Doctors call for Canada to adopt airborne transmission protocols for COVID-19

A group of doctors and health-care providers are calling on public health organizations in Canada to acknowledge airborne spread of COVID-19 and adjust restrictions accordingly.

The five doctors published a commentary in the Canadian Medical Association Journal (CMAJ) emphasizing that the spread of SARS-CoV-2 has an airborne component, something that’s been a topic of debate since before the novel coronavirus became a global threat.

“By making a clear, explicit definition of airborne transmission, then it becomes much easier to implement measures that the public understand and will uptake, because this is really about communicating to the public a public health concern,” Dr. Victor Leung, co-author of the commentary, infectious disease physician and a medical microbiologist, told CTVNews.ca in a phone interview on Wednesday.

Airborne transmission means that the SARS-CoV-2 virus is spread through aerosols that linger in the air from people who are talking, breathing, coughing or sneezing. The World Health Organization (WHO), says that the virus is primarily spread through respiratory droplets, which unlike aerosols, drop quickly to the ground and don’t remain in the air.

The medical professionals want public health agencies in Canada to adopt more restrictions in line with this type of transmission, such as better ventilation, the use of N95 and other fitted masks and a move away from the hand-sanitizing, disinfectant-wiping of the early pandemic.

“Places can really look at their cleaning protocols that are excessive. The focus on contacts and surfaces through fomite transmission is not going to be a main driver of transmission in this pandemic,” said Leung.

Other countries have done this and airborne transmission has been acknowledged internationally, and Leung says it’s time to acknowledge that in Canada.

“One of the countries that's been quite a leader in this would be Belgium, where they recently have made very clear instructions for the public in terms of what are things you can do at home and in the community to address airborne transmission,” he said.

Even with COVID-19 infections decreasing in many provinces across the country and vaccination rates rising, it’s still important to focus on good ventilation.

“If we don't get this right now, then we won't be prepared. We'll be dealing with the same controversies, or lack of acknowledgement of transmission when we deal with future respiratory viruses if we don't take into account the information we have now,” he said.

Experts in indoor air quality and ventilation have been calling for better ventilation in indoor spaces for years.

“The connection between ventilation and infectious disease has been very well established and people knew it 200 years ago. There is nothing new about ventilation,” Jeffrey Siegel, professor of civil engineering at the University of Toronto, told CTVNews.ca in a phone interview on Wednesday.

And better ventilation isn’t just beneficial when it comes to respiratory viruses like SARS-CoV-2 or the seasonal flu.

“The benefits are huge,” he said. “In a school you get better cognitive performance, higher test scores, reduced absenteeism, you get better health outcomes, you get higher salaries when the students graduate,” said Siegel.

He said that the cost of improving ventilation in schools, offices and other indoor spaces is worth the benefits that will come with it, along with reduced transmission of infectious diseases, but the issues need to be addressed sooner rather than later.

“Part of the reason we're in such a situation now is that we chose not to make these investments. I described it as a kind of systematic neglect,” he added.

While it’s encouraging to see medical professionals beginning to speak up about the need for airborne transmission protocols, he said they are slow to the uptake.

“It's an airborne disease, there's no question.”

Despite the divide among various professionals, Siegel says there’s really no bad outcome if public health agencies do follow airborne transmission protocols.

“The worst thing that happens if we mitigate an airborne component is that I'm entirely wrong. And there's no benefit in doing so. But that's the absolute worst and all the other things that we know are associated with indoor air quality get better,” he added.

“Anyone who was not suggesting these measures is not taking a particularly complete view of the evidence.”

This isn’t to say that current measures to slow the spread are wrong, masks will still help slow the spread of the virus, as will physical distancing. Siegel has a simple rule to assess the safety of a situation.

“You have to have any two of the following three measures, you either have to be outside wearing masks or physically distanced,” said Siegel.

And to determine if an area has good air quality is equally simple, we can often just tell by if a room feels stuffy or if smells tend to linger. In some situations it’s easy to just ask someone what has been done to improve ventilation -- if they don’t have an answer, Siegel says it’s probably better to be on high alert.

Improving indoor air quality will not only help slow the spread of COVID-19, and ease some of the disparities we are seeing on who is most impacted by the virus, it could also improve disparities in day-to-day life by increasing health benefits among all populations.

“By doing things like improving filtration and ventilation, we should target those environments where we'll improve disparities by doing so. And, I think we have a real opportunity to actually address some of these broader societal issues by addressing indoor air quality.”