As there are viruses and epidemics, what are the mechanisms of infection and whether the virus higher purpose? Epidemiologist, doctor of medical Sciences Mikhail Favorov answered the most important questions for “RBC”.
Coronavirus is cause to make fun of a stranger, he dedicate memes about him compose songs. The virus enters not only in the organisms of living beings, but in pop culture. But time will pass and everyone will forget, as once stopped talking about the Ebola virus, SARS, and smallpox.
In 1980-ies in Central Asia experiencing the outbreak of a previously unknown virus. The situation was difficult and tense. The virus is transmitted through contaminated water. Due to its use the number of patients was increased dramatically. In most cases, the disease proceeded relatively well, but the horror is that they died mainly women in the third trimester of pregnancy.
Began a comprehensive study, during which was opened the virus of hepatitis E. Its main manifestation is “jaundice”. Now there is a vaccine and the various methods of prevention of this infection. Then in the midst of events worked as epidemiologist Michael Favorov.
“I have repeatedly been at the center of epidemic outbreaks in Africa, Asia, and India. But that, in the city of Dashoguz in Northern Turkmenistan, was perhaps one of the most difficult and intense. Remember, we launched a 30-bed intensive care unit for critically ill pregnant women. This epidemic is reminiscent of the situation during the war, only war is the epidemic of injuries, but here’s a struggle with an invisible enemy,” — says said.
Today Michael Favorov lives in the USA, is President of the company DiaPrep System Inc and continues to work actively in the field of diagnosis, control and prevention of infectious diseases.
Virus — the simplest form of life. It is considered that if it is inside a human or animal, it becomes a living creature multiplies and exchanges information. But when the virus is outside the body, it is considered nonliving. About viruses we’ve learned recently, about 100 years ago.
Biologist Dmitry Ivanovsky published a study about the existence of some substance which passes through filters, check bacteria, and called it a virus.
While the plague known to mankind for thousands of years, she’s a different nature — it is caused by bacteria that are more complex and larger organism. Its spread was associated with a low standard of living and poor hygiene. The percentage of mortality reached 25%, that is, with the pulmonary form died every fourth.
Among viral infections, the worst was smallpox, which has affected all countries of the world. It was called smallpox. The vaccine was able to devise thanks to the random acquaintance with cow pox. Virus animals that were carriers injected into the human body, but not vaccinated became ill with the human form of the disease: the body is defended antibodies of the introduced virus.
The uniqueness of smallpox that is anthroponosis virus — they were just sick people. So when I produced a vaccine, smallpox has been eradicated. In 1950-ies in Africa have been vaccinated the last contact with the sick, and in 1978 the virus was completely eliminated. Smallpox disappears when the last of the sick have antibodies, he recovers and ceases to be a carrier.
Another thing is that the main part of viruses are zoonotic, that is transferred from animals to humans, and to completely eradicate such a virus is unlikely. His first transmission from animal to human is called crossweave transition. So, all known influenza virus were first moved birds, and only during the First world war was a transition to the human population that is causing the epidemic of “Spanish flu”, which died tens of millions of people.
Over the past 20 years, we have seen already a third attempt of the transition of the coronavirus in humans. The vaccine, of course, will be found, said Michael Favorov, but do not expect that the “transitions” of mers and other zoonotic infections will stop, even with improved medicine.
Recipes with a bat
“To take one’s bat and cook in boiling coconut milk for about 15 minutes with onion, carrot and spices” — it is the apocalyptic soup recipe, one of many Chinese delicacies.
Bats in China are sold dried and used as a means of alternative medicine. It is these beings caused the outbreak of SARS (SARS) in 2003, the fever of the Ebola virus in 2014 and coronavirus COVID-19. The Steven Soderbergh film “Contagion” perfectly illustrated the chain of coincidences that led to an epidemic-like outbreak of deadly Nipah virus in Malaysia in late 1990-ies. All started well with the bat, the virus moved on to pigs and then to humans.
“Outbreak of epidemics is not just a coincidence, but a coincidence, says Michael Favorov. — And they are all caused by changes in the environment. Humanity has never been in contact with bats close enough, suddenly reached into the cave and caught them. Then the mice brought into a place treated may people even slept in the same room. Zoonotic infections are typically transmitted under two conditions: a high dose of the pathogen and fairly close contact. Another incentive may be that this year the mice were so-called epizootic is an outbreak. This means that a person got a large dose of millions of virus particles. Among these particles there is always variation, which is attached to the receptor in the human body and gets inside your cells. And first contact is the hardest and often leads to the death of the first infected, because all the system and other enzymes, the virus is not adapted absolutely to the man and quickly leads to the destruction of the body. Themselves mice don’t get sick, and are just carriers”.
The level of population density China and India surpass all other regions of the planet, and the variety of animal species in Africa is so great that most of us are hardly aware of the existence of some of them, such as the Okapi, fiverr, rokonok.
As rare animals, and population density provide additional incentives to the high speed of the spread of infection. The virus does not affect separately the Chinese and other Nations, viruses are apolitical and have no religion. They are able to adapt to any changes in the environment better than humans. All they need is warm bodies and possibly certain receptors.
Coronavirus can be called a kind of Agatston the disease in rare cases, affected children, and die mostly elderly people. One of the theories put forward by experts suggests that there is a receptor that appears only in adults.
This “treacherous” receptor helps the virus attach to the cell in large volume. But this is only a hypothesis, and to confirm it, you need to do a lot of work for the study of viruses. Their structure is complex and diverse. Viruses vary in shape, according to the replication mechanism (destruction of the body), but the biggest difference is that part of the virus has the nucleic acid is DNA and the other portion contains RNA. These are two different “nature”, and the difference between them is much greater than between elephants and bacteria — and both at least have cells that contain DNA.
The outbreak of epidemics is not just a coincidence, but a coincidence.
Each virus has its own feature, which he uses to advantage on a living creature, and this interaction depends on the consequences of the disease. If a virus is “our”, anthroponomy, global epidemics, as a rule, is not (with rare exceptions the same smallpox). It causes the disease, which leads, for example, to chronic disease like hepatitis B and HIV. If a virus is zoonotic, it somehow leads to an outbreak.
Everything is closed: the market, shops, metro. Public transport is completely empty. On the sidewalks floats just debris blown by the wind, disappearing into a yellowish haze. Strange when you consider that the city is home to millions of people. Occasionally on the street there are people in respiratory masks, some made from scrap vehicles.
Once seeing such a picture, it is hardly possible to confuse with anything the epicenter of the spread of respiratory diseases, and need to be protected immediately.
“Methods of protection against virus in global and local sense, depend on the spread of the virus and what is its nature, — explains Mikhail Favorov. — During the outbreak of hepatitis E virus is transmitted through water, so it was deemed appropriate to stop any contact with water. When there is a respiratory outbreak, as of now, it is more difficult to control. The Chinese did very well: they isolated big city. It is an ancient proven method of combating the epidemic, which was found in the Middle ages, when fighting with the plague. You need to wait until people have been ill or “promassiruyte,” the virus has the ability to adapt and ceases to show symptoms, while the human body produces antibodies against it. When people with antibodies will be over 30%, we can say that the epidemic will soon end.”
To protect yourself and your family during respiratory epidemics, the main thing — to be no closer than 2 m from a sick person, sneezing or coughing person, wash hands every two hours to ventilate the room with minimal human contact.
“Respiratory mask may protect you, but the problem is that it is reliable in just 20 minutes,” recalls said.
The arms race
Human history consists of tens of thousands of bloody wars, but the worst loss is probably the war with parasites. According to some, the plague died more people than all wars taken together, about 186 million people. From one of Justinian’s plague, the first recorded in history, killing 100 million people.
To develop protection against biological threats is costly, so vaccines are created only for those viruses, which pose a real danger. Moreover, some vaccines, the viruses used, become sustainable and alter their structure, so mankind have to constantly be alert and come up with something new.
The respiratory mask may protect you, but the problem is that it is reliable in just 20 minutes.
In Microbiology it is called arms race between a virus and a human when the virus gets used, and the person develops a more sophisticated form of the vaccine. This can be attributed to the influenza virus able to constantly change its antigenic structure, escaping from the immune system or vaccines.
For example, initially had influenza a, which was invented vaccine. But microscopic creatures, or rather their nucleic acid, picked up the key to existence in the body. So there was a flu type B. But not all viruses can “decode” the vaccine. For example, the measles virus to which there is a vaccine that has not changed for centuries and can’t survive in the body in the presence of antibodies.
The highest goal
In biology class we were told that life is the mode of existence of nucleic acids. One of the variants of existence of nucleic acids of the viruses that live on other organisms.
They do not care about our welfare, they are trying to adapt like all living beings on the planet. The only thing that should be thanking them — an evolutionary perfection of the human immune system. For centuries, when there was any contamination, the human body has developed antibodies and formed cellular immunity.
Everyone knows that if you keep a person in a sterile environment, and then leave, he will die because he will not have the mechanism to develop protection. But it is not the purpose of the existence of viruses, but rather a side effect.
To predict the occurrence of outbreaks of virus more difficult, than to talk about higher sense. It’s always a unique situation that occurs as a result of changing the state of the environment in which a person experiences a new environment of interaction with other species.
And today the human impact on the environment has reached absolutely incomparable scales in comparison with previous generations, besides the human species is constantly growing. Scientists have the opportunity to observe the attempts of viruses to make the transition crossweave due to laboratory methods for tracking.
Doctors have eradicated smallpox and almost defeated the polio virus — it inspires the hope that a new virus will be possible at least to negotiate. No matter how developed these relationships, it is worth remembering: as long as people will exist as a species, there will always be those who want it parasite.