Detection of COVID-19 through breath sample analysis with an electronic nose - 20/03/24

The rapid detection of coronavirus disease 2019 (COVID-19) is a fundamental part of the fight against this pandemic. The nose swab PCR test for COVID-19 is an accurate, reliable, reference test for detecting infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, this “gold standard” can be usefully complemented by methods such as rapid antigen detection tests (RADTs) for the faster and/or cheaper detection of infection. However, non-invasive methods could also be invaluable in busy areas; for example, COVID-19's volatile organic compound signature can be characterized with electronic noses (e-noses).

Here, we evaluated an e-nose (a quartz microbalance sensor array) in the detection of COVID-19 status in expired breath samples collected in a bag. The samples were obtained from (i) people suffering from mild-to-severe COVID-19 and (ii) PCR-negative controls (including healthy people) recruited at the emergency department.

The exhaled breath was collected from 289 subjects: 65 hospitalized patients with high-risk COVID-19, 108 patients with mild-to-severe COVID recruited at the emergency department, and 116 PCR-negative controls (60 patients recruited at the emergency department, and 56 healthy subjects). The e-nose distinguished between patients with moderate-to-severe COVID and healthy individuals and between patients with ongoing, severe COVID and those having recovered from COVID with diagnostic sensitivity, specificity and accuracy values that were generally close to or over 90%. Concomitant provision of oxygen did not alter the e-nose's performance.

Our results emphasized the value of an e-nose for COVID-19 screening and indicate that studies of an “e-nose+confirmatory RADT” screening strategy now warrants investigation.