As children prepare to return to school toward the end of this month, concerns about the potential spread of COVID-19 in classrooms will continue to be a hot topic. The CDC recommends regular screening testing of students and staff as part of its Guidance for COVID-19 Prevention in K-12 Schools, making accurate and efficient testing methods for children an important resource as kids get back to learning. Recognizing the need for fast, less expensive and less invasive test options for children, researchers from the Children’s Hospital of Pennsylvania conducted a study that identified six potential biomarkers of COVID-19 in breath samples taken from pediatric patients.
Previous studies have found that metabolites in the breath of adults infected with SARS-CoV-2 differ from those exhaled by non-infected adults, and these differences can be detected by both dogs and sensors. But because the virus tends to affect children differently than it does adults, which could suggest a difference in metabolic response, the researchers focused specifically on pediatric patients, collecting breath samples from 15 children who had tested positive for SARS-CoV-2 and 10 children who had tested negative through RT-PCR. The team analyzed 84 volatile organic compounds (VOCs) in the breath samples through 2D gas chromatography (GCxGC) and time-of-flight mass spectrometry (TOF MS), and found that six VOCs were significantly elevated in infected children compared to non-infected children.
Two of these potential biomarkers — octanal and heptanal — have also been found to be elevated in the breath of adults with COVID-19, but the other four biomarker candidates — nonanal, decane, tridecane and 2-pentyl furan — were unique to child patients. To test if these six VOCs could potentially be used to predict infection, the team analyzed the breath of a different group of 12 infected and 12 non-infected children and found that the biomarker candidates could predict infection with 91% sensitivity and 75% specificity. The results were published in ACS Infectious Diseases.
These preliminary results suggest that breath tests could be used as a low-cost and noninvasive alternative to RT-PCR and antigen tests that use nasopharyngeal swabs. Breath tests could potentially be used for fast, large-scale screenings of K-12 students, and those who test positive could be given more specific RT-PCR tests to confirm the results.