[D66] Verspreiding coronavirus via ademhaling (Wuhan Coronavirus 2019-nCoV #108)

[Dr. Marc-Alexander Fluks]

Afgelopen donderdag mailde ik,
> U.S. National Academy of Sciences, Engineering, and Medicine:
> Ademhalen en praten, niet alleen hoesten, brengt coronavirus over,
> https://nam.edu/coronavirus-resources/

Bron:   AFP
Datum:  3 april 2020
Auteur: Issam Ahmed
URL:    
https://www.afp.com/en/news/15/coronavirus-may-spread-through-normal-breathing-us-scientists-doc-1qd5xo1


Coronavirus may spread through normal breathing: US scientists
--------------------------------------------------------------

Washington (AFP) - The new coronavirus might spread through the air via 
normal breathing and speaking, a top US scientist said Friday as the 
government was poised to recommend the use of face masks for everyone.

Anthony Fauci, head of infectious diseases at the National Institutes of 
Health, told Fox News the guidance on masks would be changed 'because of 
some recent information that the virus can actually be spread even when 
people just speak, as opposed to coughing and sneezing.'

As it stands, the official advice is that only sick people need to cover 
their faces, as well as those caring for them at home.

Fauci's comments come after the National Academy of Sciences (NAS) sent 
a letter to the White House on April 1 that summarized recent research 
on the subject.

It said that though the research isn't yet conclusive, 'the results of 
available studies are consistent with aerosolization of virus from 
normal breathing.'

Until now, US health agencies have said that the primary pathway of 
transmission is respiratory droplets, about one millimeter in diameter, 
expelled by sick people when they sneeze or cough.

These quickly fall to the ground around a meter away.

But if the virus can be suspended in the ultrafine mist we expel when we 
exhale, in other words an aerosol, it becomes much harder to prevent its 
spread, which in turn is an argument in favor of everyone covering their 
faces.


The aerosol debate

A recent NIH funded study published in the New England Journal of 
Medicine found that the SARS-CoV-2 virus could become an aerosol and 
remain airborne for up to three hours.

This triggered a debate even as critics said the findings were overblown 
because the team behind the study used a medical device called a 
nebulizer to deliberately create a viral mist and argued this would not 
occur naturally.

The NAS letter pointed to preliminary research by the University of 
Nebraska Medical Center that found the genetic code of the SARS-CoV-2 
virus, its RNA, were found in hard to reach areas of patients' isolation 
rooms.

The NAS scientists also pointed to two other studies - both not yet peer 
reviewed - from Hong Kong and from mainland China.

The Hong Kong researchers collected viral samples from patients with the 
coronavirus and other viral respiratory illnesses, and gave some of the 
patients face masks.

The masks reduced the detection of both droplets and aerosols for 
coronavirus patients.

The Chinese paper on the other hand raised concerns that personal 
protective gear used by health care workers could itself be a source of 
airborne virus.

The team studied hospitals in Wuhan and found that there were two major 
areas where the virus was aerosolized: the bathrooms of patients, and 
rooms where medical staff removed their protective gear.

This may be because doffing protective gear causes the particles to get 
re-suspended in the air. Even if these particles are not of breathable 
size, they could settle on people's hands and bodies, the NAS panel 
said.

So far, the World Health Organization (WHO) has been more cautious on 
the airborne threat.

In an analysis published on March 29, it wrote that aerosol transmission 
was only known to occur during particular medical treatments that 
required assisted breathing.

On the recent preliminary research, such as the University of Nebraska's 
paper, the WHO cautioned that the detection of the virus' genetic code 
in patient's rooms did not necessarily amount to viable amounts of the 
pathogen that could be transmitted onward.

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(c) 2020 AFP