“Strong evidence” COVID-19 spreads primarily in the air, Lancet’s study states

According to a new assessment published Friday in The Lancet Journal, there is consistent and strong evidence that the SARS-CoV-2 virus behind the COVID-19 pandemic is predominantly transmitted in the air.

According to an analysis by six experts from the United Kingdom, the United States and Canada, public health measures that do not allow the virus to be treated primarily as airborne substances do not protect people and allow the virus to spread.

Several studies in the past have suggested that COVID-19 may spread in the air, but the overall scientific literature on this subject was not conclusive.

Last July, more than 200 scientists from 32 countries wrote to WHO, stating that there was evidence that the coronavirus could levitate and infect people with smaller particles.

“The evidence for airborne propagation is overwhelming, and there is little evidence for large droplet propagation,” said Jose-Luis Jimenez of the University of Colorado at Boulder.

“There is an urgent need for the World Health Organization and other public health organizations to adapt the infection description to scientific evidence so that the focus of mitigation is on reducing aerial infections,” Jimenez said.

A team led by researchers at the University of Oxford in the United Kingdom reviewed published studies and identified 10 lines of evidence to support the superiority of aerial routes.

Researchers highlighted a superspreading event in which 53 people were infected from a single case, including the outbreak of the Skagit Choir in the United States last year.

Studies have confirmed that these events cannot be fully explained by close contact with or touching shared surfaces or objects.

They pointed out that SARS-CoV-2 infection rates are much higher indoors than outdoors, and indoor ventilation significantly reduces infection.

The team cited a previous study that estimated that asymptomatic or presymptomatic asymptomatic infections of SARS-CoV-2 from people who did not cough or sneeze accounted for at least 40% of all infections. ..

This silent transmission is an important way that COVID-19 has spread all over the world, and according to the evaluation, it “mainly supports the transmission mode in the air”.

Researchers also emphasized studies demonstrating long-distance transmission of the virus among people in adjacent rooms of the hotel.

On the contrary, the team found little or no evidence that the virus spread easily through large droplets, which rapidly fall into the air and contaminate the surface.

“We were able to identify and interpret a very complex and specialized treatise on fluid flow dynamics and isolation of live viruses,” said Trish Greenhalgh, lead author of the study.

“Several individual treatises were rated weak, but overall, the evidence base for aerial propagation is broad and robust,” Greenhalgh added.

He said there should be no further delay in implementing measures to protect against such infections around the world.

The assessment has serious implications for public health measures designed to mitigate the pandemic, the researchers said.

They said that “droplet measures” such as hand washing and surface washing are important, but should not be emphasized more than aerial measures dealing with inhalation of infectious particles floating in the air.

According to researchers, when the infectious virus is primarily suspended in the air, inhaling the aerosol produced when the infected person exhales, speaks, screams, sings, or sneezes, Someone can get infected.

They said that some aerial control measures include ventilation, air filtration, congestion reduction, and the length of time people spend indoors.

According to researchers, always wear a mask indoors, pay attention to the quality and fit of the mask, and use high quality PPE for healthcare and other staff when contacting potentially infected people. Wearing is part of other control measures.

Co-author of the study, Professor Kimberly Placer of the University of California, San Diego, said:

“Only by including inhalation of aerosols at both short and long distances can we explain the many indoor outbreaks that have occurred around the world. If we admit that the virus is levitating, we can explain it. I know how to fix it, “Prather said.

Researchers added that there are many examples of places where the virus worked much better by admitting that it was levitating from the beginning, and that the world needs to follow their leadership as soon as possible.