October 21, 2020

The scientific explanation of the coronavirus: NOT the apocalypse


The fear of the unknown is natural. In fact, it is one of those qualities to which we owe our survival. The darkness, an unexpected sound, everything that we cannot predict as we would like is cause for concern and in our days there is a fear that surpasses others: the biological danger. We talk about viruses and bacteria invisible to the naked eye, but potentially capable of killing us in a few days.

However, that archaic alarm that once helped us survive is no longer as useful as before. That it is natural to fear epidemics does not mean that it is the most appropriate. Luckily, we live in a world where health systems take these threats very seriously and put all possible measures to control their damage. Wuhan’s coronavirus is sowing fear, but how dangerous is it really?

Coronavirus science

It all started when, on December 8, a patient from Wuhan (Hubei, China) was diagnosed with an atypical pneumonia of unknown cause. He showed fever, dry cough, shortness of breath and his radiography revealed an inflammatory process in the lungs. On December 31, China reported that there were new cases of this disease to the rest of the world, and at that time, health gears from dozens of countries were launched.

In just one week, on January 7, 2020, the agent causing the outbreak was identified. It was a strain of coronavirus never seen in humans that was called “new coronavirus”, or to be more precise “2019-nCoV”. Only two days later, the first person infected with the new coronavirus had died.

Luckily, on January 9 the scientists managed to sequence the coronavirus RNA, the molecule that in these microorganisms fulfills the functions of DNA. They had managed to reveal the order in which the nitrogenous bases that make up their RNA are found, the blocks that keep the information necessary to build and operate the virus, those four molecules we call by letters: A de Adenina, G de Guanina , C of Citosina and U of Uracilo. We had the enemy’s plans.

The negative part is that, as much as we know their plans, there is a long way to go to know how to take advantage of them, and by February 1 we are already around 10,000 affected. However, that we still don’t know how to neutralize the virus does not mean that we don’t know anything about it.

10,000 years ago they are among us

We have known the coronaviruses for a long time, in fact, they have been with us for more than 10,000 years and, after the rhinoviruses, they are primarily responsible for the common cold. Some strains of coronavirus have already seizures and others are still active. Classic examples are severe acute respiratory syndrome (SARS-CoV), which killed 349 people in 5970 cases. Or the Middle East respiratory syndrome (MERS-CoV) where deaths amounted to 912 of a total of 2494 infected.

And although it may not seem like it, this relationship is positive, because, as is the case with us, viruses tend to have more things in common with their closest relatives than with complete strangers. So, by simple comparison, we can deduce some things about how the new coronavirus behaves.

Image of the board developed by the Johns Hopkins CSSE that collects the cases of coronavirus in real time

ESRI
01/31/2020

Image of the board developed by the Johns Hopkins CSSE that collects the cases of coronavirus in real time

ESRI
01/31/2020 (/)

Precisely, this is the reason why it is suspected that the new coronavirus may be contagious even before the infected develop perceptible symptoms (and not because it has actually been shown), or that the incubation period is probably one week (from 2 to 12 days). These approaches help us know in which direction to investigate. For example, given that other coronaviruses are zoonotic (that jump from animals to humans), there may also be an animal after the outbreaks of coronaviruses, but which one? Normally, zoonoses are diseases that have been affecting the same species for a long time, but that, by random mutations, suddenly become capable of infecting humans.

Possibly come from bats

So, taking advantage of this information, other scientists have continued sequencing the RNA of the new coronavirus, and have found that it closely resembles that of a strain that primarily affects bats. We speak of a similarity of 98.99%, which points to them as a possible origin of zoonosis, specifically the family Rhinolophidae, commonly known as horseshoe bats.

Along the same lines, some scientists are trying to take advantage of the so-called “molecular clock” to know how long ago, the 2019-CoVn began to differentiate itself from their ancestors already present in bats. We could compare this molecular clock with a moisture stain produced by a leak: the drops fall more or less regularly, so the size of the moisture stain gives an idea about when the drip began. Similarly, mutations, small changes in the RNA of these coronaviruses, occur in a rhythm we know. Seeing how much the new coronavirus is different from the coronavirus of bats we can deduce how long ago it began to infect humans. [1]

However, this type of process requires an intermediate host, a third species that shelters the virus between the supposed bat and the human, an animal that, for now, has not been identified. When in doubt, controlling the consumption of animals and avoiding contact with them are measures of prevention of the first importance.

The broadcast

Many people, including some influencers In the healthcare world, they have sown confusion about how this new virus is spread. Everything indicates that it is very difficult to get infected being more than two meters from the infected person, since the virus does not travel through the air, but in body fluids, such as Flügge droplets, which is what is called the mucus and saliva that is It escapes us when we sneeze or cough. The masks are only necessary if we are going to be less than a meter from a possible affected. Therefore, it makes no sense to recommend its use to all patients and healthcare professionals of a hospital, much less if no cases have been detected in the area.

What we have to maintain are the basic hygiene measures: coughing in our forearms so as not to contaminate our hands and thus not contribute to the spread of the virus; wash your hands after coming into contact with people with symptoms; etc. In short, what we should always do, with or without a new coronavirus.

However, when talking about the speed at which the virus spreads, we usually talk about the basic reproductive rate, or R0, which is the number of people to whom, on average, an infected person can spread the pathogenic microorganism. If he R0 is greater than 1 means that the infection is spreading and in the case of the coronavirus it is estimated to be between 1.4 and 2.5. However, no matter how high it may seem, it is not so low, it is inferior to that of influenza or HIV and is far below that of other diseases such as measles, which can overcome R0 of 12. In fact, experts believe that the infectivity of the virus is relatively low among people, perhaps because it has still adapted little to our species since it abandoned its former host. Moreover, this value could be biased and be even lower than what we are perceiving, something that we will only know as the situation develops, since the reproductive rhythm changes over time.

External and internal structure of the 2019-nCoV which means (Glycoprotein Spicule, Protein M, Hemagglutinin Esterase, Envelope, NRA and N protein, Protein E)

External and internal structure of the 2019-nCoV which means (Glycoprotein Spicule, Protein M, Hemagglutinin Esterase, Envelope, NRA and N protein, Protein E)

But then why so much alarm?

It is common to confuse transmissibility (what we have just seen) with lethality. This second refers to how harmful a microbe can be. So far, there have been more than 200 deaths and a lethality of 2% is calculated, which has caused the media alarms to jump. However, and although it sounds counterintuitive, these figures, although sad, are not as serious as they seem.

2% is high, but there have been epidemics such as SARS in 2003 that reached a lethality of 15% in some areas, such as Singapore. And what is even more important: like transmissibility, lethality is a dynamic parameter and with the appropriate measures it can be reduced. The truth is that there is a key factor in this whole dance of numbers and that is that it is a new disease.

This means that only the most serious cases tend to be detected and confuse the milder ones with other classic diseases, so lethality is expected to decrease as diagnostic criteria improve. In the same way, the excessive increase in cases is due in part to this improvement in diagnosis, so, when more patients are detected, it contributes to appear that it is growing at a higher rate than it actually does.

Moreover, when diagnosing only complicated cases, the severity seems greater than it really is, but if we look, the people who have died corresponded to the so-called “risk groups.” Groups that, whether at an advanced age, being very young, having an ineffective immune system and a long list of vulnerabilities, are more likely to develop complications, increasing mortality from microorganisms to which we are most familiar, such as flu virus.

All this, although it may not seem like it, is mathematics. Models of how an infection behaves and have been widely studied to help predict and control situations like these. That is why we know that these outbreaks do not grow exponentially forever, but usually stabilize in a few weeks if appropriate measures are used. We just have to look back at what happened with the MERS-CoV or with the SARS-CoV. We are in better hands than we think and if everything is so “revolutionized” it is because the toilets are doing their job, following that maxim of “prevention is better than cure. We have to be alert, but with a head. Although if this gets complicated, can we cure?

The cure

Unfortunately we still don’t know a single drug that treats or prevents the spread of any coronavirus, however, scientists are trying to find it. There are some interesting clues, such as the envelope that covers the virus and gives it its name “coronavirus” for remembering the solar corona. The so-called “spicules” (peplomers in particular), key projections for the virus, extend from the surface of the microorganism, because they contain the proteins that will “open the doors” of our cells, to infiltrate them and infect us. They function in a certain way as a key, prepared to fit only in the locks that are on the cells of its host and not in any other. Without these peplomers the virus would not be able to recognize its host and would end up dying.

External and internal structure of the 2019-nCoV which means (Glycoprotein Spicule, Protein M, Hemagglutinin Esterase, Envelope, NRA and N protein, Protein E)

External and internal structure of the 2019-nCoV which means (Glycoprotein Spicule, Protein M, Hemagglutinin Esterase, Envelope, NRA and N protein, Protein E)

So could we bend those “keys” or cover the “locks” in any way that makes it impossible for them to fit? Altering these proteins is precisely the key to many of the antiviral treatments that are in use today. It is a matter of time to find a way to block that same mechanism in the coronaviruses, thus preventing it from joining our cells.

On the other hand, viruses reproduce by getting the cell of their hosts to make copies of their genetic material, over and over again. They alone cannot do it, so they take advantage of all the cellular “machinery” that we have developed. Specifically, in the case the coronaviruses produce a huge protein that needs to be divided into pieces so that each one gives rise to a different structure of the virus, such as a cut-out. These cuts are produced by the action of the so-called proteases and we know how to block them. It remains to find a way to apply it specifically to the new coronavirus and thus prevent it from building the pieces that make it up.

To these lines of research is added the search for a vaccine, which is something even more complicated, due to the rapid rate at which coronaviruses usually mutate, causing antibodies to not recognize new strains, as with the flu seasonal.

The August of Pseudotherapies

While scientists and doctors work piecework to prevent the outbreak from becoming more complicated, there are those who take the opportunity to make August selling empty promises. Many pseudotherapists have used the situation as a hook and claim to have the cure, which ranges from leaves with no effect to shots of bleach. It is true that it is not the same bleach with which we scrub our houses, it is an industrial variant (sodium hypochlorite), which, being highly oxidizing, chemistry also calls it “bleach”. We talked about the sadly famous MMS (sodium chlorite) that has already claimed some lives and too many medical complications. This product is recommended only to disinfect surfaces, not living tissues such as our digestive tract.

Meanwhile, some stars of media medicine add to sensationalism. They suggest that China lies and there are between 10 and 100 times more cases than we are told. Given that 100 times more cases would make more than one million affected, it becomes very difficult to believe. A deontologically reprehensible alarm that every healthcare professional should avoid. Especially, when the information we have does not depend entirely on the Chinese institutions, but on a multidisciplinary mission sent by WHO, which is in Wuhan investigating the real impact, as well as the origin of this outbreak.

So we can be calm. Alert but calm. Scientists, politicians and especially health workers are doing everything in their power to stop the new coronavirus. There is no reason to panic, because we are in the hands of perfectly trained professionals whose job is precisely to constantly monitor these situations, both when they reach the press and when they do not.

DON’T KEEP IT UP:

  • The data given are not of the gross mortality rate (Proportion of people killed in relation to the total population) but of lethality (Number of deaths from a disease in a specific period with respect to the number of people infected by that disease during the same period)
  • It is not contraindicated to travel to China or stop trade with it. There are regions of the country with less infected than some European countries. Only flights to areas with a large number of affected should be restricted. Likewise, Spain is relatively isolated because it does not have airports with direct flights to the most affected areas.
  • It doesn’t matter what the influencersThis is not a biological weapon and there is no place to talk about conspiracy. And, of course, neither the MMS nor the rest of the alternative treatments are able to eliminate the coronavirus or cure any disease.

REFERENCES (MLA):

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