The main reasons why the new SARS-CoV-2 or COVID-19 infection occurs is because the recommendations for containment are not put into practice and people not complying with hygiene and disinfection regulations.
A person can start spreading it to others before symptoms appear, perhaps a day earlier, and then continues to spread the virus for at least seven more days.
All viruses are different and this new one seems to be very adapted to be easily transmitted in humans. This is where the real danger of SARS-CoV-2 is and why the health authorities are putting so much emphasis on social distancing.
The Virus can only survive if it finds a new host to infect. When an infected person stays at home for 14 days, it eliminates the possibility of spreading the Virus to someone else.
Why the COVID-19 is spread so efficiently
Several studies are investigating what are the biological mechanisms that the Virus uses to infect human cells so easily. Some scientists are focusing on so-called spikes, the spike-shaped proteins that protrude from its surface to form a corona. Other studies are studying “the gateway” that the virus uses to enter cells.
“Coronaviruses have that name because of the spike proteins that protrude from their surface, and these spikes are the ones that attach to the cell to enter it, the main mission of the Virus once it enters the body is to create copies of itself, and to do so it needs to find a way to enter the cells”, says Panagis Galiatsatos, professor of pulmonary medicine and intensive care at the Johns Hopkins University School of Medicine.
Some studies have shown COVID-19 “slips away” from a receptor or protein called ACE2
This protein is found in many parts of the human body: in the lungs, heart, kidneys and intestines, and its main function is to reduce blood pressure.
“ACE2 is on the surface of the cell and when the Virus recognizes, it binds and thus enters the cell, once inside, it uses the machinery of the cell as a factory to make copies of itself and its genetic material. After it escapes from the cell, of which only one shell remains, they are ready to start infecting other cells,” explains Sarah Gilbert, professor of Vaccinology at the University of Oxford, in the UK.
Respiratory viruses, like the common cold, tend to reproduce in the nose and throat, where they can easily be spread by coughing or sneezing. But there are other Viruses that only reproduce in the lower respiratory tract, in the lungs, where they spread less easily but are much more dangerous.
SARS-CoV-2, differences from other coronaviruses
One of the main differences between SARS-CoV-2 or COVID-19 and other Coronaviruses is that the other viruses adhere to more cellular receptors and therefore reproduce faster.
This caused the symptoms of the disease to appear much faster and the patients could isolate themselves without causing so many infections. With the new coronavirus, symptoms don’t appear right away, and people can get the Virus and spread it without showing signs of the disease.
“SARS was a virus that was produced in the lungs and was not transmitted so easily because the symptoms appeared quickly and the patient could be isolated. COVID-19 is contagious within the mucous areas, by contact, that is, being a heavy virus, it falls on the surface, if we have gloves and a mask, it would not do any good, since if we put our gloved hand and bring them to our faces, we would be infected”, Professor David Hymann, an expert in infectious diseases declares.
Undoubtedly, the most effective way to avoid the spread of COVID-19 is by complying with the protocols established by the health authorities. It is a matter of conscience, care and respect for our life and that of others.