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COVID-19 can be spread by building ventilation, say Canadian researchers – Toronto Sun

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Tom Blackwell, Postmedia News

The outbreak of COVID-19 at a restaurant in the southern Chinese city of Guangzhou was a puzzle.

The suspected index patient was a visitor from the coronavirus’ epicentre in Wuhan. But the eight other customers who later tested positive were not sitting close enough for droplet transmission, and most of the patrons and staff avoided infection altogether.

A team of local scientists eventually came to an eye-opening conclusion about the episode: tiny particles of virus had hitched a ride on currents created by the eatery’s air-conditioning.

That runs counter to the prevailing view that the novel coronavirus is transmitted only by heavier “droplets.” But for a group of civil engineers at the University of Alberta, the finding was no surprise. In their world, they say, it’s well known that building ventilation systems are efficient disseminators of viruses and other pathogens, and they believe the COVID-19 bug is no exception.

Aided by a $440,000 federal-government grant, they’re now working on ways that buildings could change their HVAC set-ups to curb the risk of infection, what the researchers call a “non-pharmaceutical” intervention against the disease.

“We want to save lives, let’s cut right to the chase,” said Prof. Brian Fleck, part of the project. “There are so many, many, many buildings … This affects absolutely everybody. Billions of people. If we are able to cut down the transmission rate by a per cent, that’s a lot of people.”

The engineers’ belief in the importance of building ventilation as a transmitter of the COVID-19 virus is not universally held.

The World Health Organization and other public-health bodies, citing the science to date, say the pathogen is spread almost entirely by droplets, heavier particles emitted mostly when infected people cough or sneeze, and which fall down within a short distance. Hence the two-metre rule for social distancing, and the emphasis on washing hands after touching surfaces where virus may have alighted.

“The HVAC systems in most non-medical buildings play only a small role in infectious disease transmission, including COVID-19,” argued the American Society of Heating, Refrigerating, and Air-Conditioning Engineers last month.

It’s just smaller and lighter aerosol particles that can spread through a ventilation system and “the truth is that we still don’t really know if the (COVID-19) virus can be spread by aerosols,” said Matthew Miller, a virus expert at McMaster University in Hamilton.

But Chinese and Australian air-quality experts, citing in part the experience with SARS, another coronavirus, argued in a paper earlier this month that as droplets from an infected person start to evaporate, the resulting smaller particles can indeed become airborne.

They point to evidence that passengers confined to their cabins on cruise ships like the Diamond Princess may have been infected through the vessels’ air ducts.

“It is highly likely that the SARS-CoV-2 virus also spreads by air,” they conclude, urging “all possible” action in response, including modifications to ventilation systems. “We predict that … failure to immediately recognize and acknowledge the importance of airborne transmission and to take adequate actions against it will result in additional cases.”

Then there was the Guangzhou restaurant case, detailed in a U.S. Centers for Disease Control online journal recently. Researchers concluded flow from an air conditioner moved over three tables, carrying virus from the infected patron at the middle one to the far table, then back to the diners closest to the air conditioner.

Even if it turned out SARS-CoV-2 does not spread that way, influenza viruses can, and the University of Alberta research would be valuable for that reason alone, said Miller.

Heating, ventilation and air conditioning (HVAC) engineers have long known that tiny particles of pathogen travel in the air that is circulated, heated and cooled in modern buildings, said Fleck. He pointed to Legionnaires disease, a bacterial pneumonia first traced to a hotel’s air-conditioning system.

“This has been on people’s radar for quite a while,” he said. “Somebody on a different floor sneezes …The particle can stay airborne long enough to go all the way through the system and then pop out in somebody else’s office.”

There are various ways that the risk can be lessened, including use of filters that catch a greater number of those particles, and drawing more fresh air into a system. It also is likely that higher levels of humidity – a factor that only some Canadian buildings can adjust – will help kill off the virus, said Fleck.

But each of those changes carries a cost. Adding more fresh air can require additional heat or air conditioning. Heavier filters means more energy is needed to push the air through them. And more humidity can lead to mould, he noted.

“This will make for difficult decision making.”

Funded by the Canadian Institute for Health Research, the University of Alberta project is led by engineering professor Lexuan Zhong and also involves pediatrics professor Lisa Hartling. It consists of three phases: systematically reviewing literature on air circulation and viruses, determining what strategies would be effective and then carrying out a detailed audit of all the buildings on the Edmonton campus to create a real-world model of what should be done.

The team hopes to have solid results by the summer of 2021, said Fleck.

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Whooping cough is at a decade-high level in US

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MILWAUKEE (AP) — Whooping cough is at its highest level in a decade for this time of year, U.S. health officials reported Thursday.

There have been 18,506 cases of whooping cough reported so far, the Centers for Disease Control and Prevention said. That’s the most at this point in the year since 2014, when cases topped 21,800.

The increase is not unexpected — whooping cough peaks every three to five years, health experts said. And the numbers indicate a return to levels before the coronavirus pandemic, when whooping cough and other contagious illnesses plummeted.

Still, the tally has some state health officials concerned, including those in Wisconsin, where there have been about 1,000 cases so far this year, compared to a total of 51 last year.

Nationwide, CDC has reported that kindergarten vaccination rates dipped last year and vaccine exemptions are at an all-time high. Thursday, it released state figures, showing that about 86% of kindergartners in Wisconsin got the whooping cough vaccine, compared to more than 92% nationally.

Whooping cough, also called pertussis, usually starts out like a cold, with a runny nose and other common symptoms, before turning into a prolonged cough. It is treated with antibiotics. Whooping cough used to be very common until a vaccine was introduced in the 1950s, which is now part of routine childhood vaccinations. It is in a shot along with tetanus and diphtheria vaccines. The combo shot is recommended for adults every 10 years.

“They used to call it the 100-day cough because it literally lasts for 100 days,” said Joyce Knestrick, a family nurse practitioner in Wheeling, West Virginia.

Whooping cough is usually seen mostly in infants and young children, who can develop serious complications. That’s why the vaccine is recommended during pregnancy, to pass along protection to the newborn, and for those who spend a lot of time with infants.

But public health workers say outbreaks this year are hitting older kids and teens. In Pennsylvania, most outbreaks have been in middle school, high school and college settings, an official said. Nearly all the cases in Douglas County, Nebraska, are schoolkids and teens, said Justin Frederick, deputy director of the health department.

That includes his own teenage daughter.

“It’s a horrible disease. She still wakes up — after being treated with her antibiotics — in a panic because she’s coughing so much she can’t breathe,” he said.

It’s important to get tested and treated with antibiotics early, said Dr. Kris Bryant, who specializes in pediatric infectious diseases at Norton Children’s in Louisville, Kentucky. People exposed to the bacteria can also take antibiotics to stop the spread.

“Pertussis is worth preventing,” Bryant said. “The good news is that we have safe and effective vaccines.”

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AP data journalist Kasturi Pananjady contributed to this report.

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The Associated Press Health and Science Department receives support from the Robert Wood Johnson Foundation. The AP is solely responsible for all content.

The Canadian Press. All rights reserved.

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Scientists show how sperm and egg come together like a key in a lock

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How a sperm and egg fuse together has long been a mystery.

New research by scientists in Austria provides tantalizing clues, showing fertilization works like a lock and key across the animal kingdom, from fish to people.

“We discovered this mechanism that’s really fundamental across all vertebrates as far as we can tell,” said co-author Andrea Pauli at the Research Institute of Molecular Pathology in Vienna.

The team found that three proteins on the sperm join to form a sort of key that unlocks the egg, allowing the sperm to attach. Their findings, drawn from studies in zebrafish, mice, and human cells, show how this process has persisted over millions of years of evolution. Results were published Thursday in the journal Cell.

Scientists had previously known about two proteins, one on the surface of the sperm and another on the egg’s membrane. Working with international collaborators, Pauli’s lab used Google DeepMind’s artificial intelligence tool AlphaFold — whose developers were awarded a Nobel Prize earlier this month — to help them identify a new protein that allows the first molecular connection between sperm and egg. They also demonstrated how it functions in living things.

It wasn’t previously known how the proteins “worked together as a team in order to allow sperm and egg to recognize each other,” Pauli said.

Scientists still don’t know how the sperm actually gets inside the egg after it attaches and hope to delve into that next.

Eventually, Pauli said, such work could help other scientists understand infertility better or develop new birth control methods.

The work provides targets for the development of male contraceptives in particular, said David Greenstein, a genetics and cell biology expert at the University of Minnesota who was not involved in the study.

The latest study “also underscores the importance of this year’s Nobel Prize in chemistry,” he said in an email.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

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Older patients, non-English speakers more likely to be harmed in hospital: report

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Patients who are older, don’t speak English, and don’t have a high school education are more likely to experience harm during a hospital stay in Canada, according to new research.

The Canadian Institute for Health Information measured preventableharmful events from 2023 to 2024, such as bed sores and medication errors,experienced by patients who received acute care in hospital.

The research published Thursday shows patients who don’t speak English or French are 30 per cent more likely to experience harm. Patients without a high school education are 20 per cent more likely to endure harm compared to those with higher education levels.

The report also found that patients 85 and older are five times more likely to experience harm during a hospital stay compared to those under 20.

“The goal of this report is to get folks thinking about equity as being a key dimension of the patient safety effort within a hospital,” says Dana Riley, an author of the report and a program lead on CIHI’s population health team.

When a health-care provider and a patient don’t speak the same language, that can result in the administration of a wrong test or procedure, research shows. Similarly, Riley says a lower level of education is associated with a lower level of health literacy, which can result in increased vulnerability to communication errors.

“It’s fairly costly to the patient and it’s costly to the system,” says Riley, noting the average hospital stay for a patient who experiences harm is four times more expensive than the cost of a hospital stay without a harmful event – $42,558 compared to $9,072.

“I think there are a variety of different reasons why we might start to think about patient safety, think about equity, as key interconnected dimensions of health-care quality,” says Riley.

The analysis doesn’t include data on racialized patients because Riley says pan-Canadian data was not available for their research. Data from Quebec and some mental health patients was also excluded due to differences in data collection.

Efforts to reduce patient injuries at one Ontario hospital network appears to have resulted in less harm. Patient falls at Mackenzie Health causing injury are down 40 per cent, pressure injuries have decreased 51 per cent, and central line-associated bloodstream infections, such as IV therapy, have been reduced 34 per cent.

The hospital created a “zero harm” plan in 2019 to reduce errors after a hospital survey revealed low safety scores. They integrated principles used in aviation and nuclear industries, which prioritize safety in complex high-risk environments.

“The premise is first driven by a cultural shift where people feel comfortable actually calling out these events,” says Mackenzie Health President and Chief Executive Officer Altaf Stationwala.

They introduced harm reduction training and daily meetings to discuss risks in the hospital. Mackenzie partnered with virtual interpreters that speak 240 languages and understand medical jargon. Geriatric care nurses serve the nearly 70 per cent of patients over the age of 75, and staff are encouraged to communicate as frequently as possible, and in plain language, says Stationwala.

“What we do in health care is we take control away from patients and families, and what we know is we need to empower patients and families and that ultimately results in better health care.”

This report by The Canadian Press was first published Oct. 17, 2024.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.

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