Where do dangerous coronaviruses come from?
It is believed that the strains that caused SARS, MERS and the current outbreak did not originate in humans but in animals.
Although many animals carry dangerous viruses, they are usually not transmitted to humans - fortunately for us.
"In most cases, there is a species barrier that the virus cannot overcome," said Professor Andrew Easton of the School of Medical and Biological Sciences at the University of Warwick.
"But sometimes, if a person has immunodeficiency or there is some other important factor that will open the way for the virus to the body, you can get an unusual sporadic case (infection. - Ed.)," - says the scientist.
The danger often begins with an unusual mutation.
"Usually there have to be some changes that will allow it to grow in the body of the new host," explains Professor Easton.
In these rare cases, when the coronavirus is still transmitted to humans, the situation can be very serious.
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It is worth noting that not all coronaviruses are very dangerous - people are constantly exposed to less harmful types. But it is those that are transmitted from one species to another that pose the greatest danger.
Why are they so dangerous?
"When a virus jumps from one species to another, you can't predict how it will behave, but it often happens that if it finds a niche in a new form, it can be quite serious in the early stages of the process," says Professor Easton. .
This is because when the coronavirus suddenly jumps from animal to human, our immune system has never encountered the strain before, so we can be very vulnerable.
The same thing happens when flu viruses migrate between different species.
"With pandemic influenza, which is transmitted from waterfowl to humans, the problem is that when the virus makes this leap to humans, the course of the disease will be severe," explains Professor Easton.
It is believed that the worst outbreak of influenza (1918-1919), which killed up to 50 million people, was caused by a virus that spread to humans from birds.
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There is no indication that the coronavirus will be as deadly, but the history of previous serious outbreaks caused by the virus from animals to humans is a matter of serious concern to the medical community.
Can coronaviruses spread quickly?
Usually, the probability that a virus that has been transmitted from animals to humans will be able to be transmitted from person to person is low - at least in the early stages.
"It's another barrier, another hurdle he's going to have to cross," says Professor Easton.
But the situation can change quickly, and when it does, it can be very serious.
A mutation in the virus can allow it to spread from person to person, meaning it will spread much more widely and much faster.
This is exactly what happened during the current outbreak in China, and therefore measures are being taken to combat the spread of the disease.
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However, how easily it is transmitted has not yet been definitively clarified.
According to Professor Easton, people with reduced immunity are more vulnerable to the virus, while healthy people may be resistant to it.
"Some viruses are very easily transmitted and some are extremely poorly transmitted. One of the questions to be answered is where is this new coronavirus in this range," he said.
What can be done after the onset of a coronavirus outbreak?
The bad news is that medication is often not the answer.
"There are very few effective antiviral drugs," warns Professor Easton.
However, there are other measures that can be taken - in particular such simple things as washing hands and using handkerchiefs.
"Basic hygiene is very useful. It protects against all sorts of things, and it's probably the only weapon available right now, because you shouldn't count on a cure for the virus in the near future," said Professor Easton.
In addition to prevention, the government's actions against infected people are also important.
"Another aspect is to identify infected people as soon as possible so that they can be treated and ideally treated to reduce the likelihood of the infection spreading," he said.
Fortunately, after the previous outbreaks of coronaviruses SARS and MERS, international systems of measures were introduced.
The global medical community hopes that the lessons learned from previous coronavirus outbreaks will make current and probable future incidents less dangerous.