In a study published in Influenza and Other Respiratory Viruses, researchers were able to detect SARS-CoV-2 viral RNA in droplets from the exhaled breaths and coughs of COVID patients.
COVID is assumed to be transmitted mainly by respiratory droplets. However, probable aerosol transmission has been reported to occur under certain conditions. The researchers sought to address the lack of information on viral load in exhaled breath samples,as well as the size and concentration of exhaled endogenously generated droplets in relation to viral load. Additionally, the relationship between the viral load in upper airway diagnostic samples and aerosol samples needed to diagnose.
For the study, researchers analysed exhalations by two different methods during 20 normal breaths, 10 airway opening breaths (which involves deep inhalation followed by relaxed exhalation), and 3 coughs.
PCR detection of SARS-CoV-2 RNA in aerosols was possible in 10 out of 25 participants. Viral RNA presence in aerosol was mainly detected in cough samples (8 samples), but also in normal breaths (4 samples) and in airway opening breaths (3 samples).
“Our data confirm findings from other researchers that SARS-CoV-2 can be detected in aerosol particles < 5µm and highlight the small amount of exhaled aerosol needed for detection. Of specific interest were findings from the airway opening maneuver, which is thought to generate particles mainly from the small airways,” said lead author Emilia Viklund, PhD student at the University of Gothenburg, in Sweden. “COVID causes a lot of damage in this region, and it would be of great interest to further explore the amount of exhaled virus and the course of disease, as well as the infectious potential of exhaled virus.”
Source: Wiley
