From the history of influenza

From the history of influenza.  Drawing from the site www.sciencephoto.com

The diagnosis of "flu" has already become a habit. Temperature rises, pouring from his nose, sore throat. Nothing is done, will have ten days to sit at home, swallowing the bitter pill and choking with milk and honey. But it's not fatal. Are you sure? Less than a hundred years ago by a flu epidemic killed nearly 40 million people. There are doctors is a sign: "If you came cold, so not far offepidemic flu ". All medical publications are beginning to publish articles on the prevention and vaccination, and the district doctor to prepare a plump pile of hospital sheets. This is not surprising. These days, every year during the flu get sick more than 15% of the total population.

"Star" epidemic

The first information about the flu are 412 BC. It was then that the greatest physician of antiquity Hippocrates described the disease that is very similar to the flu. In patients dramatically increased temperature, headache and muscle pain appeared in the throat. In this case, the main feature of the disease was an incredible contagious. If you get ill at least one person, a couple of days ill dozens or hundreds of people a week. Was there a real epidemic. The most extensive of them covered the whole country, and sometimes even continents, it is such an epidemic and recorded in the annals of history.

In the Middle Ages outbreaks were not uncommon among the people for it even invented a special name "Italian Fever". Fever with the flu from the heat, and many have sinned in the sunny Italy, assuming that's where the source of infection. State of medieval medicine left much to be desired: people sneezing, coughing, some have died, and doctors could do nothing to help them. As the treatment of patients received only drinking plenty of fluids, infusions of herbs and honey.

What is the cause of a mysterious epidemic? — Doctors and philosophers have speculated. In some countries in this regard were his explanations. In Italy, for example, believed that to blame the special position of the stars and the moon. But the Germans have paid meticulous attention to the disease comes in the winter, and suggested that to blame pickled apples and salted fish, the main "winter" food. The general opinion stated: "all God's will." It was believed that the epidemic — the punishment for sins, and we can only pray to God that spared the disease. However, such prophylaxis was not too effective.

In historical documents preserved mention of the major flu epidemics in 1510 and 1580. Last made so indelible impression on his contemporaries that her details recorded in the chronicles. Thus appeared the first rigorously documented description of the influenza epidemic. By XVI century disease already been described in detail, but still remained nameless. Its first official name of the disease was in the same century in Italy. It was called "influenza." Regarding the origin of the word, there are several hypotheses. According to one of them, scientists, desperate to find the cause of the disease on the ground, began to look for her in heaven. Astrologers have suggested that the appearance of the disease is due to the influence of the stars. When the heavenly bodies are arranged in a specific sequence, to mankind falls epidemic. The word "influenza" in Italian language means precisely that "the influence of the impact."

Another hypothesis for the origin of the disease name is not as poetic. When scientists noticed that epidemics occur during the colder months, it suggested that the reason for that — the impact of hypothermia. The word "influenza" and then had the way. Another official name of the disease — "flu" emerged three centuries later. And if the name "influenza" is associated with the causes of the disease, the word "flu" (from the French word "gripper" and the English "grip" — catch) indicates its symptoms. The disease begins suddenly and dramatically, people in just a few hours is as if caught disease.

Chinese "Spanish flu"

Influenza epidemics occurred quite often, but the nature of global disasters have taken three or four times in a century. Such large epidemics are called pandemics. Known pandemic in 1580, 1675, 1729, 1742-1743, 1780, 1831, 1857 1874-1875 years. For many centuries, scientists have accumulated a lot of information about the flu, but to understand its nature was still very far away. Why is there a flu epidemic, why there are times in 30 years, and how, in the end, it treated?

Above the cause of flu doctors continued unsuccessfully to fight until 1889. Theories of influenza constellations and pickled apples have long outlived their usefulness, but the new, more progressive. Scientists have tried to link the outbreaks with pathogenic influence of the electric field of the Earth, variations in temperature and changes in rainfall. Some experts thought about the impact of ozone in the air, on the occurrence of epidemics. There was even a suspicion that influenza — an early stage of cholera.

End of fantastic theories put German physician Richard Pfeiffer. During the epidemic 1889-1892 year from the sputum of patients it has allocated an extremely small bacterium, similar to the wand. Is it caused the flu? Opening Pfeiffer confirmed the study of French and German scientists. The scientific world was celebrating the victory: finally known to cause flu, is a bacteria — bacillus Pfeiffer! However, antibiotics had not yet been invented, and treat influenza, as before, there was nothing.

The next influenza pandemic occurred in 1918 at the end of the First World War. Back then, no one suspected that this would be the worst pandemic in human history, and it will take several times more lives than any military action. Contagious, deadly flu got a special name "Spanish fever". Paradoxically, the birthplace of "Spanish flu", according to scientists, was China. The first fatal cases of the disease have been described by doctors in the United States in March 1918 and in the port cities of France, Spain and Italy in April 1918. About Chinese origin influenza, few knew, but he could well be called "American" or "French". However, the military censor banned all publications of the epidemic, so the first mention of it appeared in Spain, which did not participate in the war.

For ten months, "Spanish flu" spread throughout the world. This was the first wave of the pandemic, for her came second and third. In two years, the flu killed 20 million people, and according to some reports, the figure was 40-50 million, ie 2.5% of the population. The disease developed at lightning speed: in the morning a man was healthy, the day temperature rose, and the evening was pronounced dead. Those lucky enough to survive the first day of the disease, often later died from flu complications, such as pneumonia. According to statistics from the "Spanish flu" has been hit almost one-third of humanity. In addition to high mortality disease had another peculiarity: it is only the adult population is decimated. Old people and children, who were usually the main target of flu, this time proved invincible.

The Holy Trinity

The deadly "Spanish flu" scare doctors. If earlier it was believed that a healthy body is able to cope with the flu, but now the question of the prevention and the search for drugs got serious. Doctors have doubts about the nature of the bacterial flu. After all, if the disease was the same stick Pfeiffer, why "Spanish flu" so different from previous flu epidemics?

The answer to this question was found only in 1931. American Richard Shope, studying influenza in pigs, found that the disease is not caused by bacteria and virus! Perhaps the
human flu caused by viruses? This hypothesis was breaking all existing ideas about the causes of influenza, and some scientists have received her with hostility. However, research has continued, and two years later, the virus that causes flu in humans (Orthomixovirus influenzae), has been opened. In 1933 in London, scientists at the National Institute for Medical Research Wilson Smith, Christopher Andrews and Patrick Laidlaw first isolated the human influenza virus, which has been called "type A influenza virus." The history of discovery is quite fun. In 1933, in England there was a epidemic flu, and scientists take this opportunity to set a goal to find an animal that is sensitive to human influenza. The experimenters were challenged all the animals were able to get, from snakes and ending with various rodents, and after some time checking health of their wards.

Time passed, and the animals were not going to hurt. Scientists almost desperate and were ready to conclude that the human animal influenza is not transmitted, when they were lucky. Bypassing again vivarium, they noticed that one of the ferrets looks unhealthy. When the Laboratory Wilson Smith took the animal in his arms, ferret sneezed. It turned out that the animal is sick, but what? Imagine the surprise of scientists, when two days later Smith himself has the flu. It was the first case in the history of experimental infection with influenza, it was during this study had a pathogen of the disease — influenza virus type A.

It seems to be the causative agent of the disease is found, but in 1940, the scientific world is another shocking discovery — Thomas Francis allocates another influenza virus type B, and in 1947 Richard Taylor opens the influenza virus C.Today, these viruses are known to many. Influenza A virus often leads to moderate to severe disease severity, and cause illness not only in humans but also in some animals: horses, pigs, ferrets, and birds. All severe epidemics and pandemics are caused by the virus. Type B virus infects only human, most children do not cause pandemics, and is usually caused local outbreaks and epidemics, sometimes covering one or more countries. The influenza virus from other less studied. It infects only humans. Symptoms of the disease usually very light, or do not appear at all. Flu Type C does not cause epidemics and does not lead to serious consequences.

After finally revealed that the influenza germs — viruses, many mysterious facts about the history of the disease has become possible to explain such variability and contagious. That's just the problems have not diminished. How to find a cure for the flu? After all, virus, unlike bacteria, can not be called a full body, it is as if the border of the living and non-living, so it is impossible to kill. All that is in the virus — a chain of nucleic acids to the genetic information, and containment. Only infiltrating into the wrong cells the virus can exist. With special structures on its surface is attached to thehost cell and then gets inside, where he began to dictate the rules. The nucleic acid of the virus integrated into the DNA of healthy cells, and cell damage, together with its protein begins to synthesize a large number of viruses. Newborn viruses come out at will and looking for a new owner, and their host cell is doomed to failure.

The influenza virus operates on the same principle. His target — the cells lining the respiratory tract: the mouth, nose, trachea. It was there after infection airborne or contact-household by being introduced and there multiply intensely viruses. Yet the person feels healthy, is called the incubation period. It lasts from6-12 hours to 2 days. Then begins toxic effect of viral infection. The man abruptly ill. He may appear runny nose and sore throat. By this time, a great many virus enters the bloodstream and spreads throughout the body, acting primarily on the nervous system and the brain. The patient begins to feel weakness, headache, fever him.

The next step — viruses capture the entire body, affects the heart, brain and lungs, etc. All flu complications arise because of such a common infection, and because of that weakened body begin to attack various pathogenic bacteria. Depending on the patient's immune system flu can last from one to several weeks. During this time, the body's defenses and destroy all viruses cope with the consequences of the disease. At first, this process is slow, and only when the immune system is trained to recognize the viral particles and begin to create a special protection against them, the fight against the virus becomes more efficient. Such immunity to the flu lasts for many years.

The elusive face

It seems to be ill with the flu at least once, you can not be afraid to pick him, butluck and manifests cunning viruses. Year after year, they are changing! Of course, their "content" remains almost unchanged: the flu does not cease to be the flu. Masked only the surface of the virus, but it is enough that the immunity of its "do not know" and the man fell ill. These changes can be explained by the fact that going from person to person, virus undergoes mutations. This process is called antigenic drift, scientists, during his change slightly antigens — substances from the surface of the virus.

The result of this drift are the annual flu epidemic. They are rarely fatal, because partial immunity to the modified virus in humans is available. The worst epidemics and pandemics occur every20-40 years, when out of nowhere appears a virus with mutations so severe that the immune system does not recognize, and the body is vulnerable to disease. Those mutations may impart additional properties virus, for example, for ultrafast disease. Scientists call such a change in the virus antigenic shift. The most popular theory antigenic shift states that the emergence of the "evil" of viruses linked to mutations of the influenza virus in its transition from human to animal and vice versa.

Question: "Where does the flu virus, and where he is hiding between epidemics?" Asked yourself many researchers. The only thing they were able to establish: the virus is circulating in the Southern Hemisphere to the North and back. Inautumn and winter months it is in the north,spring and summer— In the south. And throughout the year, outbreaks of influenza occur near the equator. Perhaps there is the birthplace of the flu.

Some scholars suggest that the break between epidemics dormant virus in birds and animals. This is only a hypothesis, reliable evidence yet. Despite that in1940 Years were first vaccine designed to instill human immunity to influenza virus, cure disease, scientists have not been able to invent. The history of influenza pandemics continued. 1957-1958 years — from the Far East came to "Asian flu". Only in the United States died from it 70 thousand people. 1968-1969 years — the "Hong Kong Flu", the elderly and children suffer. The death toll nearly 34,000 man. 1977-1978 years — the "Russian flu" is relatively light.

By now been almost thirty years since the last flu pandemic, and apparently just around the corner next. Doctors around the world are in suspense and constant combat readiness. We can only just in time to chop the flu vaccine, hoping that the scientists from the WHO guessed right strain of the virus coming. Stock up in case of illness rimantadine. To lift the immunity of interferon and vitamins. And hope that already in the XXI century anti-influenza drug is bound to be invented.

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