With the onset of influenza season and the potential overlap of influenza and COVID-19 symptoms, there is a need to be able to quickly differentiate between the two viruses to ensure that patients are appropriately managed.
Current COVID-19 diagnostics rely on a PCR test, which can only be undertaken via laboratory analysis and, in some cases, the result is not available for a few days. Now researchers from the UK and Germany have reported their preliminary findings on the use of a device that analyses a breath sample to identify infected patients within 10 minutes. The study makes use of exhaled volatile organic compounds (VOCs) in breath which are subjected to gas chromatography and either mass spectrometry (GC-MS) or ion mobility spectrometry. The researchers based their study on the fact that there are distinct breath biochemistry derangements in respiratory illness and that this could be utilised for the detection of those infected with COVID-19 compared to other viral illnesses. The study recruited participants who presented with respiratory symptoms consistent with COVID-19 and this was confirmed with a PCR test. Participants then exhaled through a disposable tube and a sample of breath withdrawn and placed in the GC-MS.
A total of 98 patients were recruited of whom 79% had confirmed COVID-19. Differentiation of COVID-19 from other conditions was possible in 81.5% of patients. Exhaled breath compounds were attributed to a combination ketosis, impaired gastrointestinal function and inflammatory responses. A distinct panel of compounds including ethanal, octanal, acetone, butanone, methanol, heptanal and one unidentified compound, provided the basis to rule in COVID-19.
The authors reported that the instrument can be easily used in emergency departments for a quick assessment of whether a patient has COVID-19 and that the sampling technique does not pose a risk for clinicians performing the task. They called for further and larger studies to validate these preliminary findings.
Ruszkiewicz DM et al. Diagnosis of COVID-19 by analysis of breath with gas chromatography-ion mobility spectrometry – a feasibility study. EClinical Medicine 2020; https://doi.org/10.1016/j.eclinm.2020.100609