New COVID Evidence Changes the Way Healthcare is Delivered
by Tim Rowan, Editor
In its August 12 edition, Smithsonian Magazine summarized new research conducted by epidemiologists and published both in The New England Journal of Medicine and a bulletin of the Centers for Disease Control and Prevention. What these scientists have discovered may have an impact on the way in-home clinicians, therapists, and other caregivers practice.
The report reveals findings that not only larger droplets but also microscopic aerosols can transmit the novel coronavirus that causes COVID-19. In fact, aerosols – measuring one-tenth the width of a human hair – can linger suspended in the air for hours. Droplets, which are expelled by sneezing or coughing, are much larger and fall to the ground or other surfaces much more quickly.
“While the difference is literally miniscule,” the report acknowledges, “knowledge of this route of transmission would result in significant changes in how the public can bring an end to the global pandemic. In the near term, it would inform social distancing and mask wearing recommendations from local governments, and in the long term, engineers and architects will need to rethink ventilation and air filtration in the design of everything from schools to cruise ships.”
Aerosols carry pathogens up to dozens of meters under the right conditions. How long a virus can remain airborne depends on the size of the droplet containing it. “That determines everything about how far it can travel, how long it can stay airborne before it falls to the ground,” says Linsey Marr, a professor of civil and environmental engineering at Virginia Tech.
While suspended in the air for hours, some experiments have shown it is possible for the aerosols to remain contagious “for many hours.” says Marr. Different experiments have produced widely varying results, from “more than an hour” in the NEJM report, to “up to 16 hours,” according to CDC researchers.
New discoveries underscore need for familiar prevention activities
- Hand-washing kills aerosols that are picked up while suspended in the air.
- Masks block aerosol sprays to varying degrees depending on the type of mask worn.
- Social distancing remains important because the concentration of aerosols is heaviest near an infected person.
The Smithsonian report concludes that airborne transmission of microscopic aerosols raises the issue of how to protect workers in healthcare settings. When PPE and respirators are in short supply, they should go to healthcare workers first. Surgical masks offer some protection, but it may not be enough for workers who routinely interact with the public. When an in-home care worker enters a patient’s home, they should be aware of the possibility of airborne aerosols and affix their mask well before someone answers the door. The cough that happened an hour before their arrival could be as dangerous as the one that happens while they are in the home.
©2020 by Rowan Consulting Associates, Inc., Colorado Springs, CO. All rights reserved. This article originally appeared in Home Care Technology: The Rowan Report. homecaretechreport.com One copy may be printed for personal use; further reproduction by permission only. editor@homecaretechreport.com
