Airborne Transmission

Airborne transmission of covid-19

This article calls for action of public health and government officials to have SARS-CoV-2 categorized as airborne because of the data we’ve seen in large outbreaks as well as the similarities between SARS-CoV and SARS-CoV-2. By not acknowledging that the virus is airborne simply because the detection methods are not in place, it doesn’t mean that it is not airborne when other factors are pointing in that direction. If the virus is airborne then further measures, including extended physical distancing and indoor ventilation, can be made to reduce the spread of the virus.

Transmission and risk factors of COVID-19

This article talks about the generation of aerosols in hospitals during procedures such as bronchoscopy, endotracheal intubation, and administration of nebulizer treatments.

Airborne or droplet precautions for health workers treating COVID-19?

This review examines the transmission routes of COVID-19 in the form of aerosols and droplets and provides evidence that 3-6 feet of distancing may not be enough distance to reduce the transmission from person-to-person. They show that some aerosols can stay in the air up to 3 hours after aerosolization and travel up to 13 feet.

Aerosol emission and super-emission during human speech increase with voice loudness

This research examines the role of speaking and more specifically the loudness of speech as opposed to dramatic droplet and aerosol generating acts such as coughing or sneezing. The authors show that the rate of particle emission during normal speech is positively correlated with the loudness (amplitude) of vocalization.

It Is Time to Address Airborne Transmission of Coronavirus Disease 2019 (COVID-19)

Although hand washing and social distancing are appropriate and necessary to reduce the spread of COVID-19, they are insufficient in that they do not entirely protect from virus-carrying respiratory micro-droplets that are released by infected people during exhalation, talking and coughing. Thus, the authors argue it’s extremely important to treat SARS-CoV-2 as an airborne virus as there is reason to expect it to behave like MERS and Influenza.

High SARS-CoV-2 Attack Rate Following Exposure at a Choir Practice — Skagit County, Washington, March 2020

COVID-19 vulnerability: the potential impact of genetic susceptibility and airborne transmission

This review examines the role of aerosols in the transmission of SARS-CoV-2. From the duration of speaking and breathing to sneezing or coughing, the production of aerosols can stay in the air for minutes to hours and travel distances of more than six feet as compared to droplets containing viral particles. The review also discusses the role of aerosols in indoor or hospital settings as it relates to infectious doses of the virus.

Stability of Middle East respiratory syndrome coronavirus (MERS-CoV) under different environmental conditions

This study compares the aerosol viral viability of H1N1 and MERS-CoV under different environmental conditions. The showed that MERS-CoV remained viable in the environment for a longer period of time than H1N1.

Droplets and Aerosols in the Transmission of SARS-CoV-2

Aerosols produced from breathing or speaking remain in the air longer than droplets because they are not pulled down by gravity. Some people who produce more aerosols are considered “super spreaders”. Aerosol particles can penetrate to the lungs and may be deposited in the alveoli whereas droplets are deposited in the upper respiratory tract (and may be removed through nasal secretions or upwards through the mucociliary escalator to be expelled or swallowed) when inhaled. Aerosols may remain in enclosed spaces or those without proper ventilation for long periods of time.

How can airborne transmission of COVID-19 indoors be minimized?

Although airborne transmission may not be the main route of transmission, third to droplet and direct contact transmission, there is significant enough evidence to warrant the use of engineering controls such as ventilation, air circulation and air cleaning in public buildings, including hospitals, shops, offices, schools, kindergartens, libraries, restaurants, cruise ships, elevators, conference rooms and public transport in addition to other public health measures.

Aerosol and surface contamination of SARS-CoV-2 observed in quarantine and isolation care

Authors examine data from air and surface samples at the University of Nebraska Medical Center from the initial isolation of 13 individuals with COVID-19 to understand the role of viral shedding from isolated individuals and the role of airborne isolation precautions.

Possible indirect transmission of COVID-19 at a squash court, Slovenia, March 2020: case report

Airborne Transmission Route of COVID-19: Why 2 Meters/6 Feet of Inter-Personal Distance Could Not Be Enough

This article provides evidence that the six feet or 2 meter physical distancing measures in place to prevent the transmission from one person to another via close contact may not be enough distance as SARS-CoV-2 has a higher aerosol viability and surface stability as compared to SARS-CoV-1. The authors recommend the continued use of face masks during lockdown and phase one opening in addition to extensive distancing of up to 10m in indoor settings when face masks are not used.

Airborne transmission of SARS-CoV-2: The world should face the reality

SARS-CoV-2 Transmission and the Risk of Aerosol-Generating Procedures

This article addresses the role of aerosol generating procedures on patients with COVID-19 and the prevention of transmission in the hospital and to healthcare workers. To reduce the transmission of COVID-19 as a result of AGPs, they detail what some have instituted including the postponement of non-urgent AGPs and the use of PPE such as N95 and N100 respirators, Powered air purifying respirators, face shields, protective eyewear as well as negative pressure rooms.