People wear face masks as they walk along a street in Montreal, Sunday, Oct. 18, 2020, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes

People wear face masks as they walk along a street in Montreal, Sunday, Oct. 18, 2020, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes

Canada updates COVID-19 guidelines to include airborne transmission, following U.S., WHO

New information was updated after top doctor recommended triple-layer masks

The Public Health Agency of Canada quietly updated its COVID-19 guidelines this week to include aerosol, or airborne, transmission of the virus.

The move came sometime late Tuesday (Nov. 3) or early Wednesday morning, within 24 hours of the country’s chief medical officer recommendation that masks should be triple-layered, including a filter.

READ MORE: Third layer’s the charm: Canada’s top doctor unveils new face mask recommendations

In a section within Canada’s COVID-19 online information hub titled “How COVID-19 spreads,” the modes of transmission have been updated.

“COVID-19 spreads from an infected person to others through respiratory droplets and aerosols created when an infected person coughs, sneezes, sings, shouts, or talks. The droplets vary in size from large droplets that fall to the ground rapidly (within seconds or minutes) near the infected person, to smaller droplets, sometimes called aerosols, which linger in the air under some circumstances,” the website reads.

The new statement does acknowledge that the “relative infectiousness of droplets of different sizes is not clear.”

The updated information cites outbreaks that occurred in settings with poor ventilation, with the agency said “suggest that infectious aerosols were suspended in the air and that people inhaled the virus.” Those settings include choir practice, fitness classes and restaurants.

“Transmission in these settings may have been facilitated by certain environmental conditions, such as re-circulated air,” the agency’s COVID-19 information reads.

“There is no evidence at this time that the virus is able to transmit over long distances through the air, for example, from room to room through air ducts. It is still unclear how easily the virus spreads through contact with surfaces or objects.”

The prior statements on COVID-19’s mode of transmission included only close contact, meaning “breathing in someone’s respiratory droplets after they cough, sneeze, laugh or sing,” as well as contaminated surfaces and common greetings such as hugs, handshakes and kisses.

Canada’s move came months after other public health agencies began to update their COVID-19 transmission guidelines.

In July, the World Health Organization (WHO) released data suggesting that airborne transmission can spread the novel coronavirus.

“Airborne transmission of the virus can occur in health care settings where specific medical procedures, called aerosol generating procedures, generate very small droplets called aerosols. Some outbreak reports related to indoor crowded spaces have suggested the possibility of aerosol transmission, combined with droplet transmission, for example, during choir practice, in restaurants or in fitness classes.”

In October, the U.S. Centre for Disease Control (US CDC) stated that “COVID-19 can sometimes be spread by airborne transmission,” citing situations where people more than six feet away from others still got infected with the virus.


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

A recently finished $4.3-million taxiway extension at the Victoria International Airport (not pictured) is unusable because of a blind spot. (Black Press Media file photo)
Blind spot leaves Victoria airport’s new $4.3-million taxiway extension unusable

Solution has been put on hold by COVID-19 pandemic, says airport authority

Police say missing man Daniel Fortin, 55, is high-risk. (Courtesy of VicPD)
MISSING: Daniel Fortin, 55, last seen in Victoria March 1

Anyone who sees Fortin asked to call 911

Walkers ascend Mount Douglas Park on Sunday, Feb. 7. Visits to Saanich Parks are up 46 per cent compared to pre-pandemic statistics this time last year. (Darrell Wick Photo)
Oak Bay, Saanich parks peak in popularity during pandemic

Oak Bay spent an extra $5,000 on park toilet paper in 2020

This male Dungeness can safely be harvested after passing muster. An official with Fisheries and Oceans Canada says it is not clear how well locals on the Saanich Peninsula are complying with crabbing regulations, but her comments suggest that any problems might be of a minor nature. (Department of Fisheries and Oceans/Submitted)
Sidney and Sooke record 57 crabbing violations in 2020

While recreational crab fishery has ‘compliance issues,’ no evidence of ‘large scale poaching’

Cleanup happens after an overnight flood Monday damaged areas of the Oaklands Community Centre. (Facebook/Oaklands Community Association)
Greater Victorians offer flood of support to Oaklands Community Centre

Blown hot water tank Monday night leaves staff cleaning up soggy mess

Health Minister Adrian Dix looks on as Dr. Bonnie Henry pauses for a moment as she gives her daily media briefing regarding COVID-19 for British Columbia in Victoria, B.C. THE CANADIAN PRESS/Jonathan Hayward
7 additional deaths and 542 new COVID-19 cases in B.C.

Provincial health officials reported 18 new COVID-19 cases linked to variants of concern

Anyone with information on any of these individuals is asked to call 1-800-222-TIPS (8477) or visit the website victoriacrimestoppers.ca for more information.
Greater Victoria Crime Stoppers wanted list for the week of March 2

Greater Victoria Crime Stoppers is seeking the public’s help in locating the… Continue reading

(Black Press Media file photo)
POLL: How’s your butter?

Recent reports have some Canadians giving a second look to one of… Continue reading

Chelsea Harry was last seen Feb. 21. Photo via Comox Valley RCMP
Vancouver Island RCMP seeking help locating a missing woman

Missing person last seen in Courtenay on Feb. 21

Backcountry skiers are dwarfed by the mountains as they make their way along a mountain ridge near McGillivray Pass Lodge located in the southern Chilcotin Mountains of British Columbia, Tuesday, Jan. 10, 2012. Avalanche Canada has issued a special warning to people who use the backcountry in the mountains of western Alberta and eastern British Columbia. THE CANADIAN PRESS/Jonathan Hayward
Avalanche Canada special warning for mountains in western Alberta, eastern B.C.

Avalanche Canada also says everyone in a backcountry party needs essential rescue gear

Chief Justice Christopher Hinkson (Office of the Chief Justice)
Judge questions whether B.C.’s top doctor appreciated right to religious freedom

Lawyer for province says Dr. Henry has outlined the reasons for her orders publicly

A sample of guns seized at the Pacific Highway border crossing from the U.S. into B.C. in 2014. Guns smuggled from the U.S. are used in criminal activity, often associated with drug gangs. (Canada Border Service Agency)
B.C. moves to seize vehicles transporting illegal firearms

Bill bans sale of imitation or BB guns to young people

The City of Duncan will implement a new pilot project targeting vandalism this spring. (File photo)
Graffiti trouble? Duncan will give you the brush and the paint to remove it

Initiative based on a successful project to protect Port Alberni from unwanted spray paint

BC Housing minister David Eby is concerned that Penticton council’s decision to close a local homeless shelter will result in a “tent city” similar to this one in Everett, Wa. (Olivia Vanni / Black Press file)
‘Disappointed and baffled’ B.C. housing minister warns of tent city in Penticton

Penticton council’s decision to close a local homeless shelter could create tent city, says David Eby

Most Read