Respiratory Aerosols in Patients With COVID-19 and Healthy Controls

The proposed study will investigate respiratory aerosols in SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona Virus 2) positive and negative children and adults with the Resp-Aer-Meter (Palas GmbH). For this purpose, first, the measurement of respiratory aerosols (particle sizes and concentration) with the Resp-Aer-Meter will be established. Thereafter, a comparison between polymerase chain reaction (PCR) SARS-CoV-2 positive and negative participants (children and adults) will be conducted. In addition to the measurement of aerosols, the clinical symptoms, lung function (FEV1) and laboratory inflammatory markers will be analyzed.

Corona virus disease 2019 (COVID-19) is a viral illness caused by SARS-CoV-2. Current research suggests that the SARS-CoV-2 infection is primarily spread through droplets and aerosols. As per current literature, the spread through asymptomatic carriers, as well as highly contagious carriers ('super spreader') play an important role in the infectiousness of the virus. It is currently unclear, if the contagiousness of children differs from adults. In the proposed investigation, measurement of the particle size and concentration in respiratory aerosols will be conducted via the Resp-Aer-Meter (Palas GmbH). First step will be to establish the measurements with this new device. Thereafter, a comparison between PCR SARS-CoV-2 positive and negative participants, as well as between children and adults, will be conducted. In addition to the measurement of aerosols, the clinical symptoms suggestive of COVID-19, lung function (FEV1) and laboratory inflammatory markers, if available, will be analyzed.

Healthy adults with recent negative SARS-CoV-2 PCR test (nasopharyngeal swab). Will consist of parents of participating children and other healthy volunteers.

Adults with recent positive SARS-CoV-2 PCR test (nasopharyngeal swab). Will consist of asymptomatic parents that are in the hospital with their children and symptomatic adults that are admitted to the infectious disease ward.

Children with recent negative SARS-CoV-2 PCR test (nasopharyngeal swab). Will consist of children admitted to the Children's Hospital or presenting for planned diagnostic testing or follow up.

Children with recent positive SARS-CoV-2 PCR test (nasopharyngeal swab). Will consist of asymptomatic children that are admitted to the Children's Hospital for reasons other than COVID-19 and symptomatic children.

Measurement of respiratory aerosols (particle size and concentration) through breathing into the Resp-Aer-Meter for 3-6 Minutes and comparison between groups.

Comparison of peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) between groups.

Qualitative and quantitative virus PCR of respiratory secretions in patients with high aerosol concentrations

Comparison between result of aerosol measurement and quantitative and qualitative virus PCR of respiratory secretions that are caught in a filter in which the patient breathes for 10 minutes. Test will be conducted on patients with high aerosol concentrations (>5000/L).

Distinction between PCR SARS-CoV-2 positive and negative participants via aerosol measurement. Especially participants with high aerosol concentrations should be detected.

Characterization of longitudinal change in aerosol concentration over the course of illness in PCR SARS-CoV-2 positive patients.

Qualitative and quantitative virus detection in respiratory secretions of patients with high aerosol concentrations.

Quantitative and qualitative virus PCR measurements of respiratory secretions in participants with aerosol concentrations > 5000/L.

Investigation of change in aerosol concentration due to confounders, such as age, sex, other viral illness, lung function, height, weight, BMI and smoking status.

Correlation between clinical symptoms and results of aerosol measurement in PCR SARS-CoV-2 positive participants. Determination if more symptoms lead to higher aerosol concentrations.

Inclusion Criteria: Age 6 years or older SARS-CoV-2 PCR testing within the last 3 days Ability to capture extend and consequences of the study Written informed consent of patient and, if applicable, of caregiver Exclusion Criteria: Age under 6 years Inability to participate in aerosol measurement Inability to participate in Spirometry Inability to capture extend and consequences of the study Only for arm 1 (PCR SARS-CoV-2 negative adults): chronic disease with immunosuppressive therapy

The data will be available after the end of study and successful publication of the results (anticipated June 2022) for 10 years

Gutmann D, Donath H, Herrlich L, Lehmkuhler T, Landeis A, Ume ER, Hutter M, Gossmann AK, Weis F, Weiss M, Rabenau HF, Zielen S. Exhaled Aerosols in SARS-CoV-2 Polymerase Chain Reaction-Positive Children and Age-Matched-Negative Controls. Front Pediatr. 2022 Jul 18;10:941785. doi: 10.3389/fped.2022.941785. eCollection 2022.