Infection preventionists need to stress the importance of aerosolization with increased recommendations for N-95 masks and we all need to realize that a prerequisite of reopening a business, school or public venue should be safe ventilation.
New estimates released this week that uses excess death data collected by the Institute of Health Metrics and Evaluation (IHME) at the University of Washington, and says that 905,285 people in the United States died from COVID-19, not the 574,043 deaths that have officially been reported.The toll of this pandemic in both deaths and chronic long-hauler disability makes it imperative that we invest the needed resources to stop this virus.
Infection preventionists need to stress the importance of aerosolization with increased recommendations for N-95 masks and we all need to realize that a prerequisite of reopening a business, school or public venue should be safe ventilation with an increased number of complete air exchanges along with air sanitization.
The new death estimates come as the Centers for Disease Control and Prevention (CDC) yesterday took a major step by clearly articulating three principal modes for viral spread.
“The principal mode by which people are infected with SARS-CoV-2 (the virus that causes COVID-19) is through exposure to respiratory fluids carrying infectious virus. Exposure occurs in three principal ways: (1) inhalation of very fine respiratory droplets and aerosol particles, (2) deposition of respiratory droplets and particles on exposed mucous membranes in the mouth, nose, or eye by direct splashes and sprays, and (3) touching mucous membranes with hands that have been soiled either directly by virus-containing respiratory fluids or indirectly by touching surfaces with virus on them.”
There are 4 take-home messages:
Aerosolization of SARS-CoV-2 (the virus which causes COVID-19) is one of its major mechanisms of spread. Infection Control Today® first covered this topic on April 3, 2020 with the virus spreading rapidly throughout a church choir in Washington State. Most recently, on March 4, 2021, we again stressed the importance of aerosolization of SARS-CoV-2 in indoor settings and how this is a major driver of the pandemic. This position is supported by a growing number of scientists. The science behind it is sound.
The Proceedings of the National Academy of Sciences reported that, despite being a small droplet, particles up to 100 micros can aerosolize. Viruses in these smaller droplets can survive and float in the air with a half-life of 1.1 hours. And that “These aerosols and droplets are produced by breathing, talking, and coughing, with talking associated with aerosols and the fast-settling droplets with coughing.”
Because of the above, on March 4, 2021, we advised that “the CDC needs to articulate firm and harmonized advisements which are consistent across all materials, recommendations and webpages.”
The mindset that you are safe, if you wear a cotton mask and are 6 feet away from someone needs to change. It is not true. SARS-CoV-2 is airborne. And as the third principal mechanism of spread necessitates, we still need to be vigilant regarding contaminated surfaces and wash our hands.
The small viral particle size of 0.1 micron could potentially defeat an N95 mask. However, within as they enter the mask, they are blocked and captured with electrostatic forces and Brownian motion which causes them to collide with and stick to the mask’s fibers. Thus, it is best to wear an N95 mask. A multiple layered, well-fitted cotton or cloth mask will also afford some protection. Cloth masks are felt to be key in providing good community health and driving the SARS-C0V-2 R0 (pronounced R naught) to less than one; slowing, then stopping the spread of the virus. However, cloth masks may not provide adequate protection for individuals in a high-risk setting. I still do eat indoors at restaurants. As I have stated: “Nowhere is safe in poorly ventilated buildings.”
The CDC’s website also states that spread can be mitigated by “… physical distancing, community use of well-fitting masks (e.g., barrier face coverings, procedure/surgical masks), adequate ventilation, and avoidance of crowded indoor spaces. These methods will reduce transmission both from inhalation of virus and deposition of virus on exposed mucous membranes. Transmission through soiled hands and surfaces can be prevented by practicing good hand hygiene and by environmental cleaning.”