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© Georgi Kozhukharov
The German city of Frankfurt is one of the places from which the coronavirus was imported into Bulgaria, and the rest will become clear in the coming months. This is the conclusion of a detailed study of the coronavirus in the country, carried out at the National Center for Infectious and Parasitic Diseases. Contaminated SARS-CoV-2 samples were selected for this purpose (The virus that causes COVID-19), grouped from different parts of the country, taken during the first four months of the epidemic in Bulgaria.
For “Dnevnik”, popular science explanations in genetics were given by molecular biologists Associate Prof. Ivaylo Alexiev and Associate Prof. Ivan Ivanov. They are part of the team involved in the study and run the national reference laboratories for HIV and antibiotic resistance, respectively.
Why do we know it is from Frankfurt?
Scientists group the samples together and call them clusters (from English: group – author’s note), because it is assumed that those infected from the same place, at approximately the same time, will have the same source of infection.
“We have several separate Bulgarian groups, of which we assume that at least one of the sources came from Germany, rather than Frankfurt. It’s just that the genetic makeup of the introduced virus is very similar to the genetic makeup of the viruses that were isolated in Frankfurt “, says associate professor Ivan Ivanov and specifies that for the other groups of samples it remains to be clarified where they brought the virus.
According to him, it should not be deduced from this fact that a Bulgarian went to Frankfurt or a German from there came to Bulgaria and thus the virus was transmitted. “They may have met at the airport, there may be an intermediary, the patients may have met on skis in Austria without suspecting the encounter. It’s just that the virus, which is isolated in Germany, is the most genetically genetic in Frankfurt “. close to the one that was imported and discovered in our country and is basically to be imported into Bulgaria ”, adds the associate professor.
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On February 18, a group of German doctors published a letter describing as a “failed attempt” the preliminary examination of the symptoms of return on February 1 by a military plane of 126 people flying from Wuhan to Frankfurt. Two of the passengers tested positive for SARS-CoV-2. Flight suspensions and border closures began in Europe in mid-March. A little later, the German media wrote that the infection may have entered the country first through Italy, but later it became known about the outbreak in the Austrian town of Ischgl, which closed only on March 14.
Interestingly, molecular biologists continue to search for additional patient information collected from the Regional Health Inspections (RHI). These are the so-called epidemiological data and are a survey of those infected where they were recently and who they met. Information must be detected to determine if there is a clear link between genetic information and the human narrative.
© Georgi Kozhukharov
Scientists do not rule out the possibility that the contagion with SARS-CoV-2 occurred before March 8, when the first cases of coronavirus were registered in the country, but they were not detected because a person “had symptoms similar to those from the flu, she was not seriously ill and has stayed home to be cared for, ”explains Associate Prof. Ivaylo Alexiev.
The virus as a family tree
Bulgarian scientists know exactly what the coronavirus is in Frankfurt, because they compare the country’s data with information from the World Genetic Bank. Microbiologists Compare Coronavirus Spread Around The World To A Family Tree That Has Thousands Of Branches (This is a pandemic after all – author’s note), but each terminal branch has a connection to the initial one.
“The Chinese strain in Wuhan is the first. The Thai and Japanese strains come from it, two more branches come from the Thai, and so on. Generally, in Europe, the Bavarian strain that comes from China is considered the first.” Ivanov said. “When the genome changes, it is called a mutation, and these mutations introduce a bioinformation program that can calculate the evolutionary path of viruses,” added associate professor Ivaylo Alexiev. (Video with the evolution of the coronavirus around the world see at the end of the article)
Who infects the most
At present, there is evidence that the genetic characteristics of the coronavirus are relevant in determining whether it is easily transmitted: “It has already been discovered that a certain genotype of the virus is transmitted more frequently and is prevalent in Europe, including Bulgaria, in the United States. , and now in Asia “, explains Associate Prof. Ivan Ivanov and says that in the country the mutation came from various places. This is quite logical, given that the pandemic is unfolding, travel is limited, but it does not stop. And this allows the infection to spread from asymptomatic carriers.
© Georgi Kozhukharov
The researchers explained that for now, the different genotypes of the coronavirus have nothing to do with whether the disease will be severe. The genetic characteristics of each individual are key: “Rather, the difference is in people who have many more receptors to which these viruses attach, and other people have fewer receptors. Those with more receptors would theoretically become more infected. violently “, explains Associate Prof. Ivaylo Alexiev and adds about the importance of the immune system, which” decides to attack the virus. ” These receptors are found on the surface of human cells and have an important function for various human organs, but viruses also attach themselves to them.
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“The receiver is a lock. Imagine you have a building with many doors and locks. If you have the correct key, it opens and enters and infects the room. If the lock does not match the key, the virus cannot enter the room and infect, “he said. metaphorically Associate Prof. Alexiev. In his metaphorical example, the room is a human cell, the receptor is a lock on a door, and the spikes of the virus are the key.
According to microbiologists, it is not unequivocally proven that more viruses in the human body lead to a more severe course of the disease. Scientists again point to everyone’s genetic characteristics: “Even if there are many viruses, if there are not enough receptors to catch these viruses, they disappear,” says Professor Ivanov. “Also, the immune system reacts in a complex, cascading way and it can be easy, maybe difficult,” added adjunct professor Alexiev.
While the coronavirus
When asked if SARS-CoV-2 will go away because the virus weakens from person to person, the two microbiologists say no. “At first we thought it would be exactly like this, following the course of other similar viruses. With human-to-human transmission to reduce their pathogenic potential and increase their transmission, this is the natural course of viruses: kill less, on the other hand, It should be easier to spread. There is no such moment here, “Associate Professor Ivanov said. Therefore, scientists believe that the way to overcome the pandemic is to develop a vaccine.
“Now, the possibility of viruses is that we often travel and in just 24 hours, if a virus appears in one part of the world, in a week it is everywhere,” said associate professor Ivaylo Alexiev. According to him, epidemiologists, microbiologists, virologists “knew that a pandemic would occur” because rarely, but periodically, emerging viruses mutate so that they can be transmitted from person to person.
“A virus that is characteristic of the animal kingdom can be transmitted to a person and make him sick. A person will get sick, but he will not transmit it to another, it is very difficult. But the moment the virus mutates so that it can be transmitted from person to person, then a new pandemic can occur. The HIV virus originated in a similar way, “explains Associate Prof. Ivaylo Alexiev. (For previous coronaviruses, here)
What you need to know about the coronavirus
