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

Nurse Vicki Niemi administers a dose of the Pfizer-BioNTech COVID-19 vaccine to Joyce, 88, on Mar. 23, 2020 at the Terrace Sportsplex. All adults in Terrace are now eligible to register for a COVID-19 vaccination. (Ben Bogstie/Terrace Standard)
All adults in Terrace can now register for a COVID-19 vaccine appointment

Community members can register by calling 833-838-2323 or visiting getvaccinated.gov.bc.ca

April 2020 to March 2021 was the second wettest year on record since at least 1969, according to Environment Canada. (Ben Bogstie/Terrace Standard)
VIDEO: Terrace records wettest spell in over a half-century

Terrace saw close to 1,500 millimetres of precipitation between April 2020 and March 2021

Terrace fire department responded to a call from Skeena Saw Mills at the early hours of Friday morning. (Binny Paul/ Terrace Standard)
UPDATE: Fire crews respond to early morning incident at Skeena Sawmills

No injuries were reported as mill workers immediately alerted the fire department after seeing smoke

Terrace Tim Hortons on Keith Ave. experienced a fire during the morning of April 4, 2021. (Ben Bogstie/Terrace Standard)
Nature of Tim Hortons fire made it difficult to detect: Deputy fire chief

Fire likely burned undetected inside a wall, resulting in extensive damage

Restaurant patrons enjoy the weather on a patio in Vancouver, B.C., Monday, April 5, 2021. The province has suspended indoor dining at restaurants and pubs until at least April 19 in B.C. due to a spike in COVID-19 numbers. THE CANADIAN PRESS/Jonathan Hayward
B.C. sets new COVID-19 daily record with 1,293 cases Thursday

New order allows workplace closures when infections found

B.C. Health Minister Adrian Dix and Premier John Horgan describe vaccine rollout at the legislature, March 29, 2021. (B.C. government)
1,262 more COVID-19 infections in B.C. Friday, 9,574 active cases

Province’s mass vaccination reaches one million people

A vehicle that was driven through the wall of a parkade at Uptown Shopping Centre and into the nearby Walmart on April 9 was removed through another hole in the wall later that night. (Photo via Saanich Police Department and Ayush Kakkar)
Vehicle launched into B.C. Walmart removed following rescue of trapped workers

Crews cut new hole in parkade wall to remove vehicle safely

Four members with Divers for Cleaner Lakes and Oceans were out at Cultus Lake on March 28 and 29 hauling trash out of the waters. (Henry Wang)
PHOTOS: Out-of-town divers remove 100s of pounds of trash from Cultus Lake

Members of Divers for Cleaner Lakes and Oceans hauled out 470 pounds of trash over two days

As of Saturday, April 10, people born in 1961 are the latest to be eligible for a COVID-19 vaccine. (Black Press files)
B.C. residents age 60+ can now register to get their COVID-19 vaccine

Vaccine registration is now open to people born in 1961 or earlier

A new saline gargle test, made in B.C., will soon be replacing COVID-19 nasal swab tests for kids. (PHSA screenshot)
Take-home COVID-19 tests available for some B.C. students who fall ill at school

BC Children’s Hospital plans to provide 1,200 kits to Vancouver district schools this April

Ruming Jiang and his dog Chiu Chiu are doing fine following a brush with hypothermia that saw several people work together to get them out of the Fraser River near Langley’s Derby Reach Park on March 25, 2021 (Special to the Advance Times)
Man finds men who rescued him from drowning in B.C.’s Fraser River

A grateful Ruming Jiang says he will thank them again, this time in person when the pandemic ends

Tyson Ginter, 7, is proud of his latest Hot Wheels he recently received by Quesnel RCMP Const. Matt Joyce. (Photo submitted)
B.C. Mountie handing out toy cars to light up children’s faces

‘A lot of times it will be the only interaction they have with the police,’ says Const. Matt Joyce

Chief Public Health Officer Theresa Tam speaks during a technical briefing on the COVID pandemic in Canada, Friday, January 15, 2021 in Ottawa. THE CANADIAN PRESS/Adrian Wyld
Canada’s ICUs see near-record of COVID-19 patients last week as variant cases double

Last week, Canadian hospitals treated an average of 2,500 patients with COVID-19, daily, up 7% from the previous week

University of Victoria rowing coach Barney Williams at the University of Victoria in Victoria, B.C. THE CANADIAN PRESS/Chad Hipolito
UVic, women’s rowing coach deny former athlete’s allegation of verbal abuse

Lily Copeland alleges coach Barney Williams would stand close to her and speak aggressively in the sauna

Most Read