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

Alberta’s chief medical officer of health Dr. Deena Hinshaw and Premier Jason Kenney say the province would look at adding additional COVID-19 measures in the coming weeks if the virus continues to spread. (Photo by Government of Alberta)
Walk-in COVID-19 vaccination clinic to open in Red Deer

Alberta adds 1,345 new cases of the virus

Public health restrictions on non-essential travel and vacation bookings are being increased in B.C. (B.C. government)
COVID-19: B.C. announces signage along Alberta border to discourage non-essential travel

B.C. extends COVID-19 indoor dining, group fitness ban until May 25

A vial of some of the first 500,000 of the two million AstraZeneca COVID-19 vaccine doses that Canada has secured through a deal with the Serum Institute of India in partnership with Verity Pharma at a facility in Milton, Ont., on Wednesday, March 3, 2021. THE CANADIAN PRESS/Carlos Osorio - POOL
Alberta begins rolling out AstraZeneca COVID vaccine for those aged 40 or older

There are more than 70 pharmacies offering AstraZeneca, including 26 offering walk-in appointments

A child writes in their school notebook during a home schooling session in Cremona, Alta., Monday, March 23, 2020, amid the worldwide COVID-19 pandemic. Thousands of students in Calgary will shift to online learning as of today in a bid to curb rising COVID-19 infection rates in the city. THE CANADIAN PRESS/Jeff McIntosh
Online classes begin for some Alberta students amid rising COVID-19 cases

Alberta currently has the highest rate of active COVID-19 cases in the country

In this image from NASA, NASA’s experimental Mars helicopter Ingenuity lands on the surface of Mars Monday, April 19, 2021. The little 4-pound helicopter rose from the dusty red surface into the thin Martian air Monday, achieving the first powered, controlled flight on another planet. (NASA via AP)
VIDEO: NASA’s Mars helicopter takes flight, 1st for another planet

The $85 million helicopter demo was considered high risk, yet high reward

sign
Alberta Biobord Corp. recently hosted a virtual open house from Stettler

The company plans to develop a fuel pellet and medium density fibre board (MDF) plant near the community

The Rogers logo is photographed in Toronto on Monday, September 30, 2019. THE CANADIAN PRESS/Tijana Martin
Rogers investigating after wireless customers complain of widespread outage

According to Down Detector, problems are being reported in most major Canadian cities

People are shown at a COVID-19 vaccination site in Montreal, Sunday, April 18, 2021, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes
Nothing stopping provinces from offering AstraZeneca vaccine to all adults: Hajdu

Health Canada has licensed the AstraZeneca shot for use in people over the age of 18

Deputy Prime Minister and Minister of Finance Chrystia Freeland responds to a question during Question Period in the House of Commons Tuesday December 8, 2020 in Ottawa. The stage is set for arguably the most important federal budget in recent memory, as the Liberal government prepares to unveil its plan for Canada’s post-pandemic recovery even as a third wave of COVID-19 rages across the country. THE CANADIAN PRESS/Adrian Wyld
Election reticence expected to temper political battle over federal budget

Opposition parties have laid out their own demands in the weeks leading up to the budget

Each spring, the Okanagan Fest-of-Ale is held in Penticton. This year, as a result of the COVID-19 pandemic, the festival will not be held. However, beer is still available. How much do you know about this beverage? (pxfuel.com)
QUIZ: How much do you really know about beer?

Put your knowledge to the test with this short quiz

Pall Bearers carrying the coffin of the Duke of Edinburgh, followed by the Prince of Wales, left and Princess Anne, right, into St George’s Chapel for his funeral, at Windsor Castle, in Windsor, England, Saturday April 17, 2021. (Danny Lawson/Pool via AP)
Trudeau announces $200K donation to Duke of Edinburgh award as Prince Philip laid to rest

A tribute to the late prince’s ‘remarkable life and his selfless service,’ the Prime Minister said Saturday

Most Read