Transmission of Covid-19: In what ways are we at risk of catching the coronavirus?

Faced with the gradual resumption of the Covid-19 epidemic, vigilance is more essential than ever. Wearing a mask, washing hands, physical distancing… These are all essential barrier gestures to limit the spread of the coronavirus, which is transmitted mainly through droplets of saliva. But the more the epidemic progresses, the more we learn about the different modes of transmission. In what ways are we at risk of catching the coronavirus?

Covid-19: saliva droplets, the main vector of contamination

Covid-19 is transmitted mainly through droplets of saliva emitted by an infected person when they cough or sneeze. This is also the reason why a gap of one meter between individuals has been recommended since the start of the epidemic. This distance makes it possible to avoid large particles, which are particularly contaminating, which, due to their weight, quickly fall to the ground.

Covid-19 is transmitted via surfaces and contacts

The disease caused by the Sars-CoV-2 coronavirus can also be transmitted during direct contact with an infected person, namely a handshake, a kiss or a hug. It is also possible to be contaminated via surfaces on which contaminating droplets are deposited. In these two cases, “the virus is then transmitted to a healthy person who handles these objects, when she puts her hands to her mouth”, can we read on the government website.

If contamination is possible via objects, it is because the coronavirus could survive for several hours, or even several days on certain surfaces. Its lifespan is thus estimated at 4 hours on copper, up to 24 hours on cardboard and up to 3 days on plastic and steel, according to a study conducted by American researchers from the National Institutes of Health and published on the scientific prepublication site MedRxiv last March.

On tissue, the coronavirus could survive for up to two days, according to a study published in May 2020 in the journal The Lancet. “However, just because a little virus survives does not mean that it is enough to infect a person who touches that surface. Indeed, after a few hours, the vast majority of the virus dies and is probably no longer. contagious”, can we nevertheless read on the website of the Ministry of Health.

Covid-19: possible contamination by the air?

Many researchers are wondering about a potential contamination by air. If this mode of transmission is not yet proven, a new study published on the scientific prepublication site MedRixv suggests that the microdroplets emitted when we speak or even when we breathe remain suspended in the air and can transmit the coronavirus.

Researchers at the University of Nebraska (USA) conducted an experiment with patients who were bedridden in rooms. Speaking, these produced microdroplets which remained suspended in the air for several hours. Scientists took these microdroplets present in the air, before placing them in culture. The virus “replicates in cell culture and is therefore infectious”, found Joshua Santarpia, co-author of the study. However, the authors stress that further research is needed to confirm these results.

Covid-19: apply barrier gestures to limit the risk of transmission

These different modes of transmission underline the importance of barrier gestures. It is therefore advisable to:

• wear a protective mask;
• wash your hands regularly with soap and water, or with hyroalcoholic gel in the absence of a water point;
• cough or sneeze into the crease of his elbow;
• use disposable tissues and throw them away immediately afterwards;
• maintain a physical distance of at least one meter, and therefore stop hugs, hugs and handshakes.

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