MADRID, 17 Sep. (EUROPA PRESS) –
The results of a new study led by the School of Public Health at the University of Maryland, in the United States, show that people infected with the virus that causes COVID-19 breathe out infectious viruses on their breath, and that those infected with the Alpha variant (the dominant strain circulating at the time this study was conducted) put 43 to 100 times more virus into the air than people infected with the parent strains of the virus.
Researchers also found that loose-fitting fabrics and surgical masks reduced the amount of virus that entered the air around infected people by about half, as published in the journal Clinical Infectious Diseases.
“Our latest study provides further evidence of the importance of airborne transmission,” says Dr. Don Milton, professor of environmental health at the University of Maryland School of Public Health (UMD SPH). Delta variant circulating now is even more contagious than the Alpha variant. Our research indicates that the variants continue to improve as they travel through the air, so we need to provide better ventilation and wear tight-fitting masks, in addition to vaccination, to help stop the spread of the virus. “
The amount of virus in the air from Alpha variant infections was much more – 18 times more – than could be explained by the higher amounts of virus in nasal swabs and saliva.
One of the lead authors, PhD student Jianyu Lai, explains that “the virus in saliva and nasal swabs was already known to increase in Alpha variant infections. The virus from the nose and mouth could be transmitted through the spraying large droplets near an infected person. But our study shows that the virus in exhaled aerosols increases even more “, he highlights.
These significant increases in airborne virus from Alpha infections occurred before the arrival of the Delta variant and indicate that the virus is evolving to better travel through the air.
To see if the masks work to prevent the virus from being transmitted between people, this study measured the amount of SARS-CoV-2 breathed in the air and tested the amount of virus that people breathed out into the air sick with COVID-19 after wearing a cloth or surgical mask.
The face covers significantly reduced the virus-laden particles in the air around the person with COVID-19, reducing the amount by about 50%, but the loose cloth and surgical masks did not prevent the infectious virus from passing into the air.
Dr. Jennifer German, one of the co-authors, points out that “the messages that can be taken home from this work are that the coronavirus can be in your exhaled breath, it is improving to be in your exhaled breath, and the use of a mask it reduces the possibility that you breathe it in others. “
This means that a layered approach to control measures (including better ventilation, increased filtration, UV air sanitation, and tight-fitting masks, is essential to protect people working in front of the public and indoors). in addition to vaccination).
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