This photo taken on July 5, 2020 shows a staff member wearing protective clothing spraying disinfectant at an examinaton room ahead of the National College Entrance Examination (NCEE), known as Gaokao, in Wuhan in China's central Hubei province. China's annual nationwide college entrance examination will start on July 7, 2020.
AFP/STR
Global experts warn of COVID-19 airborne threat
Issam Ahmed (Agence France-Presse) - July 7, 2020 - 7:23am

WASHINGTON, United States — As countries ease their lockdowns, authorities need to recognize the coronavirus can spread through the air far beyond the two meters (six feet) urged in social distancing guidelines, an international group of 239 scientists said Monday.

In a comment piece that takes direct aim at the World Health Organization for its reluctance to update its advice, researchers recommended new measures including increasing indoor ventilation, installing high-grade air filters and UV lamps, and preventing overcrowding in buildings and transport. 

"There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale)," wrote the authors, led by Lidia Morawska of the Queensland University of Technology.

"Hand washing and social distancing are appropriate, but in our view, insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people."

The new paper appears in the Oxford Academic journal Clinical Infectious Diseases.

When an infected person breathes, speaks, coughs or sneezes, they expel droplets of various sizes. 

Those above five to ten micrometers — which is less than the width of a typical human head hair — fall to the ground in seconds and within a meter or two.

Droplets under this size can become suspended in the air in what is called an "aerosol," remaining aloft for several hours and traveling up to tens of meters.

There has been a debate in the scientific community about how infectious microdroplets are in the context of COVID-19.

For the time being the WHO advises that the potential for infection from an aerosol occurs "in specific circumstances"  mainly in hospitals, for example when a tube is placed down a patient's airway.

On the other hand, some studies of particular spreading events suggest that aerosolization and microdroplet transmission can happen in a variety of settings.

The air flow from an air conditioning unit appeared to waft the coronavirus to several tables in a Chinese restaurant in January where patrons became infected, according to a study that appeared in Emerging Infectious Diseases.

Another study that appeared in a report by the Centers for Disease Control and Prevention indicated that the virus was spread by microdroplets from people singing during a choir practice in Washington state in March.

Fifty-three people fell ill at that event and two died.

That is in addition to the fact that bars jam-packed with people have also emerged as hotspots of contagion, with droplets of all sizes believed to contribute to the spread.

Cath Noakes, a professor of environmental engineering for buildings at the University of Leeds, who contributed to the paper, said COVID-19 doesn't spread in the air as easily as measles or tuberculosis, but is a threat nonetheless.

"COVID-19 is more likely to be 'opportunistically' airborne and therefore poses a risk to people who are in the same room for long periods of time," she added.

The WHO advice is out of step with both the US CDC and its European counterpart.

"We are aware of the article and are reviewing its contents with our technical experts," the WHO said in response to the new commentary.

'Precautionary principle'

The authors recognized that the evidence for microdroplet transmission was "admittedly incomplete," but argued that the evidence for large droplets and surface transmission was also incomplete yet still formed the basis for health guidelines.

"Following the precautionary principle, we must address every potentially important pathway to slow the spread of COVID-19," they wrote.

Put another way, "absence of evidence is not evidence of absence," said Julian Tang, an associate professor of respiratory sciences at the University of Leicester who contributed to the commentary.

"The WHO say that there is insufficient evidence to prove aerosol/airborne transmission of SARS-CoV-2 is happening. We are arguing that there is insufficient proof that aerosol/airborne transmission does not occur," he said.

AIRBORNE NOVEL CORONAVIRUS
As It Happens
LATEST UPDATE: August 9, 2020 - 12:33pm

Follow this page for updates on a mysterious pneumonia outbreak that has struck dozens of people in China.

August 9, 2020 - 12:33pm

Brazil on Saturday surpassed 100,000 coronavirus deaths and three million cases of infection, crossing the grim milestone after President Jair Bolsonaro said he had a "clear conscience" on his response to the outbreak.

With 100,477 fatalities and 3,012,412 confirmed cases, the South American nation of 212 million people is the second hardest-hit country in the global pandemic, after the United States.

The health ministry reported 905 new deaths in the past 24 hours, as well as 49,970 fresh cases. 

But the official figures are most likely an undercount, with experts estimating that the total number of infections could be up to six times higher due to insufficient testing. — AFP

August 9, 2020 - 9:33am

Two new confirmed imported cases of COVID-19 in Taiwan had recently come from the Philippines, Taiwan's Centers for Disease Control says in an August 8 announcement.

The two, identified as Cases 478 and 479, are a couple and are both 60 years old. They had been in the Philippines since earlier this year.

"The male case developed a fever, a runny nose, and fatigue on July 23. The female case experienced an itchy throat and cough on August 3. Their symptoms were relieved after taking medications, but they didn't seek medical attention in the Philippines," Taiwan CDC says.

They returned to Taiwan on August 6 and reported their symptoms to quarantine oficers when they arrived at the airport. They were brought to a quarantine facility and lab tests confirmed on August 8 that they had COVID-19.

August 8, 2020 - 4:47pm

The Department of Health reports 4,226 new cases of coronavirus disease 2019, bringing the national tally to 126,885.

There are 287 additional survivors and 41 new deaths.

August 7, 2020 - 5:08pm

Reports say that former Manila mayor Alfredo Lim has been confined at an undisclosed hospital reportedly due to the coronavirus disease.

Lim’s grandson, Manila 1st District Councilor Niño Dela Cruz, earlier requested for prayers for the healing of the former mayor. The post has been deleted. — The STAR/Rey Galupo

August 7, 2020 - 4:07pm

The Department of Health announces 3,379 new cases of the coronavirus disease, bringing the national caseload to 122,754 in the Philippines.

There are 96 new recoveries and 24 new deaths.

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