Predominant form of Covid-19
There is consistent, strong evidence to prove that the SARS-CoV-2 virus, behind the Predominant form of Covid-19 pandemic, transmitted through the air. According to a new assessment published on Friday in The Lancet journal.
The analysis by six experts from the UK, the US and Canada says public health measures fail to treat the virus as predominantly the airborne route leaves people unprotected and allows the virus to spread.
Although some studies in the past have suggested that COVID-19 may spread through air. overall scientific literature on the subject has been inconclusive.
In July last year, over 200 scientists from 32 nations wrote to the WHO, saying there is evidence that the coronavirus is airborne, and even smaller particles can infect people.
“The evidence supporting airborne transmission is overwhelming. Evidence supporting large droplet transmission is almost non-existent,” said Jose-Luis Jimenez, from the University of Colorado Boulder in the US.
“It is urgent that the World Health Organization and other public health agencies adapt their description of transmission. To the scientific evidence so that the focus of mitigation is put on reducing airborne transmission. Jimenez said Studies have confirmed these events cannot be adequately explained by close contact or touching shared surfaces or objects, the researchers said in their assessment.
They noted that transmission rates of SARS-CoV-2 are much higher indoors than outdoors, and transmission is greatly reduced by indoor ventilation. The team cited previous studies estimating that silent – asymptomatic or presymptomatic – transmission of SARS-CoV-2 from people who are not coughing or sneezing accounts for at least 40 percent of all transmission.
This silent transmission is a key way COVID-19 has spread around the world, “supporting a predominantly airborne mode of transmission,” according to the assessment.
The researchers also highlighted work demonstrating long-range transmission of the virus between people. In adjacent rooms in hotels, who were never in each other’s presence. On the contrary, the team found little to no evidence that the virus spreads easily via large droplets. Which is fall quickly through the air and contaminate surfaces.
“We were able to identify and interpret highly complex and specialist papers on the dy fluid flows and the isolation of live virus,” said study lead author Trish Greenhalgh.
“While some individual papers were assessed as weak, overall the evidence base for air transmission is extensive and robust,” Greenhalgh added. He noted that there should be no further delay in implementing measures around the world to
protect against such transmission. The assessment has serious implications for public health measures designed to mitigate the pandemic, the researchers said.
They said “droplet measures” such as hand 2 of 4 surface cleaning, while important, should be given less emphasis than airborne. Measures which deal with inhalation of infectious particles suspended in the air.
“We were able to identify and interpret highly complex and specialist papers on the dynamics of fluid flows. The isolation of live virus,” said study lead author Trish Greenhalgh.
“While some individual papers were assessed as weak, overall the evidence base for airborne transmission is extensive and robust,” Greenhalgh added.
He noted that there should be no further delay in implementing measures around the world to protect against such transmission.
The assessment has serious implications for public health measures designed to mitigate the pandemic, the researchers said. They said “droplet measures” such as handwashing and surface cleaning, while important, should be given less emphasis than airborne measures, which deal with inhalation of infectious particles suspended in the air. According to the researchers, if an infectious virus is primarily airborne, someone can potential be infected when they inhale aerosols produced when an infected person exhales, speaks, shout sings, or sneezes.
They noted that some airborne control measures include ventilation, air filtration, reducing crowding and the amount of time people spend indoors.
Wearing masks whenever indoors, attention to mask quality and fit, and higher-grade PPE for healthcare and other staff when working in contact with potentially infectious people are some of the other control measures, according to the researchers.
The researchers added that there are many examples of places that have fared much better by acknowledging this virus is airborne from the start, adding the world needs to follow their lead as soon as possible.