Understanding Potential Airborne Transmission and the Protective Value of Type II Surgical Masks in SARS-CoV-2
Condition: SARS-CoV-2
Study type: Observational

Summary: 
      Modes of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and
      specifically the proportion of airborne transmission in this infection is unknown. In the
      aeroCOVID study, a highly efficient bioaerosol and droplet sampling dummy is used to emulate
      a susceptible healthcare worker (HCW) and to perform patient proximity sampling. The dummy
      will measure the dummy-inhaled dose of SARS-CoV-2 in two particle size fractions in a
      standardized interaction with hospitalized coronavirus disease 2019 (COVID-19) patients. All
      measurements are performed in a masked and unmasked dummy setup in parallel, in order to gain
      further information on the protection of type II masks against the respective particle size
      exposure.
    

Detailed description: 
      Modes of interpersonal transmission in SARS-CoV-2 are to date only incompletely understood
      and require further investigation in order to define best preventive measures. Although a
      dichotomization of inhaled particles by particle size is an oversimplification and a large
      particle size does not exclude shortterm airborne behavior, the suspension time of virus
      containing particles and the probability of particles to accumulate in room air is primarily
      defined by particle size distribution. Particles with a size below 10 µm have a high
      probability of accumulation due to their mean suspension time of minutes to hours.

      The study aims to measure the total amount of virus copies per particle size fraction inhaled
      by a highly efficient sampling dummy emulating a susceptible HCW in a standardized
      interaction with hospitalized COVID-19 patients. As a secondary endpoint, the proportion of
      culturable virus in each setup is measured as well.

      Sampling is done in using two parallel bioaerosol and droplet sampling dummies - one type II
      masked and one with an unmasked dummy head as inlet - in order to gain additional information
      on the protective effect of type II surgical masks in a real-life exhaled particle size
      distribution in hospitalized COVID patients. The sampling dummy consists of a real size face
      relief connected to an 60° inlet cone, a cyclone for collection of particles >10 µm and a
      laminar flow water-based condensation bioaerosol collector for particle collection below 10
      µm particle size.

      After patient proximity sampling, a nasopharyngeal swab for SARS-CoV-2 polymerase chain
      reaction (PCR) assay is performed. Relevant indoor climate parameters like temperature,
      humidity and carbon dioxide (CO2) as well as room characteristics as air change rate are
      recorded as well.
    

Observational model: Other
Time perspective: Other
Sampling method: Non-Probability Sample
Study population: 
        The study is performed with hospitalized COVID-19 patients at Inselspital, Bern University
        hospital. The study site hospital is a tertiary university hospital treating COVID-19
        patients on normal hospital wards as well as in the intensive care unit.
      
Biospecimen description: 
      Nasopharyngeal swab
    
Keywords: Airborne transmission; Aerosol transmission; Surgical masks