
Photo Credit PHIL
This makes a huge difference – particularly for healthcare workers – because it dictates the level of PPEs that HCWs should be wearing when in close contact with a patient.
Scientists `Airborne’ Letter To WHO & Another SARS-CoV-2 Ventilation Dispersal StudyEID Journal: Persistence of SARS-CoV-2 in Aerosol Suspensions
J. Infect. Dis.: Airborne or Droplet Precautions For COVID-19?
Rapid Expert Consultation on the Possibility of Bioaerosol Spread of SARS-CoV-2 for the COVID-19 Pandemic (April 1, 2020) – Nat. Academy Sci.
Ask such patients to wear a face mask as soon as they are identified. Conduct patient evaluation in a private room with the door closed, ideally an airborne infection isolation room, if available. Personnel entering the room should use standard precautions, contact precautions, and airborne precautions, and use eye protection (goggles or a face shield).
Below are changes to the guidance as of July 15, 2020:
- Added language that protective eyewear (e.g., safety glasses, trauma glasses) with gaps between glasses and the face likely do not protect eyes from all splashes and sprays.
And to be fair, many of these past studies have used artificial aerosolization techniques – not direct real time measurements from patients – and while RT-PCR testing has shown evidence of SARS-CoV-2 genetic material in aerosols and on fomites some distance from patients, the virus had not been proven to remain infectious.
Not only were these researchers able capture aerosolized virus particles in patient’s room air, they were able to demonstrate viability, by growing them in cell cultures.
The Infectious Nature of Patient-Generated SARS-CoV-2 Aerosol
Joshua L Santarpia, Vicki L Herrera, Danielle N Rivera, Shanna Ratnesar-Shumate, St. Patrick Reid, Paul W Denton, Jacob W.S. Martens, Ying Fang, Nicholas Conoan, Michael V Callahan, James V Lawler, David M Brett-Major, John J LoweThis article is a preprint and has not been certified by peer reviewAbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission causing coronavirus disease 2019 (COVID-19) may occur through multiple routes.
We collected aerosol samples around six patients admitted into mixed acuity wards in April of 2020 to identify the risk of airborne SARS-CoV-2. Measurements were made to characterize the size distribution of aerosol particles, and size-fractionated, aerosol samples were collected to assess the presence of infectious virus in particles sizes of >4.1 μm, 1-4 μm, and <1 μm in the patient environment. Samples were analyzed by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR), cell culture, western blot, and transmission electron microscopy (TEM).
SARS-CoV-2 RNA was detected in all six rooms in all particle size fractions (>4.1 μm, 1-4 μm, and <1 μm). Increases in viral RNA during cell culture of the virus from recovered aerosol samples demonstrated the presence of infectious, replicating virions in three <1 μm aerosol samples (P<0.05). Viral replication of aerosol was also observed in the 1-4 μm stage but did not reach statistical significance (0.05<P<0.10). Western blot and TEM analysis of these samples also showed evidence of viral proteins and intact virions.
The infectious nature of aerosol collected in this study further suggests that airborne transmission of COVID-19 is possible, and that aerosol prevention measures are necessary to effectively stem the spread of SARS-CoV-2.
ConclusionOur results demonstrate that SARS-CoV-2 RNA exists in respired aerosols less than 5 µm in diameter; that aerosols containing SARS-CoV-2 RNA exist in particle modes that are produced during respiration, vocalization, and coughing; and that some fraction of the RNA-containing aerosols contain infectious virions (Table S7).
This study supports the use of efficient respiratory protection and airborne isolation precautions to protect from exposure to fine SARS-CoV-2 aerosol when interacting with infected individuals, regardless of symptoms or medical procedure being performed. Given the prospect of continued widespread circulation of COVID-19, and recent work highlighting the relative importance of airborne transmission of COVID-195 , it is crucial that evidenced-based IPC practices are promoted and implemented to limit the transmission of SARS-CoV-2 in healthcare, community and industry settings.
Given the infectious nature of aerosol collected in this study, taken with the other lines of evidence presented, further suggests that airborne transmission of COVID-19 is possible, and that aerosol prevention measures should be implemented to effectively stem the spread of SARS-CoV-2, particularly in crowded settings.
All of this has implications, not only for Health Care Workers and their PPEs, but for the rest of us as well.
It supports that notion that crowded indoor venues represent a higher risk environment, raises additional questions over the potential spread of the virus by ventilation systems, and suggests that the 2-meter separation rule may not always be adequate.


You must be logged in to post a comment.