Aerosol measurement identifies SARS-CoV 2 PCR positive adults compared with healthy controls

• Published in: Environmental research Vol. 216; no. Pt 1; p. 114417
• Main Authors: Gutmann, Desireé, Scheuch, Gerhard, Lehmkühler, Timon, Herrlich, Laura-Sabine, Landeis, Anton, Hutter, Martin, Stephan, Christoph, Vehreschild, Maria, Khodamoradi, Yascha, Gossmann, Ann-Kathrin, King, Florian, Weis, Frederik, Weiss, Maximilian, Rabenau, Holger F., Graf, Juergen, Donath, Helena, Schubert, Ralf, Zielen, Stefan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.01.2023; Published by Elsevier Inc
• Subjects: Acute respiratory tract infection; Adult; Aerosols; body mass index; cohort studies; COVID-19; COVID-19 - diagnosis; Germany; hospitals; Humans; lungs; PCR; Polymerase Chain Reaction; Prospective Studies; Respiratory Aerosols and Droplets; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Severe acute respiratory syndrome-related coronavirus; shear stress; Super spreader; Germany; COVID-19; Super spreader; Aerosols; Acute respiratory tract infection; PCR
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2022.114417

SARS-CoV-2 is spread primarily through droplets and aerosols. Exhaled aerosols are generated in the upper airways through shear stress and in the lung periphery by ‘reopening of collapsed airways’. Aerosol measuring may detect highly contagious individuals (“super spreaders or super-emitters”) and discriminate between SARS-CoV-2 infected and non-infected individuals. This is the first study comparing exhaled aerosols in SARS-CoV-2 infected individuals and healthy controls. A prospective observational cohort study in 288 adults, comprising 64 patients testing positive by SARS CoV-2 PCR before enrollment, and 224 healthy adults testing negative (matched control sample) at the University Hospital Frankfurt, Germany, from February to June 2021. Study objective was to evaluate the concentration of exhaled aerosols during physiologic breathing in SARS-CoV-2 PCR-positive and -negative subjects. Secondary outcome measures included correlation of aerosol concentration to SARS-CoV-2 PCR results, change in aerosol concentration due to confounders, and correlation between clinical symptoms and aerosol. There was a highly significant difference in respiratory aerosol concentrations between SARS-CoV-2 PCR-positive (median 1490.5/L) and -negative subjects (median 252.0/L; p < 0.0001). There were no significant differences due to age, sex, smoking status, or body mass index. ROC analysis showed an AUC of 0.8918. Measurements of respiratory aerosols were significantly elevated in SARS-CoV-2 positive individuals, which helps to understand the spread and course of respiratory viral infections, as well as the detection of highly infectious individuals. •SARS-CoV-2 is primarily spread through exhaled aerosols generated in the airways.•SARS-CoV-2 positive subjects exhaled significantly more aerosols than controls.•Exhaled aerosol measurements correlate with disease severity.•Measurement of exhaled particle counts identify highly contagious individuals.•Exhaled aerosols help to choose mitigation strategies to contain the viral spread.