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Why Canadian health leaders are downplaying concerns about airborne COVID-19 microdroplets – CTV News

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TORONTO —
Some of Canada’s top provincial doctors are downplaying new concerns from hundreds of scientists that physical distancing and frequent handwashing are not enough to fully protect against airborne transmission of the novel coronavirus.

In an open letter to the World Health Organization (WHO), 239 scientists in 32 countries argued that particles smaller than what has previously been reported can carry SARS-CoV-2, the virus that causes COVID-19, posing more of a danger than public health officials have been warning against.

However, in a news conference on Monday, B.C. provincial health officer Dr. Bonnie Henry said the letter is controversial.

“When you’re in close contact with someone… particularly if you’re indoors where there’s poor ventilation and you’re coughing or sneezing or singing or hugging or dancing, those are the situations where you’re much more likely to transmit this virus, regardless of what size particle that you’re breathing in,” Henry said.

Henry said that microdroplets of airborne viruses such as measles and smallpox can float in the air for hours, move down hallways and even through ventilation systems, but the novel coronavirus appears to spread predominantly through larger droplets, according to Henry. She said that transmission of the virus requires more moisture and closer contact between people.

“We know that there is a gradation of how droplets come out when somebody coughs or sneezes or talks, and it is a smaller ones that can be breathed deep into the lungs, and it’s the larger ones that are often deposited up in the back of the throat or in the upper part of the lungs,” Henry explained.

“But we know that the amount of … moisture the virus needs to stay alive is a bit more for some of these viruses like influenza and COVID,” she added.

Since the start of the pandemic the WHO has maintained that the droplets that carry SARS-CoV-2 are spread through actions including coughing, sneezing and speaking, and recommends that people keep a one-metre distance from others. Many countries, including Canada, have gone farther, recommending a physical distance of two metres.

The WHO said Tuesday that it has been in constant discussions with many of the letter’s signatories since April and is looking into the possible role of airborne transmission of COVID-19.

The organization said it has looked at a number of different ways the virus could be contracted including through inanimate objects, fecal-oral transmission, droplet, aerosol, mother-to-child and animal-to-human to “try to consolidate the growing knowledge around transmission.” It will release a scientific brief in the coming days on its findings.

“This is a respiratory pathogen and so it is important that what we know fits into the guidance that we have, which is why a comprehensive package of interventions are required to be able to stop transmission,” Dr. Maria Van Kerkhove, head of the WHO’s emerging diseases and zoonosis unit, said in a press conference.

Henry said the novel coronavirus is “not transmitted long distances in the air column,” but a previous American study found signs that the smallest microdroplets can travel beyond the two-metre limit.

“Where there’s some challenges is how much of it is due to the small aerosols that are transmitted when I’m close to you, or the larger droplets that tend to followed more readily and how much of it do I breathe deep into my lungs and how much of it is deposited in the upper airways,” Henry said.

The debate over droplets has been playing out since the pandemic began. Toronto infectious disease expert Dr. Isaac Bogoch told CTV News Channel on Monday that “there’s a spectrum between droplet and airborne” viruses.

“It’s a bit of a false dichotomy to say something is one or the other, but [this] infection really falls closer towards the droplet end of the spectrum, and when we use personal protective equipment to protect us against droplets and contact, we’re safe,” Bogoch said.

Bogoch said the open letter regarding airborne transmission of COVID-19 does not provide any new information about the virus.

“We’re just rehashing the same arguments that we’ve heard throughout February, March, April, up until now. I’m not quite sure what the fuss is all about,” he said.

The WHO reinforced that regardless of how the virus is transmitted, physical distancing measures and the use of face coverings have shown to help slow the spread.

DOCTORS SAY CURRENT PRECAUTIONS ARE WORKING

Henry wasn’t the only public health official to downplay the risk of airborne transmission of the virus, even as evidence mounts that it is possible.

In one study cited as an example in the letter, droplets were found to be the most likely source of transmission among three dining parties at a restaurant in China, in a case where surveillance video footage showed neither direct nor indirect contact between the groups.

Quebec’s chief public health officer Dr. Horacio Arruda acknowledged Monday that there is some evidence the coronavirus may be airborne, but insisted that is not the principal transmission vector.

“Most of the transmission — if not more than 95 per cent — is going to be done by droplets because that’s what the epidemiology told us. It doesn’t mean that in certain situations there is no aerosols… So I would say that there is a debate on this,” Arruda said during a news conference. “[But] I think that the issue is around droplets, not aerosols.”

While there remain various unknowns about COVID-19, Ontario Minister of Health Christine Elliott said she is “satisfied” with current evidence that the virus is not spread when physical distancing is maintained.

“In terms of people respecting social distancing, being out on patios right now, the public health is satisfied that that’s not going to transmit COVID. But we have to be concerned about indoor establishments,” Elliott said on Monday.

Elliot said Ontario is focused on contract tracing as it continues to reopen its economy and said the province’s declining case numbers show that current public health measures are working.

However, she said the province will evaluate its protections as more medical information regarding COVID-19 is confirmed, adding that airborne transmission of the virus “definitely will be borne in mind.”

Henry said B.C.’s approach to COVID-19 involves several different measures of protection that prevent transmission of both small and large droplets. She said that this includes various types of personal protective equipment for health-care workers, physical distancing and non-medical face mask for the public.

“In a number of the food production places where we had outbreaks early on, once we put in place measures like plexi-glass barriers, like wearing medical masks or non-medical masks, even ensuring we have safe distances between people, we stopped the transmission of this virus,” Henry said.

However, Henry said the province will continue looking at its transmission data and may enforce additional measures if cases begin to spike.

“The best way to protect people is making sure that sick people stay away from others, making sure that we are keeping our safe physical distancing [and] putting in place the administrative things to reduce the number of people in that environment,” Henry said.

In Bogoch’s view, Canada has proven that the current precautions and restrictions have slowed the spread of the virus.

“We’re using personal protective equipment to protect us from droplets and contact transmission of this virus… and when we use droplet precautions — the right mask, the right gloves, right down the right eye protection — we were using it properly and we’re not getting this infection,” Bogoch explained.

While some provinces may take further safety precautions, Bogoch said there is currently no risk that the virus will be contracted through airborne transmission.

“If someone had COVID-19, they were in a room, then they left the room and if someone just went into that room an hour later and they just stood there, they’re not going to get COVID-19,” Bogoch said.

With files from CTVNews.ca’s Ryan Flanagan

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Quebec's test positivity rate highest since May as COVID-19 infections climb – CBC.ca

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While the number of new COVID-19 cases in Quebec remains low when compared to the peak of the third wave, the test positivity rate hit 1.4 per cent on Sunday.

That’s the highest it’s been since late May, and new public health data shows infections are on the rise.

Quebec has reported an average of 139 new cases a day over the past seven days, up from an average of 57 a week prior.

Quebec Public Health reported 154 new cases of COVID-19 on Monday and 347 new infections were identified on Friday and Saturday.

There have been no new deaths attributed to the disease since Thursday but there are 61 COVID-19 patients in hospital — of those, 17 are in intensive care.

Dr. Donald Vinh, an infectious diseases specialist at the McGill University Health Centre, told The Canadian Press that the current trends are concerning as they show “there is still ongoing community transmission.”

The increased rate is based on fewer tests, he said.

On May 31, Quebec recorded a test-positivity rate of 1.5 per cent based on 15,783 tests. While on Sunday, Quebec analyzed only 11,202 tests.

With that data in mind, Vinh said the concern lies in the future, as schools and university classes resume in late August  and September.

“If it’s already increased when we are in the ‘safe’ outdoors,” he said, “what’s going to happen when we’re in the indoors?”

Quebec’s public health institute reported that 84.6 per cent of residents 12 and up have received at least one dose of vaccine while 68 per cent are adequately vaccinated.

Delta variant stirs worldwide worry

Meanwhile, health officials in the United States are sounding the alarm over the rapid spread of the delta variant which is described as extremely contagious, even among vaccinated people. It may also cause more serious disease than earlier coronavirus strains.

“High viral loads suggest an increased risk of transmission and raised concern that, unlike with other variants, vaccinated people infected with delta can transmit the virus,” said Rochelle Walensky, head of the U.S. Centers for Disease Control (CDC) in a statement last week.

On Friday, the CDC released data from a study of an outbreak in Massachusetts in which it said three-quarters of those infected had been fully vaccinated. 

Quebec has reported an average of 139 new cases a day over the past seven days, up from an average of 57 a week prior. (Jean-Claude Taliana/Radio-Canada)

The CDC recommends that Americans wear masks in areas with substantial transmission “regardless of vaccination status.”

The highly contagious variant, which was first discovered in India in late 2020, has spread around the world and now accounts for the majority of cases in Canada and various other countries. 

As of late July, the delta variant accounted for about five per cent of new cases in Quebec, compared to nearly 90 per cent of new cases in Ontario. 

For now, Quebec is continuing to scale back restrictions. For example, bars and restaurants are now officially allowed to serve alcohol until 1 a.m.— one hour longer than what was previously allowed. 

Stadiums, venues and festivals can welcome 15,000 spectators outdoors, up from 5,000.

The details on all changes can be found here.

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U.S. vaccination rate hits the highest pace in weeks – CTV News

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The rate of COVID-19 vaccinations in the United States continues to rise, a positive sign amid skyrocketing cases and hospitalizations after weeks of lagging inoculations.

The U.S. Centers for Disease Control and Prevention reported Sunday that 816,203 additional doses were administered, the fifth straight day the agency recorded more than 700,000 shots in arms. That brings the total number of doses administered to 346,456,669, according to the CDC numbers released Sunday.

The seven-day average of administered doses is now 662,529 per day, the highest average since July 7.

Additionally, Sunday was the third day in a row that the seven-day average of people getting their first shots topped 400,000. The last time that metric was over 400,000 was the July Fourth weekend.

That’s still less than a quarter of the peak in mid-April, when nearly 2 million people were getting their first shot each day.

If the U.S. picked up vaccinations to the April pace, it would take only a month and a half to reach all eligible people.

Per CDC data released Sunday, 168.4 million people are fully vaccinated, or 49.6% of the U.S. population. Among vaccine-eligible Americans — meaning those who are 12 and older — 58.1% are fully vaccinated.

Dr. Francis Collins, director of the National Institutes of Health, hopes the recent surge in cases driven by the Delta variant is changing the minds of the vaccine hesitant, he told CNN’s Jake Tapper Sunday. Collins noted that in the last two weeks, vaccination rates have increased 56% nationally.

“This may be a tipping point for those who have been hesitant to say, ‘OK, it’s time,'” Collins said. “I hope that’s what’s happening. That’s what desperately needs to happen if we’re going to get this Delta variant put back in its place.”

Overall, the seven-day average of people becoming fully vaccinated each day is at 247,385 people per day.

Twenty states have now fully vaccinated more than half of their residents, including Colorado, Connecticut, Hawaii, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia and Washington state, as well as Washington, DC.

On the other hand, the states with the lowest percentage of their population vaccinated are Alabama and Mississippi, which have 34% and 35% of their residents vaccinated, respectively.

Correction: An earlier version of this story and headline gave the wrong timing for when the doses were administered. The Centers for Disease Control and Prevention reported the additional doses Sunday, but it’s not clear when they were all administered.

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Delta spreads 'like wildfire' as doctors study whether it makes patients sicker – CTV News

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LOS ANGELES —
With a new wave of COVID-19 infections fuelled by the Delta variant striking countries worldwide, disease experts are scrambling to learn whether the latest version of coronavirus is making people – mainly the unvaccinated – sicker than before.

The U.S. Centers for Disease Control and Prevention warned that Delta, first identified in India and now dominant worldwide, is “likely more severe” than earlier versions of the virus, according to an internal report made public on Friday.

The agency cited research in Canada, Singapore and Scotland showing that people infected with the Delta variant were more likely to be hospitalized than patients earlier in the pandemic.

In interviews with Reuters, disease experts said the three papers suggest a greater risk from the variant, but the study populations are limited and the findings have not yet been reviewed by outside experts. Doctors treating patients infected with Delta described a more rapid onset of COVID-19 symptoms, and in many regions an overall increase serious cases.

But the experts said more work is needed to compare outcomes among larger numbers of individuals in epidemiologic studies to sort out whether one variant causes more severe disease than another.

“It’s difficult to pin down increase in severity and population bias,” said Lawrence Young, a virologist at the UK’s Warwick Medical School.

In addition, it is likely that the extraordinary rate of Delta transmission is also contributing to a greater number of severe cases arriving at hospitals, the experts said.

Delta is as contagious as chickenpox and far more contagious than the common cold or flu, according to the CDC report.

Shane Crotty, a virologist at the La Jolla Institute for Immunology in San Diego, said the clearest indication that the variant may cause more severe disease comes from the Scotland study, which found that Delta roughly doubled the risk of hospitalization compared to an earlier version.

The majority of hospitalizations and deaths from coronavirus in the United States are occurring in people who have not been vaccinated. But there is evidence that the shots are less effective in people with compromised immune systems, including the elderly.

For vaccinated, otherwise healthy individuals, the odds are that if they contract COVID-19 they will only experience asymptomatic or mild disease, said Dr. Gregory Poland, infectious disease expert at the Mayo Clinic.

“But they can pass it on to family members and others who may not be so lucky,” Poland said. “We have to be vaccinated and masked or we will, for the fourth time now, endure another surge and out of that will come worse variants.”

‘FULL-ON FLAMES’

The rate of severe illness, especially in regions where vaccination rates are low, is again straining healthcare workers on the front lines of the pandemic.

“This is like a wildfire, this is not a smouldering campfire. It is full-on flames right now,” said Dr. Michelle Barron, senior medical director of infection prevention and control at Colorado’s UCHealth.

Research from China suggesting that the Delta variant replicates much faster and generates 1,000 times more virus in the body compared to the original strain highlights the biggest danger of this new wave, Barron said.

“It is hard to tell if they are more sick because of the Delta variant or if they would have been more sick anyway,” she said.

Other doctors said patients infected with Delta appear to become ill more quickly, and in some cases with more severe symptoms, than those they treated earlier in the pandemic.

“We are seeing more patients requiring oxygen sooner,” said Dr. Benjamin Barlow, chief medical officer at American Family Care, a 28-state chain of urgent care clinics.

At his clinic in Birmingham, Alabama, Barlow said that around 20 per cent of patients are testing positive for COVID-19, compared with two to three per cent a few weeks ago. Patients are assessed at that time for potential hospital admission and oxygen support.

David Montefiori, director of the Laboratory for AIDS Vaccine Research and Development at Duke University Medical Center, said the Delta variant is more infectious and leads to faster onset of illness – particularly for the unvaccinated.

“Frankly there’s a severity that comes from this variant that is a little more severe,” Montefiori said on a webcast last week. “It’s not just easier to transmit, it makes you sicker.”

(Reporting by Deena Beasley in Los Angeles, Josephine Mason in London and Julie Steenhuysen in Chicago; Editing by Michele Gershberg and Daniel Wallis)

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