Inclusion Criteria:  General:  Male or female subject aged 18 years and above Subject is able and willing to provide informed consent  Subject is able to complete the breath test.  Arm A:  Requiring a diagnostic or screening RT-PCR test for COVID-19.  Arm B:  Positive to COVID-19 in RT-PCR test performed up to 48 hours before screening.  Exclusion Criteria:  Male of female subject under the age of 18. Subject is unable to provide and informed consent, for any reason.