Coronavirus, Covid-19, disease, infection. A glossary to understand the terms of the epidemic
Here is a small glossary with the most common but also most misunderstood terms in this second pandemic wave
(illustration: Getty Images) Illness or infection? Coronavirus or Covid-19? On social media, on TV and on the media in general, there still seems to be some confusion about words and their meaning. That's why we decided to create a small glossary with the most common but also the most misunderstood terms in this second pandemic wave.Infection
Infection is a term that indicates the process in which a microorganism , like the coronavirus, it invades a cell / tissue and multiplies. Not all infections, however, cause symptoms, giving rise to disease in the host organism.The pathogenic microorganism that continues to keep us in check is the Sars-Cov-2 coronavirus. It first emerged in China in late January and was called 2019-nCov at the beginning of the epidemic. Subsequently, the International Committee on Taxonomy of Viruses renamed it in the current Sars-Cov-2 to underline the relationship with the coronavirus responsible for Sars (Sars-Cov, with which it shares approximately 80% of the genome) and the affinity of the clinical manifestations of the two infections (Covid-19 and Sars, in fact).
Disease
Speaking of pathogenic microorganisms, the disease is nothing more than a symptomatic infection.The disease caused by the Sars-Cov-2 coronavirus infection is called Covid-19. The name was chosen by the World Health Organization (WHO): "Co" stands for corona, "vi" for virus and "d" for disease (ie disease in English), while "19" indicates the year in which has manifested itself.
Viral load
By viral load is meant the quantity of viral particles present in an infected person. This in the stages after contagion tends to increase because the pathogen, evading the host's immune defenses, is able to penetrate the cells and exploit them to replicate and then infect other cells. If the immune system is able to fight the infection, the viral load will drop over time until every viral particle is eliminated. Viral load does not always go hand in hand with the extent of the pathological manifestations, that is, people with a very high viral load are not necessarily sicker than others with a lower viral load. Furthermore, the viral load can remain elevated even after the disease has healed.Asymptomatic
When the infection does not give rise to symptoms, we are talking about asymptomatic individuals. Not being able to know that they have been infected (if not with an ad hoc test), they can contribute to further spread the pathogen. The lack of symptoms, in fact, is not a sign of low viral load.In the case of Sars-Cov-2 infection, as far as we know now, many asymptomatic patients have low viral load and transmit the infection with more difficulty; on the other hand, there are also the so-called super-diffusers, that is completely asymptomatic people in whom, however, the viral load is very high and they are able to unknowingly infect a higher than average number of people.
From some studies (including the one on passengers of the Diamond Princess cruise ship) it seems that a certain percentage of people tested positive for the coronavirus but asymptomatic we still had subclinical repercussions, in particular in their chest X-rays there would be opacities, a clue perhaps that the virus has still affected the functionality of the lungs . If these evidences were confirmed by wider investigations, it would not be possible to say without having made checks that an asymptomatic positive is not sick.
