPA) between a breath- and nasopharyngeal PCR is 75% overall and 92% in the first 7 days of infection, after which the breath does not contain measurable virus anymore. Breath positivity corresponds to the infectious window. No false positives were noted. Diagnostic accuracy is superior to nasopharyngeal rapid antigen tests. This novel concept of aerosol capturing combined with ultra-fast PCR is proven to be effective to detect SARS-CoV-2 in breath, rivalling the standard nasopharyngeal PCR tests. Combined with a TAT on par with rapid antigen tests, the technology has the potential to become a standard test in the coming years, for COVID-19 or other infectious diseases. A validation study with an advanced setup is currently ongoing, first data should be available during the presentation.