It is known that the coronavirus responsible for the COVID-19 is transmitted following close contact with people infected by inhaling the droplets that they project into the air when they cough, talk, or by contact with contaminated surfaces. However, we still do not know if the aerosols emitted by an individual as a carrier of the virus also contribute to the spread of the disease.
In an article published in the journal Nature, a team of researchers from the University of Wuhan, China, claim to have detected the viral RNA in the air of two hospitals as well as in public places where there were crowds. However, they have not verified if these viruses are present in the form of aerosols were infectious.
Researchers from the National Institutes of Health have shown with the aid of a laser the trajectory that describe the droplets of fluid that are generated and propelled in the air when we speak. In an article published in The New England Journal of Medicine, it is apparent that these droplets, which are likely to bring the virus particles spread more or less far according to their size.
The large droplets fall quickly to the ground because of their weight. The smaller can dehydrate and remain in the air in aerosol form, which increases the expanse of space that can hold infectious particles that would have been issued when an infected person speaks, underline the authors of the study.
In an article that appeared Monday in the journal Nature, researchers from the Wuhan University claim to have measured concentrations greater or less RNA of SARS-CoV-2 in the air of two hospitals in Wuhan as well as in public places, in February and march last.
The researchers found that very low concentrations of viral RNA in the ventilated rooms and rooms where a patient was placed in isolation, and this, presumably due to the large air change that is made in these places, argue the researchers. However, the air of the toilet, which was not disaggregated, exhibited high concentrations of virus.
The researchers also noted that the viral RNA was particularly abundant in the air of the areas of the hospital where medical personnel removed his protective equipment, “which suggests that” the aerosol-loaded virus can be found again in suspension in the air ” when the caregivers délestent of their equipment.
However, after that it has increased the frequency and the quality of the disinfection of those areas which are particularly contaminated, the viral RNA became undetectable.
The concentrations of genetic material of the SARS-CoV-2 were generally low in public places, such as residential buildings and supermarkets. However, two sites where flow in large crowds, including a place situated near one of the two hospitals, showed high concentrations of viral RNA that the researchers attribute to infected individuals among the crowd.
This study confirms that the aerosols, or droplets of very small size, can carry viral RNA, and therefore, that the SARS-CoV-2 can potentially be transmitted through aerosols. The authors of the study, however, have not verified if these aerosols loaded in the viral RNA are likely to transmit the COVID-19, a crucial piece of information that need to be put in the light, argue the researchers who have revised the article.
One of them points out that” a recent study has shown experimentally that the SARS-CoV-2 could maintain its biological stability in aerosols and on surfaces for hours or even days “, which would imply that the viruses detected in the study of Nature could be infectious.
These results must however be considered with caution, warn-they are also, given the low number of samples collected, 40 samples collected in 31 different locations.
Nevertheless, the study highlights the importance of sterilizing the places likely to be contaminated by aerosols responsible for virus, well ventilated rooms of the patients, and to avoid the combinations to reduce the risk of infection.
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