The world regularly experiences outbreaks of plague, cholera, Ebola and various new types of diseases like MERS. In Madagascar, for example, plague epidemics occur almost every year, claiming dozens of lives. The 2010 cholera epidemic in Haiti killed 4,500 people. The latest Ebola epidemic is responsible for more than 11 thousand lives. The current MERS epidemic in South Korea has already claimed the lives of nine people.

An outbreak of Middle East respiratory syndrome (MERS) coronavirus has occurred in South Korea, making it the largest outbreak of the disease outside the Middle East. There are 108 known cases of infection and nine deaths. More than 2.5 thousand people were quarantined, and more than 2 thousand schools were closed.

MERS was first discovered in Saudi Arabia. Children and the elderly are at risk - they usually suffer from weakened immunity. One of the victims of the virus was an 80-year-old man. Among the sick are teenagers.

According to the US Centers for Disease Control and Prevention, MERS affects the respiratory system - the lungs and airways. Patients suffer from high fever and cough. Then it becomes difficult for them to breathe. In some cases, MERS leads to diarrhea and nausea. The disease can lead to severe pneumonia and kidney failure. On average, every third or fourth patient out of ten die. However, the disease can be mild or asymptomatic.

The virus was first discovered in 2012 in Saudi Arabia. However, it later became known that a resident of Jordan had previously suffered from the virus. MERS was brought to South Korea by a local resident who returned from the Middle East. writes The Wall Street Journal. His illness began with a slight cough.

Most likely, the virus is transmitted through the secretions of sick people, for example, during coughing. But so far the routes of transmission of infection are unknown. The disease is transmitted mainly through close contact, for example, if you live with a sick person. Hospitals are especially vulnerable - you can easily get infected here.

This is far from the only epidemic that has occurred in recent years. The most famous epidemic was the Ebola outbreak, but over the past few years humanity has also suffered from outbreaks of plague, cholera, antibiotic-resistant tuberculosis and other diseases.

Ebola fever

Last year, the world was hit by one of the largest outbreaks of Ebola. The press has stopped actively discussing the epidemic, but it continues: in Africa, people are still getting sick with fever. Outbreaks of fever occur almost every year, but rarely spread outside of Africa. True, this time the sick people were among residents of Europe and the USA.

According to the World Health Organization, as of June 8 this year, this outbreak has killed more than 11 thousand people.

According to many experts and politicians, the latest Ebola outbreak has shown that the global health system is simply not ready for a global pandemic. Ebola fever turned out to be not so contagious: the virus is not transmitted through the air. If a new, more contagious disease emerges, it will be nearly impossible to contain.

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EPIDEMIC
a significant increase in the normal incidence of any disease or pathological condition among the population. An epidemic is also called a sharp increase in frequency certain disease followed by a decline in a relatively short period of time. For example, before the advent of the measles vaccine in 1963, measles, spreading through the population and affecting susceptible individuals, gave rise to wave-like increases in incidence. The outbreak was followed by a period with a relatively small number of cases. Diseases with this form of the epidemic process are most often infectious, i.e. transmitted from person to person or from animals to humans. In the 20th century It’s even difficult to imagine the physical and moral suffering that epidemic diseases brought to the population in the past. In medieval Europe they were the cause of death of every fourth person. Epidemics today are generally not as widespread and deadly as they were centuries ago, but they nevertheless continue to occur as a consequence of disturbances in the established balance between human populations, their conditions of existence, and the presence of infectious disease agents.
Main reasons. An epidemic occurs when a pathogen spreads through a susceptible population. The intensity of the epidemic process is influenced by many environmental factors. Susceptibility to infection is characteristic of those populations that have not acquired immunity through previous contact with the pathogen of this disease. Immunity occurs not only as a consequence of a previous illness, but also after vaccination with drugs containing antigens of a specific pathogen. Occasionally there are examples that infection with one pathogen can protect against infection caused by another; Thus, infection with the cowpox virus protects against smallpox. Depending on how the infection spreads, susceptible populations can be protected by excluding their contact 1) with already sick individuals; 2) with pathogen vectors, such as mosquitoes, fleas or lice; 3) with objects that transmit infection, for example water, which may be contaminated with a pathogen; 4) with animals that serve as a reservoir of infection, such as rats.
Endemic diseases. If an infectious disease constantly occurs among the inhabitants of a given area, then any newly arrived susceptible settlers coming into contact with the general population will soon be infected, especially in childhood. Since every at the moment only sick small part population, there are no significant fluctuations in incidence, and its consistently stable level makes it possible to classify this infectious disease as endemic for the population of a certain area.
Pandemics. If the population of any part of the world is freed from contact with a given infection for a long time, the number of people susceptible to the corresponding pathogen increases significantly. Once an infection appears, it can almost simultaneously affect the population of large areas, causing mass epidemics. This spread of the disease is called a pandemic. A similar process is also possible when a susceptible population encounters a new infectious agent, as happened with the spread of the influenza virus in 1918.
MAIN EPIDEMIC DISEASES
Having observed a bewildering variety of deadly fevers over the centuries, medical scientists have tried to link typical patterns of infectious diseases to specific reasons, in order to identify and classify diseases on this basis, and then develop specific methods to counter them. Considering the evolution of our knowledge about some of the main epidemic diseases, we can trace the formation modern presentation about the epidemic.
Plague. In the Middle Ages, plague epidemics were so devastating that the name of this particular disease figuratively became synonymous with all sorts of misfortunes. The successive plague pandemics of the 14th century. killed a quarter of the then population of Europe. The quarantine isolation of travelers and arriving ships was futile. It is now known that plague is a disease of wild rodents, particularly rats, which is transmitted by the flea Xenopsylla cheopis. These fleas infect people living in close proximity to infected rats, the reservoir of infection. With bubonic plague, transmission of infection from person to person begins only with the development of the highly contagious pulmonary form of the disease in the patient. At the end of the 17th century. the plague disappeared from Europe. The reasons for this are still unknown. It is assumed that with the change living conditions in Europe, the population began to live further from reservoirs of infection. Due to the lack of wood, houses began to be built from brick and stone, which are less suitable for rats than older wooden buildings.

Cholera. In the 19th century cholera pandemics occurred in most countries of the world. In the classic study of the London doctor J. Snow, the water route of transmission of infection during the cholera epidemic of 1853-1854 was correctly identified. He compared the number of cholera cases in two neighboring areas of the city that had different water supplies, one of which was contaminated with sewage. Thirty years later, the German microbiologist R. Koch, using microscopy and bacterial cultivation methods to identify the causative agent of cholera in Egypt and India, discovered the “cholera comma,” later called Vibrio cholerae.
Typhus. The disease is associated with unsanitary living conditions, usually during war. It is also known as camp, prison or ship fever. When in 1909 the French microbiologist C. Nicole showed that typhus is transmitted from person to person body lice, its connection with overcrowding and poverty became clear. Knowing how the infection is transmitted allows health workers to stop the spread of epidemic (lice) typhus by spraying insecticidal powder on the clothing and body of those at risk of infection.
Smallpox. Modern vaccination as a method of preventing infectious diseases was developed based on the early successes achieved by medicine in the fight against smallpox by immunizing (vaccinating) susceptible individuals. To administer the vaccine, fluid from a smallpox blister of a patient with an active infection was transferred to a scratch on the skin of the immunized person's shoulder or hand. If lucky, a mild illness occurred, leaving lifelong immunity after recovery. Sometimes immunization caused the development typical disease, but the number of such cases was so small that the risk of vaccination complications remained quite acceptable. In Europe, immunization began to be used in 1721, but long before that it was used in China and Persia. It was thanks to her that by 1770 smallpox ceased to occur in the wealthy sections of the population. The credit for further improvement of smallpox immunization belongs to the rural doctor from Gloucestershire (England) E. Jenner, who drew attention to the fact that people who had mild cowpox do not get smallpox, and suggested that cowpox creates immunity to human smallpox
(see also JENNER Edward). At the beginning of the 20th century. smallpox vaccine became readily available throughout the world due to its mass production and cold storage. The latest chapter in the history of smallpox was marked by a mass vaccination campaign carried out in all countries by the World Health Organization.
Yellow fever. In the 18th-19th centuries. Among the epidemic diseases of the Western Hemisphere, yellow fever occupied a prominent place in the United States, as well as in the countries of Central America and the Caribbean. Doctors, who assumed that the disease was transmitted from person to person, demanded the isolation of the sick to combat the epidemic. Those who linked the origin of the disease with atmospheric pollution insisted on sanitary measures. In the last quarter of the 19th century. yellow fever began to be associated with mosquito bites. In 1881, the Cuban doctor K. Finlay suggested that the disease was transmitted by Ades aegypti mosquitoes. Evidence of this was presented in 1900 by the yellow fever commission working in Havana, headed by W. Reed (USA). The implementation of the mosquito control program over the coming years contributed not only to a significant reduction in the incidence of disease in Havana, but also to the completion of construction of the Panama Canal, which was almost stopped due to yellow fever and malaria. In 1937, a doctor from the Republic of South Africa, M. Theiler, developed an effective vaccine against yellow fever, more than 28 million doses of which were produced by the Rockefeller Foundation from 1940 to 1947 for tropical countries.
Polio. Paralytic poliomyelitis (infantile paralysis) appeared as an epidemic disease at the turn of the 19th and 20th centuries. It is amazing that in underdeveloped countries with poor, unsanitary living conditions, the incidence of polio has remained low. At the same time, in highly developed countries, on the contrary, epidemics of this disease began to occur with increasing frequency and severity. The key to understanding the epidemic process of polio was the concept of asymptomatic carriage of the pathogen. This type hidden infection occurs when a person, having become infected with a virus, acquires immunity in the absence of any symptoms of the disease. Carriers, while remaining healthy themselves, can shed the virus, infecting others. It has been found that in conditions of poverty and crowded living conditions, the likelihood of contact with the virus increases sharply, as a result of which children become infected with polio very early, but the disease manifests itself quite rarely. The epidemic process proceeds as an endemic, secretly immunizing the population, so that only isolated cases of infantile paralysis occur. In countries with a high standard of living, such as North America and Northern Europe, there was a marked rise in the incidence of paralytic polio from the 1900s to the 1950s. The polio virus was isolated by K. Landsteiner and G. Popper already in 1909, but methods for preventing the disease were found only much later. Three serotypes (i.e., types present in the blood serum) of polioviruses have been identified, and strains of each of them were found in 1951 to be able to reproduce in tissue culture. Two years later, J. Salk reported his method of inactivating the virus, which made it possible to prepare an immunogenic and safe vaccine. The long-awaited inactivated Salk vaccine has become available for mass application since 1955. Polio epidemics in the United States have ceased. Since 1961, a live attenuated vaccine developed by A. Seibin began to be used for mass immunization against polio.
AIDS. In 1981, when acquired immunodeficiency syndrome (AIDS) was first described as a clinical form, its causative agent was not yet known. The new disease was initially recognized only as a syndrome, i.e. combination of characteristic pathological symptoms. Two years later, it was reported that the basis of the disease was the suppression of the body's immune system by a retrovirus, which was called the human immunodeficiency virus (HIV). Patients develop increased susceptibility to a variety of infectious pathogens, which manifests itself clinically only in the later stages of HIV infection, but initially the disease may remain in the incubation period for a very long time, up to 10 years.
(see also RETROVIRUSES). The first cases were homosexual men, then there were reports of transmission of the infection through transfusion of blood and its components. Subsequently, the spread of HIV infection was identified among injecting drug users and their sexual partners. In Africa and Asia, AIDS is transmitted primarily through sexual contact. Currently, the disease is spreading throughout the world, becoming an epidemic.
Ebola fever. Ebola virus as the causative agent of African hemorrhagic fever was first identified in 1976 during an epidemic in southern Sudan and the north of the Republic of Zaire. The disease is accompanied high temperature And heavy bleeding, mortality in Africa exceeds 50%. The virus is transmitted from person to person through direct contact with infected blood or other body secretions. Often infected medical staff, contribute to a lesser extent to the spread of infection household contacts. The reservoir of the infection is still unknown, but it may be monkeys, which is why strict quarantine measures have been introduced to prevent the import of infected animals.
EPIDEMIOLOGY
Epidemiology is scientific discipline, and profession, and research methodology. The epidemiological approach allows us to identify the causes and determine preventive measures for any disease, regardless of whether it is epidemic in nature or not. Analyzing variations in the frequency of this disease in different groups population, the factors that caused it can be discovered. Therefore, the focus of epidemiology is not on the medical histories of specific patients, but on the diseases themselves or other adverse events (for example, accidents or suicides) with the characteristics that are inherent in them in certain population groups. The population groups being studied should be characterized by parameters such as observation period and habitat, age and sex composition, as well as socio-economic status. Further, within a certain population group, subgroups are distinguished that differ in the degree of contact with potentially harmful factors. This may be a specific agent, such as a virus or radiation, or general influences associated with profession or dietary habits. Epidemiology usually finds practical application in activities public services health care, with a sufficient level of responsibility and authority for this. Epidemiological analysis and preventive measures are based on mortality and fertility statistics, as well as on morbidity statistics subject to mandatory registration, and on the results of special surveys.
See also VACCINATION AND IMMUNIZATION; articles about individual diseases.

Collier's Encyclopedia. - Open Society. 2000 .

See what "EPIDEMIC" is in other dictionaries:

- (Greek epi among, and demos people). A widespread, contagious disease. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. EPIDEMIC is any disease that simultaneously affects many people in the same area or in... ... Dictionary of foreign words of the Russian language

epidemic- and, f. Epidémie f., German. Epidemie lat. epidemia is a general disease. Wide distribution of which l. contagious disease; a rapidly spreading contagious disease. ALS 1. In Astrakhan, rotten and sultry, this epidemic will be stronger than we expect in others... ... Historical Dictionary of Gallicisms of the Russian Language

See sea... Dictionary of Russian synonyms and similar expressions. under. ed. N. Abramova, M.: Russian Dictionaries, 1999. panzootic epidemic, pandemic, pestilence, pestilence, pestilence, death, epidemic disease, pestilence Slo... Dictionary of synonyms

EPIDEMIC, epidemics, women. (Greek epidemia, lit. stay among the people). 1. A contagious disease that has spread widely. Typhoid epidemic. Cholera epidemic. 2. transfer used to denote something that has spread widely. Dictionary Ushakova... ... Ushakov's Explanatory Dictionary

Epidemic (Greek ἐπιδημία - general disease, from ἐπι - on, among and δῆμος - people) translated from Greek means “endemic disease among the people.” Since ancient times, this is the name given to diseases that progress in time and space and exceed the normal incidence rate in a given territory. But today we will talk about pandemics - epidemics that spread throughout an entire country, several countries, or even outside the country.

Plague

When it comes to epidemics, the first thing that comes to mind is the Black Death, a plague pandemic that wiped out a large part of the European population and swept through North Africa and the island of Greenland in 1346-1353. The first mention of this terrible disease dates back to 1200 BC. The event is also described in the Old Testament: the Israelites are plagued by failures in the war with the Philistines; after another battle, the Philistines capture the Ark of the Covenant and deliver it to the city of Azoth at the feet of the statue of their god Dagon. Soon a plague hits the city. The Ark was sent to another city, where the disease broke out again, and then to a third city, in which the kings of the five cities of Philistia decided to return the relic to its place, fearing new victims. The priests of Philisteia associated this disease with rodents.

The first recorded worldwide plague epidemic began during the reign of the Byzantine Emperor Justinian I and lasted for two centuries from 541 to 750. The plague came to Constantinople through Mediterranean trade channels and spread throughout Byzantium and neighboring countries. In 544, up to 5 thousand people died in the capital per day, sometimes the mortality rate reached 10 thousand people. In total, about 10 million people died; in Constantinople itself, 40% of the inhabitants died. The plague spared neither the common people nor the kings - with the level of development of medicine and hygiene, nothing depended on the availability of money and lifestyle.

The plague continued to repeatedly “raid” cities. This was facilitated by the development of trade. In 1090, merchants brought the plague to Kyiv, where they sold 7 thousand coffins over several winter months. In total, about 10 thousand people died. During the plague epidemic in 1096-1270, Egypt lost more than a million inhabitants.

The largest and most famous plague pandemic was the Black Death of 1346-1353. The sources of the epidemic were China and India; the disease reached Europe with Mongol troops and trade caravans. At least 60 million people died, and in some regions the plague wiped out between a third and half of the population. Later epidemics were repeated in 1361 and 1369. Genetic studies of the remains of disease victims showed that the epidemic was caused by the same plague bacillus yersinia pestis - before this, there were disputes about which disease caused numerous deaths during that period. Mortality rate bubonic form plague reaches 95%.

In addition to the economic factor, namely trade, an important role in the spread of the disease was played by the social one: wars, poverty and vagrancy, and the environmental one: droughts, rainstorms, and other weather misfortunes. Lack of food caused weakened immunity in people, and also served as a reason for the migration of rodents carrying fleas with bacteria. And, of course, hygiene in many countries was appalling (or simply non-existent), from the point of view modern man.

In the Middle Ages, renunciation of life's pleasures and conscious punishment of the sinful body were common in monastic circles. This practice included refusing to wash: “Those who are healthy in body, and especially those who are young in age, should wash as little as possible,” said Saint Benedict. Masses of emptied pots flowed like a river along the city streets. Rats were so common, and they interacted so closely with humans, that at that time there was a recipe in case a rat bit or wet someone. Another reason for the spread of the disease was the use of the dead as biological weapons: during a siege, fortresses were bombarded with corpses, which made it possible to destroy entire cities. In China and Europe, corpses were dumped into bodies of water to infect settlements.

The third plague pandemic originated in the Chinese province of Yunnan in 1855. It lasted for several decades - by 1959, the number of victims worldwide had dropped to 200 people, but the disease continued to be recorded. At the end of the 19th and beginning of the 20th centuries, outbreaks of plague occurred in the Russian Empire and the USSR, in the USA, India, South Africa, China, Japan, Ecuador, Venezuela and many other countries. In total, the disease claimed about 12 million lives during this period.

In 2015, scientists discovered traces of yersinia pestis in a flea from a 20-million-year-old piece of amber. The rod is similar to its descendants and is located in the same part of the flea as in modern distributors of the bacterium. Blood stains were found on the insect's proboscis and front limbs. That is, the plague spreader has supposedly existed for 20 million years, and has been transmitted in the same way for all this time.

Although we began to wash our hands more often and hugged infected rats less, the disease did not disappear. Every year, about 2.5 thousand people fall ill with the plague. Fortunately, the mortality rate has dropped from 95% to 7%. Individual cases are registered almost every year in Kazakhstan, Mongolia, China and Vietnam, Africa, the USA and Peru. In Russia, from 1979 to 2016, not a single plague disease was registered, although tens of thousands of people are at risk of infection in natural foci. The last case was registered on July 12, 2016 - ten year old boy was admitted to the infectious diseases department with a temperature of 40 degrees.

Smallpox

The mortality rate from smallpox is up to 40%, but recovered people lose their vision completely or partially, and scars from ulcers remain on the skin. The disease is caused by two types of viruses, Variola major and Variola minor, and the mortality rate of the latter is 1-3%. Viruses are transmitted from person to person without the participation of animals, as is the case with the plague. A disease that causes many ulcers on the body - pustules - has been known since the beginning of our era.

The first epidemics were observed in Asia: in the 4th century in China, in the 6th century in Korea. In 737, smallpox caused the death of 30% of the Japanese population. The first evidence of smallpox's presence in the West is found in the Qur'an. In the 6th century, smallpox spread to Byzantium, and after that, Muslim Arabs, who conquered new lands, spread the virus from Spain to India. In the 15th century in Europe, almost every person suffered from smallpox. The Germans had a saying: “Few escape smallpox and love.” In 1527, smallpox, which came to America, claimed millions of lives; it mowed down entire tribes of aborigines (there is a version according to which the conquistadors deliberately threw blankets infected with smallpox to the Indians).

Smallpox was compared to the plague. Although the mortality rate for the latter was much higher, smallpox was more common - it was constantly present in people’s lives, “filling cemeteries with the dead, tormenting constant fear all those who have not yet suffered from it.” At the beginning of the 19th century, 40 thousand people died annually in Prussia. Every eighth person who became ill in Europe died, and among children the chance of dying was one in three. Every year, until the 20th century, about one and a half million people died from smallpox.

Humanity began early to take care of methods of treating this terrible illness, other than dressing the patient in red clothes, praying for his health and covering him with protective amulets. The Persian scientist Az-Razi, who lived in the second half of the 9th - first half of the 10th century, noted immunity to recurrent illness and mentioned inoculation of mild human smallpox. The method consisted of inoculating a healthy person with pus from a ripened pustule of a smallpox patient.

The method came to Europe by 1718, brought by the wife of the British ambassador in Constantinople. After experiments on criminals and orphans, smallpox was inoculated into the family of the British king, and then into other people on a larger scale. Vaccination had a 2% mortality rate, while smallpox killed tens of times more people. But there was also a problem: the vaccine itself sometimes caused epidemics. It later turned out that forty years of variolation caused 25 thousand more deaths than smallpox during the same period before the use of this method.

At the end of the 16th century, scientists discovered that cowpox, which appears as pustules in cows and horses, protects humans from contracting smallpox. Cavalry were much less likely to suffer from smallpox than infantry. Milkmaids died much less often from the disease. The first public vaccination with cowpox took place in 1796, then the eight-year-old boy James Phipps received immunity, and after a month and a half he failed to be vaccinated with smallpox. Soldiers and sailors began to be vaccinated in 1800 mandatory, and in 1807 Bavaria became the first country where vaccination was compulsory for the entire population.

To inoculate, material from one person's pockmark was transferred to another person. Lymph was carried along with syphilis and other diseases. As a result, they decided to use calf pockmarks as the starting material. In the 20th century, the vaccine began to be dried to make it resistant to temperature. Before this, children had to be used, too: to deliver smallpox from Spain to North and South America for vaccination, at the beginning of the 19th century, 22 children were used. Two were vaccinated with smallpox, and after the pustules appeared, the next two were infected.

The disease did not spare the Russian Empire; it had been exterminating people since 1610 in Siberia, and Peter II died from it. The first vaccination in the country was given to Catherine II in 1768, who decided to set an example for her subjects. Below is the family coat of arms of the nobleman Alexander Markov-Ospenny, who received nobility because material for grafting was taken from his hand. In 1815, a special smallpox vaccination committee was formed, which oversaw the compilation of a list of children and the training of specialists.

In the RSFSR, a decree on compulsory vaccinations against smallpox was introduced in 1919. Thanks to this decision, the number of cases decreased significantly over time. If in 1919 186 thousand patients were registered, then in 1925 - 25 thousand, in 1935 - a little more than 3 thousand. By 1936, smallpox was completely eradicated in the USSR.

Outbreaks of the disease were recorded later. Moscow artist Alexander Kokorekin brought the disease from India in December 1959 and “gave it” along with gifts to his mistress and wife. The artist himself died. During the outbreak, 19 people became infected from it, and another 23 people from them. The outbreak ended in death for three. To avoid an epidemic, the KGB tracked all of Kokorekin’s contacts and found his mistress. The hospital was quarantined, after which the population of Moscow began to be vaccinated against smallpox.

In the 20th century, up to 500 million people died from smallpox in America, Asia and Europe. The last time a smallpox infection was reported was on October 26, 1977 in Somalia. The World Health Organization declared that the disease had been defeated in 1980.

At this point, both plague and smallpox have remained largely in test tubes. The incidence of the plague, which still threatens some regions, has dropped to 2.5 thousand people a year. Smallpox, transmitted from one person to another for thousands of years, was defeated more than thirty years ago. But the threat remains: due to the fact that vaccination against these diseases is extremely rare, they can easily be used as biological weapons, which people already did more than a thousand years ago.

Cholera

Cholera outbreaks occurred 7 times in less than 200 years, and typhus - during the First World War alone, 3.5 million people died from it in Russia and Poland.

Cholera is caused by motile bacteria - Vibrio cholerae, Vibrio cholerae. Vibrios reproduce in plankton in salty and fresh water. The mechanism of cholera infection is fecal-oral. The pathogen is excreted from the body through feces, urine or vomit, and enters the new body through the mouth - with dirty water or through unwashed hands. Mixing leads to epidemics waste water With drinking water and lack of disinfection.

The bacteria produce an exotoxin, which in the human body causes ions and water to leak out of the intestines, leading to diarrhea and dehydration. Some types of bacteria cause cholera, others cause cholera-like dysentery.

The disease leads to hypovolemic shock, a condition caused by a rapid decrease in blood volume due to loss of water, and to death.

Cholera has been known to mankind since the time of the “father of medicine” Hippocrates, who died between 377 and 356 BC. He described the disease long before the first pandemic, which began in 1816. All pandemics spread from the Ganges Valley. The spread was facilitated by heat, water pollution and mass gatherings of people near rivers.

The causative agent of cholera was isolated by Robert Koch in 1883. The founder of microbiology, during cholera outbreaks in Egypt and India, grew microbes on gelatin-coated glass plates from the feces of patients and the intestinal contents of the corpses of the dead, as well as from water. He was able to isolate microbes that looked like curved sticks, similar to a comma. Vibrios were called "Koch's comma".

Scientists have identified seven cholera pandemics:

First pandemic, 1816-1824
Second pandemic, 1829-1851
Third pandemic, 1852-1860
Fourth pandemic, 1863-1875
Fifth pandemic, 1881-1896
Sixth pandemic, 1899-1923
Seventh pandemic, 1961-1975

A possible cause of the first cholera epidemic was abnormal weather, which caused a mutation of Vibrio cholerae. In April 1815, the Tambora volcano erupted in what is now Indonesia, a magnitude 7 disaster that claimed the lives of ten thousand island residents. Up to 50,000 people then died from the consequences, including starvation.

One of the consequences of the eruption was the “year without summer.” In March 1816 it was winter in Europe, there was a lot of rain and hail in April and May, and there were frosts in America in June and July. Germany was tormented by storms, and snow fell every month in Switzerland. A mutation of Vibrio cholerae, perhaps coupled with famine due to cold weather, contributed to the spread of cholera in 1817 throughout Asia. From the Ganges the disease reached Astrakhan. More than 30,000 people died in Bangkok.

The pandemic was stopped by the same factor that started it: the abnormal cold of 1823-1824. In total, the first pandemic lasted eight years, from 1816 to 1824.

The calm was short-lived. Just five years later, in 1829, a second pandemic broke out on the banks of the Ganges. It lasted for 20 years - until 1851. Colonial trade, improved transport infrastructure, and the movement of armies helped the disease spread throughout the world. Cholera reached Europe, the USA and Japan. And, of course, she came to Russia. The peak in our country occurred in 1830-1831. Cholera riots swept across Russia. Peasants, workers and soldiers refused to tolerate quarantine and high food prices and therefore killed officers, merchants and doctors.

In Russia, during the second cholera epidemic, 466,457 people fell ill, of whom 197,069 died. The spread was facilitated by the return of the Russian army from Asia after the wars with the Persians and Turks.

The third pandemic dates back to the period from 1852 to 1860. This time, more than a million people died in Russia alone.

In 1854, 616 people died from cholera in London. There were many problems with sewerage and water supply in this city, and the epidemic led to the fact that they began to think about them. To late XVI centuries, Londoners took water from wells and the Thames, as well as for money from special tanks. Then, over the course of two hundred years, pumps were installed along the Thames, which began pumping water to several areas of the city. But in 1815, sewers were allowed to be drained into the same Thames. People washed, drank, and cooked food in water, which was then filled with their own waste - for seven whole years. The sewers, of which there were about 200,000 in London at the time, were not cleaned, leading to the “Great Stench” of 1858.

London physician John Snow discovered in 1854 that the disease was transmitted through contaminated water. Society did not pay much attention to this news. Snow had to prove her point to the authorities. First he persuaded the handle of the water stand on Broad Street, where the outbreak was at its center, to be removed. He then compiled a map of cholera cases, which showed the relationship between the locations of the disease and its sources. The largest number of deaths was recorded in the vicinity of this particular water intake. There was one exception: no one died in the monastery. The answer was simple - the monks drank exclusively beer own production. Five years later, a new sewer system scheme was adopted.

The seventh and last cholera pandemic began in 1961. It was caused by the more persistent Vibrio cholerae in the environment, called El Tor - after the name of the quarantine station where the mutated Vibrio was discovered in 1905.

By 1970, El Tor cholera had spread to 39 countries. By 1975 it was observed in 30 countries. At the moment, the danger of cholera being imported from some countries has not gone away.

Highest speed The spread of infection is shown by the fact that in 1977, a cholera outbreak in the Middle East spread to eleven neighboring countries, including Syria, Jordan, Lebanon and Iran, in just a month.

In 2016, cholera is not as bad as it was one hundred or two hundred years ago. Many more people have access to clean water, and sewage rarely goes into the same bodies of water that people drink from. Sewage treatment plants and water supply are on a completely different level, with several degrees of purification.

Although cholera outbreaks still occur in some countries. One of the most recent cases of a cholera epidemic began (and continues) in Haiti in 2010. In total, more than 800,000 people were infected. During peak periods, up to 200 people fell ill per day. The country is home to 9.8 million people, meaning cholera has affected almost 10% of the population. It is believed that the epidemic was started by Nepalese peacekeepers who brought cholera into one of the main rivers of the country.

In October 2016, it was reported that Aden, Yemen's second largest city, had two hundred cases of cholera, with nine deaths. The disease spread through drinking water. The problem is exacerbated by famine and war. According to the latest data, cholera is suspected in 4,116 people throughout Yemen.

Typhoid

Under the name “typhoid”, which translated from ancient Greek means “cloudness of consciousness”, several infectious diseases are hidden at once. They have one common denominator - they are accompanied by mental disorders against the background of fever and intoxication. Typhoid fever was identified as a separate disease in 1829, and relapsing fever in 1843. Before this, all such diseases had one name.

Typhus

In the United States, this fever is still common, with up to 650 cases of the disease reported annually. The spread is evidenced by the fact that between 1981 and 1996, the fever was found in every US state except Hawaii, Vermont, Maine and Alaska. Even today, when medicine is at a much higher level, the mortality rate is 5-8%. Before the invention of antibiotics, the death rate reached 30%.

In 1908, Nikolai Fedorovich Gamaleya proved that the bacteria that causes typhus are transmitted by lice. Most often - clothes, which is confirmed by outbreaks in the cold season, periods of “lice”. Gamaleya substantiated the importance of disinfestation in order to combat typhus.

Bacteria enter the body through combs or other damage to the skin.
After a louse has bitten a person, the disease may not occur. But as soon as a person begins to itch, he rubs the lice’s intestinal secretions, which contain rickettsiae. After 10-14 days, after the incubation period, chills, fever, headache. After a few days, a pink rash appears. Patients experience disorientation, speech impairment, and temperature up to 40 °C. Mortality during an epidemic can be up to 50%.

In 1942, Alexey Vasilyevich Pshenichnov, a Soviet scientist in the field of microbiology and epidemiology, made a huge contribution to the methodology for the prevention and treatment of typhus and developed a vaccine against it. The difficulty in creating a vaccine was that rickettsia cannot be cultivated using conventional methods - the bacteria need living animal or human cells. A Soviet scientist has developed an original method of infecting blood-sucking insects. Thanks to quick start In several institutes for the production of this vaccine during the Great Patriotic War, the USSR managed to avoid an epidemic.

The time of the first typhus epidemic was determined in 2006, when the remains of people found in a mass grave under the Acropolis of Athens were examined. The Plague of Thucydides killed more than a third of the population of Athens in one year in 430 BC. Modern molecular genetic methods have made it possible to detect the DNA of the causative agent of typhus.

Typhus sometimes struck armies more effectively than a living enemy. The second major epidemic of this disease dates back to 1505-1530. The Italian doctor Fracastor observed her with the French troops besieging Naples. At that time, high mortality and morbidity rates of up to 50% were noted.

IN Patriotic War In 1812, Napoleon lost a third of his troops to typhus. Kutuzov's army lost up to 50% of its soldiers from this disease. The next epidemic in Russia was in 1917-1921, this time about three million people died.

Currently, antibiotics of the tetracycline group and chloramphenicol are used to treat typhus. Two vaccines are used to prevent the disease: the Vi-polysaccharide vaccine and the Ty21a vaccine, developed in the 1970s.

Typhoid fever

Typhoid fever is characterized by fever, intoxication, skin rashes and lesions lymphatic system lower section small intestine. It is caused by the bacterium Salmonella typhi. Bacteria are transmitted through the nutritional, or fecal-oral, route. In 2000, 21.6 million people worldwide suffered from typhoid fever. The mortality rate was 1%. One of the effective ways to prevent typhoid fever is washing your hands and dishes. And also attentive attitude To drinking water.

Patients experience a rash - roseola, brachycardia and hypotension, constipation, an increase in the volume of the liver and spleen and, which is typical for all types of typhus, lethargy, delirium and hallucinations. Patients are hospitalized and given chloramphenicol and biseptol. In the most severe cases, ampicillin and gentamicin are used. In this case it is necessary drinking plenty of fluids, it is possible to add glucose-salt solutions. All patients take leukocyte production stimulators and angioprotectors.

Relapsing fever

After being bitten by a tick or louse, a carrier of the bacterium, a person begins the first attack, which is characterized by chills, followed by fever and headache with nausea. The patient's temperature rises, the skin dries out, and the pulse quickens. The liver and spleen enlarge, and jaundice may develop. Signs of heart damage, bronchitis and pneumonia are also noted.

The attack lasts from two to six days, and repeats after 4-8 days. If the disease after a louse bite is characterized by one or two attacks, then tick-borne relapsing fever causes four or more attacks, although they are milder in clinical manifestations. Complications after the disease - myocarditis, eye damage, spleen abscesses, heart attacks, pneumonia, temporary paralysis.

For treatment, antibiotics are used - penicillin, chloramphenicol, chlortetracycline, as well as arsenic drugs - novarsenol.

Death from relapsing fever is rare, except in central Africa. Like other types of typhus, the disease depends on socio-economic factors - in particular, nutrition. Epidemics among population groups lacking access to qualified medical care, can lead to a mortality rate of up to 80%.

During the First World War in Sudan, 100,000 people died from relapsing fever, that’s 10% of the country’s population.

Humanity was able to capture plague and smallpox in a test tube thanks to high level modern medicine, but even these diseases sometimes break through to people. And the threat of cholera and typhus exists even in developed countries, let alone developing ones, where another epidemic may break out at any moment.

Flu

A viral infectious disease called influenza, one strain of which in 1918-1919 alone killed more than 50 million people out of an infected third of the world's population, and tuberculosis, due to which 2 million people die every year even now.

Flu is a viral disease, and viruses are very good at mutating. In total, scientists have identified more than two thousand variants of the virus. Several different strains have been killing hundreds of thousands and even millions of people in the last hundred years alone. Every year, up to half a million people die from epidemics.

People of any age are susceptible to the flu, but it can be most dangerous for children and the elderly. Most often, the disease ends in death when the patient is over sixty-five years old. Epidemics begin mainly in the cold season, at temperatures from +5 to -5, when air humidity decreases, which creates favorable conditions for the virus to enter the human body through the respiratory tract.

After an incubation period that lasts up to three days, the disease begins. When during an illness you feel irritation in the nose, trachea or bronchi, this means that the virus has penetrated the cells of the ciliated epithelium and is now destroying them. The person coughs, sneezes and constantly blows his nose. The virus then enters the bloodstream and spreads throughout the body. The temperature rises, headaches and chills appear. After three to five days of illness, the patient recovers, but remains fatigued. In severe forms, the flu can lead to brain swelling and various complications, including the development of bacterial infections.

The largest pandemic of the “Spanish flu” during the First World War claimed the lives of more than fifty million people, according to some estimates - up to hundreds of millions. It was the H1N1 strain, and it spread throughout the world. The name “Spanish Flu” was obtained only due to the fact that the epidemic, which all countries participating in the war were silent about, was only talked about in neutral Spain.

The H1N1 virus was a mutated virus common in wild birds. It came from just two mutations in the hemagglutinin molecule, the surface protein of the influenza virus that allows the virus to attach to a host cell.

In 1918, in Spain, 39% of the country's population became infected with influenza, including people in their twenties and forties, who were least at risk of contracting the disease. People's faces turned blue and pneumonia developed. Patients coughed up blood, which they could choke on in the later stages. But most often the disease was asymptomatic. However, some people died the very next day after infection.

The virus has spread throughout the world. It claimed more lives in eighteen months than the First World War itself did in four years. There were ten million soldiers killed in the war, twelve million civilians, and about fifty-five million wounded. The Spanish Flu killed between fifty and one hundred million people, and more than five hundred million people were infected. The epidemic was not localized to any one territory, but raged everywhere - in the USA, Europe, the RSFSR, China, Australia. The spread was facilitated by troop movements and developed transport infrastructure.

But why list the countries where the virus killed people? It's better to say where he didn't do it. He did not reach the island of Marajo in Brazil. In other places he sometimes mowed down all the doctors. People were buried without funeral services or coffins, burying them in mass graves.

The percentage of deaths from the country's population (not from those infected) ranged from 0.1% in Uruguay and Argentina to 23% in Samoa. In the RSFSR, with a population of 88 million, 3 million people died. But today that same “Spanish flu” could not achieve the same result. Over the past hundred years, humanity has accumulated antibodies to various strains of the influenza virus - so not only viruses can mutate.

The Spanish flu became the official version of the cause of death of the famous Russian silent film actress, Vera Kholodnaya. In February 1919, she fell into the snow from an overturned sleigh, and the next day she developed a fever. A few days later, on February 16, 1919, Vera Kholodnaya died. The actress's sister recalled:

“There was a real epidemic in Odessa, and the disease was very difficult, and Vera’s was somehow especially difficult. Professors Korovitsky and Uskov said that the “Spanish flu” progressed like pneumonic plague in her... Everything was done to save her. How she wanted to live!”

The Asian flu caused the second influenza pandemic of the 20th century. The H2N2 virus was discovered in China People's Republic in 1956. The pandemic has reached Singapore and the USA. In the United States, the death toll reached sixty-six thousand people. The virus has killed up to four million people worldwide. The developed vaccine helped stop the spread of the disease by 1958.

The Asian flu virus has mutated. In 1968-1969 it caused an epidemic hong kong flu: H3N2. Then the disease claimed the lives of a million people.

"Some guy will wake you up
And he will let you into a world where in the past there are wars, stench and cancer,
Where the Hong Kong flu was defeated.
Are you happy with everything ready, fool?”
Vladimir Vysotsky. "The Ballad of Going to Heaven"

You probably remember the recent hysteria about bird flu. It was the H5N1 strain - the “successor” of two previous causes of influenza pandemics. From February 2003 to February 2008, 361 people became infected with the disease, and 227 of them died. And bird flu threatens Russia again. On November 23, 2016, it was reported that the first case of avian influenza was registered on farms in Kalmykia. The disease could have been carried by migratory birds. In the Netherlands, dead birds with confirmed influenza infection were discovered even earlier.

Another strain of influenza that can spread from animals to humans through a number of mutations is called swine flu. Outbreaks of this flu occurred in 1976, 1988, and 2007. The World Health Organization and the US Centers for Disease Control and Prevention expressed serious concern about this strain in 2009, when the disease caused high mortality in Mexico. On April 29, the pandemic threat level was raised from 4 to 5 points out of 6 possible. By August 2009, more than 250 thousand cases of infection and 2,627 deaths had been reported worldwide. The infection has spread throughout the world.

On June 11, 2009, WHO declared the first pandemic in forty years - the swine flu pandemic.

There is an opinion that it is useless to get flu vaccinations, since this disease has too many strains. That is why you need to be vaccinated not against everything at once, but against viruses that are potentially threatening at a given time. For example, if the relevant services have already detected swine flu and predict its spread throughout the country, then it makes sense to think about vaccination. But when we have H1N1 every year, then perhaps it’s worth preparing for it in advance, just in case?

Tuberculosis

Tuberculosis is a widespread disease in the world. To understand the scale: a third of the world's population is infected with it. Eight million people are infected with it every year. For two million of them, the disease will become fatal.

The causative agent of tuberculosis is Koch's bacillus. These are bacteria from the Mycobacterium tuberculosis complex group. The bacterium infects the lungs and sometimes affects other organs. It is transmitted very easily - through airborne droplets during a conversation, due to coughing or sneezing of an infected person. It occurs in an asymptomatic form, and then from a latent form it can become active. Patients cough, sometimes with blood, they develop fever, weakness, and lose weight.

At open form decays, or cavities, appear in the lungs. In the closed form, mycobacteria are not detected in the sputum, so patients are of little danger to others.

Tuberculosis was virtually incurable until the 20th century. At the same time, he was called “consumption” from the word “waste away,” although this disease was sometimes not tuberculosis. Consumption meant a number of diseases with a wide range of symptoms.

One of the victims of tuberculosis was Anton Pavlovich Chekhov, a doctor by profession. From the age of ten he felt “tightness in the sternum.” Since 1884 he had bleeding from his right lung. Researchers believe that his trip to Sakhalin played a big role in Chekhov’s death. The weakening of the body due to several thousand kilometers on horseback, in damp clothes and wet felt boots, caused an exacerbation of the disease. His wife recalled that on the night of July 1-2, 1904, at a resort in Germany, Anton Chekhov himself ordered for the first time to send for a doctor:

“For the first time in my life I asked to send for a doctor. Afterwards he ordered some champagne. Anton Pavlovich sat down and somehow significantly and loudly said to the doctor in German (he knew very little German): “Ich sterbe.” Then he repeated for the student or for me in Russian: “I’m dying.” Then he took the glass, turned his face to me, smiled his amazing smile, said: “I haven’t drunk champagne for a long time...”, calmly drank it all to the bottom, quietly lay down on his left side and soon fell silent forever.”

Now they have learned to identify and treat tuberculosis early stages, but the disease continues to kill people. In 2006, 300 thousand people were registered at dispensaries in Russia, and 35 thousand people died from the disease.

In 2015, the mortality rate was 11 people per 100 thousand of the country’s population, that is, about 16 thousand people died from tuberculosis during the year, not including the combination of HIV + tuberculosis. In just one year, 130 thousand infected people were registered. The results compared to 2006 are encouraging. Every year, mortality from tuberculosis decreases by 10%.

Even as doctors try to combat tuberculosis and reduce mortality and morbidity, an important problem remains: drug resistance of the Koch bacterium. Multidrug resistance is four times more common than ten years ago. That is, now every fifth patient simply does not respond to a whole range of powerful drugs. Among them are 40% of those people who have already been treated before.

The problem of tuberculosis is most acute today in China, India and Russia. The World Health Organization plans to defeat the epidemic by 2050. If in the case of plague, smallpox and influenza we talked about certain epidemics and pandemics that broke out in different places, spread throughout the world and died out, then tuberculosis is a disease that has been constantly with us for tens and hundreds of years.

Tuberculosis is closely related to the social status of the patient. It is common in prisons and among the homeless. But you shouldn’t think that this will protect you, a person who works, for example, in an office, from illness. I already wrote above that Koch’s bacillus is transmitted by airborne droplets: a homeless person’s sneeze on the subway can land a manager or programmer in a hospital bed, risking being left without a lung. Much depends on immunity, on the strength of the body to resist infection. The body is weakened by poor and ill-conceived nutrition, lack of vitamins, and constant stress.

Vaccination against tuberculosis is practiced in Russia in the first 3-7 days of a newborn’s life using BCG, a vaccine prepared from a strain of weakened live bovine tuberculosis bacilli. It is grown in an artificial environment and has virtually no virulence for humans. Revaccination is done after seven years.

In the case of tuberculosis mass hysteria not observed in the media. At the same time, the disease is widespread throughout the planet and causes a huge number of deaths. Perhaps by 2050, WHO will truly be able to boast of ending the decades-long epidemic. At the moment, only vaccination and strong immunity can save Koch from the bacillus.

If in the case of tuberculosis and influenza the percentage of deaths and the number of people infected has been decreasing over the years, then the mortality rate from malaria, according to scientists, will double in the next twenty years due to a decrease in susceptibility to drugs. The second terrible disease we are talking about today is leprosy. In medieval France, lepers were condemned to death, a funeral service was served over the living, they were thrown with a couple of shovels of earth into the cemetery, and after such a funeral they were taken to a special house - a leper colony.

Malaria

Malaria was first described around 2700 BC in the Chinese chronicle. But the first epidemic could have happened much earlier; from 8 to 15 thousand years ago, malaria could have caused a sharp decline in the number of people on Earth.

The patient's joints begin to ache, fever and chills, and convulsions appear. A person becomes a bait for mosquitoes - he begins to smell delicious to them. This is necessary for plasmodia to reach their beloved host again, since humans are only a means of distribution for them.

Children and people with HIV/AIDS are most at risk. The disease can be fatal for them.

Malaria seems so far away African disease. Malaria mosquitoes themselves live in almost all climatic zones. But to risk infection, you need a large number of these insects and their rapid reproduction. Previously, malaria was called “swamp fever” precisely because it is common in places where there is no low temperatures, there are swamps and there is a lot of rainfall. The risk of infection is highest in the equatorial and subequatorial zones. In Russia, such mosquitoes are found throughout the European part of the country.

Malaria in Russia and the USSR was widespread until the 1950s. In order to cope with this disease in the resort area, swamps in Sochi were drained and reservoirs were oiled: they were covered with a layer of oil to destroy mosquito larvae.

Largest quantity cases in the history of the USSR were recorded in 1934-1935 - then 9 million people became infected. In 1962, malaria was defeated in the USSR. Isolated cases of infection were possible after this. During the war in Afghanistan in 1986-1990, the USSR recorded an increase in the number of infected people - 1314 cases.

Malaria affects 97 countries. Although nearly half of the world's population - 3.2 billion people - were at risk of malaria in 2015, the majority of cases occurred in sub-Saharan Africa. This is where 88% of cases and 90% of deaths from malaria occur.

In 2015, 214 million people became infected with malaria, and 438,000 of them died. Bill Gates and British Chancellor of the Exchequer George Osborne in January 2016 promised to give $4.3 billion to fight the disease. This money is planned to be spent on studying the disease and finding cures.

American Indians hundreds of years ago used the bark of the cinchona tree as an antipyretic. The Spanish naturalist Bernabe Cobo brought it to Europe in 1632. After the wife of the Viceroy of Peru was cured of malaria, wonderful properties the medicines were recognized throughout the country, then the bark was transported to Spain and Italy, and it began to be used throughout Europe. It took almost two hundred years for quinine to be isolated directly from the bark, which was used in powder form. It is still used to treat the disease.

For decades (or even hundreds) people have been trying to create a vaccine against malaria. Unfortunately, vaccines still do not have a 100% guarantee against the disease. In July 2015, the Moskirix vaccine was approved in Europe, which was tested on 15 thousand children. The effectiveness of this vaccine is up to 40% when administered four times from 0 to 20 months. The use of the vaccine will begin in 2017.

In October 2015, the Nobel Prize in Medicine was awarded to Youyou Tu for her discoveries in the fight against malaria. The scientist extracted artemisinin, an extract from the herb Artemisia annua, the use of which significantly reduces mortality from malaria. Interestingly, she spied the recipe from the alchemist Ge Hong in the book “Prescriptions for Emergency Care” of 340 AD. He advised squeezing the juice of wormwood leaves into plenty of cold water. Yuyu Tuu achieved stable results precisely in the case of cold extraction.

In 2015, scientists at the University of California created genetically modified mosquitoes that could quickly introduce a malaria-blocking gene into a population of regular mosquitoes. In addition, after the gene is introduced, the eyes of mosquitoes begin to fluoresce, which increases the chance of their detection in the dark.

Leprosy

Leprosy, or Hansen's disease, is a chronic granulomatosis: it affects the human skin, peripheral nervous system, eyes, respiratory tract, testicles, hands and feet. The outdated name for this disease is leprosy; it was mentioned in the Bible, was known in Ancient India and was common in Medieval Europe. It is so widespread that at the beginning of the 13th century in Europe there were 19 thousand leper colonies, special houses for lepers.

In 503, a decree was issued in France obliging all leprosy patients to live in leper colonies. A person with such a diagnosis was taken to church in a coffin, a funeral service was held, carried in the same coffin to the cemetery and lowered into the grave there. Then they threw down several shovels of earth, saying the words “You are not alive, you are dead to all of us.” Then the person was taken to the leper colony. A person could go out for a walk, but only by wearing a gray cloak with a hood and a bell around his neck to warn others about the approach of the “dead man.”

The appearance of the word “infirmary” is associated with the disease. Lepers were accepted into the knighthood of the Order of St. Lazarus. And they also took care of other patients. The order was located on the island of Lazaretto in Italy.

Until the 16th century, there was a leprosy epidemic in Europe, but the number of patients, for a reason unknown to science, decreased. Scientists in 2013 restored the DNA of bacteria from the year 1300, removing it from the teeth of people who died at that time in leper colonies. It turned out that in seven hundred years the bacterium has hardly changed. This suggests that people have simply developed relative immunity to the disease.

In 1873, the Norwegian physician Gerhard Hansen isolated the first bacterium that causes leprosy, Mycobacterium leprae. Mycobacterium lepromatosis was isolated in 2008; these bacteria are common in Mexico and the Caribbean. Until recently, it was believed that only humans suffered from leprosy. But it turns out that armadillos and squirrels can transmit the disease to us. Moreover, squirrels themselves suffer from leprosy - they develop ulcers and growths on their heads and paws. Sick animals were discovered in the UK in 2016.

Incubation period The disease can last 5 years, and symptoms in a person may not appear until 20 years after infection. Doctors distinguish three types of disease: lepromatous, tuberculoid and borderline.

With lepromatous, bumps or nodes up to the size of a pea appear on the skin, which can merge into large formations. Then ulcers open on these tubercles, filled with a large number of bacteria that cause the disease. These ulcers eventually affect not only the skin, but also reach the joints and bones of a person, after which the limbs can be amputated.

The tuberculoid type is characterized by damage only to the skin and peripheral nervous system. The perception of temperature and touch are impaired.

An unidentifiable type of leprosy can progress to any of the previous types. It can cause damage to the nervous system and deformation of the feet and hands.

Leprosy is spread through droplets from the nose and mouth through frequent contact with untreated people. In other words, shouts of “unclean, unclean” and a bell around the neck of the sick were too powerful a means of prevention. Today it is known that leprosy is not transmitted by touching a person and does not always lead to death. Previously, it was incurable and actually led to inevitable disability. It's a matter of means and methods: bloodletting against leprosy is not the best best method treatment, as well as cleansing the stomach.

A person may not get sick at all even with too close contact with infected flesh. The Norwegian doctor Daniel Cornelius Danielsen experimented on himself: he injected the blood of a leprosy patient, rubbed the pus of patients into scratches on his skin, and injected pieces of a leprosy tubercle from the patient under his skin. But he never got sick. Now scientists have suggested that the disease also depends on the DNA of a particular person.

A breakthrough in treatment came in the 1940s with the development of the anti-leprosy drug dapsone. The drug has an antibacterial effect not only against Mycobacterium leprae, but also kills Mycobacterium tuberculosis.

The disease is closely related to social status. As of 2000, the World Health Organization named 91 countries with endemic leprosy. 70% of leprosy cases occur in India, Burma and Nepal. At risk are those people who have weakened immune systems, who drink contaminated water, eat little and live below the poverty line.

The number of patients has decreased over time, although this figure does not always decrease on a yearly basis. In 1999, 640 thousand new cases of infection were recorded worldwide, in 2000 - 738 thousand, and in 2001 - 775 thousand. But in 2015 they got sick several times fewer people- 211 thousand.

In Russia in 2007, there were 600 patients with leprosy, of whom only 35% were hospitalized, while the rest were on outpatient treatment and under observation. There were 16 leper colonies in the USSR, and four of them have survived in Russia. Patients can go to their relatives, but remain under observation. In the Tersky leper colony in Stavropol region some patients live about 70 years. And they no longer die from the disease itself, but from old age.

As the World Health Organization notes, over 20 years, more than 16 million patients with leprosy have been cured. This disease has been defeated almost all over the world. Fortunately, the causative bacteria has not changed much and is not resistant to drugs. The most important thing is to diagnose the disease as early as possible and begin its treatment. People with weak immune systems and poor living conditions are still at risk.

Introduction………………………………………………………………………………….3

1. Epidemics and infectious diseases. Infectious agents………..5

Anthrax

Tularemia

• Typhus

2. Major epidemics. Pandemic………………………………………………………7

3. Causes of epidemic foci…………………………….....9

4. Mechanisms and routes of transmission……………………………………...9

Airborne

Fecal-oral

Transmission

Contact and household

5. General precautions for epidemics and diseases…………12

Preventive measures

Help with infectious diseases

Conclusion………………………………………………………………………………... 16

References………………………………………………………......... 17

Introduction

Epidemic (Greek ἐπιδημία - general disease) - widespread spread of any infectious disease (plague, smallpox, typhoid, cholera, diphtheria, scarlet fever, measles, influenza).

Infectious diseases are widespread throughout the world and are caused by various microorganisms. “Contagious” diseases have been known since ancient times; information about them can be found in the oldest written monuments: in the Indian Vedas, works Ancient China and Ancient Egypt.

The study of infectious diseases developed along with advances in other areas scientific knowledge and was determined, like them, by the development of the socio-economic basis of society. The final solution to the question of the existence of living creatures invisible to the naked eye belongs to the Dutch naturalist Antonio Van Leeuwenhoek (1632 - 1723), who discovered a world of tiny creatures unknown to him. But even after this discovery, microbes were not yet finally recognized as causative agents of infectious diseases, although some researchers tried to establish their role. Thus, the Russian doctor D. S. Samoilovich (1744 - 1805) proved the contagiousness of the plague and disinfected the things of patients, and also tried to vaccinate against this disease. In 1782, he used a microscope to look for the causative agents of the plague.

The mid-19th century was characterized by rapid development of microbiology. The great French scientist Louis Pasteur (1822 - 1895) established the participation of microbes in fermentation and decay, that is, in processes that constantly occur in nature; he proved the impossibility of spontaneous generation of microbes, scientifically substantiated and introduced sterilization and pasteurization into practice. Pasteur is responsible for the discovery of the causative agents of chicken cholera, septicemia, osteomyelitis, etc. Pasteur developed a method for preparing vaccines by artificially weakening (attenuation) of virulent microbes for the prevention of infectious diseases - a method that is still used today. They were prepared with vaccines against anthrax and rabies.

In the further development of microbiology, enormous credit belongs to the German scientist Robert Koch: (1843 - 1910). The methods of bacteriological diagnostics he developed made it possible to discover the causative agents of many infectious diseases.

Finally, in 1892, viruses were discovered by the Russian scientist D.I. Ivanovsky (1864 - 1920).

Simultaneously with the development of medical microbiology, the clinical knowledge of doctors was improved. In 1829, Charles Louis described in detail the clinical picture of typhoid fever, distinguishing this disease from the group of “fevers” and “fever”, which previously included all diseases that occurred with a high temperature. In 1856 Typhus was isolated from the group of “fever diseases”, and in 1865 - relapsing fever. Great achievements in the field of studying infectious diseases belong to the outstanding Russian professors S.P. Botkin, A.A. Ostroumov, N.F. Filatov. S.P. Botkin established the infectious nature of the so-called catarrhal jaundice - a disease now known as Botkin's disease. He described the clinical features of typhoid fever. His student

prof. N. N. Vasiliev (1852 - 1891) identified “infectious jaundice” (icterohemorrhagic leptospirosis) as an independent disease. A wonderful pediatrician, Prof. N.F. Filatov was the first to study and describe glandular fever - infectious mononucleosis, a disease currently known as Filatov's disease.

Epidemiology also developed successfully. Thanks to I.I. Mechnikov (1845 - 1916) and many other researchers at the end of the last century created a coherent doctrine of immunity (immunity) in infectious diseases. Open I.I. Mechnikov in 1882 - 1883. the phenomenon of phagocytosis, which laid the foundation for the doctrine of immunity, opened up prospects in the prevention and treatment of infectious diseases. These discoveries made it possible to develop and apply serological tests (agglutination, precipitation, etc.) tests in the clinic for the laboratory diagnosis of infectious diseases. Much credit for the development of immunology and the theory of infection belongs to N.F. Gamaleya (1859 - 1949), who also discovered the phenomena of bacteriophagy.

Wide opportunities for the development of scientifically based methods of combating infectious diseases opened up in our country after the Great October Socialist Revolution. The fight against infectious diseases in the USSR became widespread. A network of anti-epidemic institutions was created, infectious diseases hospitals were opened, departments of infectious diseases were established in medical institutes, and special research institutes were created that studied infectious diseases, methods of their prevention and complete elimination.

The merit of Soviet scientists in studying issues of specific prevention of infectious diseases is enormous. Currently, highly effective live vaccines against brucellosis, smallpox, anthrax, tularemia, plague, leptospirosis and some other diseases are successfully used. In 1963, Soviet scientists A. A. Smorodintsev and M. P. Chumakov were awarded the Lenin Prize for developing a vaccine against polio.

Various chemicals have long been used to treat infectious diseases. Earlier than others, an infusion of quinine bark was used to treat malaria, and from 1821 - quinine. At the beginning of the 20th century, arsenic preparations (arsacetin, salvarsan, neosalvarsan, etc.) were released, which are still successfully used to treat syphilis and anthrax. In the 30s of our century, sulfonamide drugs (streptocide, sulfidine, etc.) were obtained, which marked a new period in the treatment of infectious patients. Finally, in 1941, the first antibiotic was obtained - penicillin, the importance of which is difficult to overestimate. For the production of penicillin, the work of domestic scientists V.A. was important. Manassein, A.G. Polotebnov, English microbiologist Alexander Flemming. Streptomycin was produced in 1944, chloromycetin in 1948, and chloromycetin in 1948 - 1952. - tetracycline drugs. Antibiotics are now the main treatment for most infectious diseases.

Along with successes in the field of prevention and treatment of many infectious diseases, there are currently significant achievements in the field of their clinical study. Only in recent years have several new infectious diseases, mainly of viral etiology, been discovered and studied. Much attention is paid to issues of pathogenesis, clinical features of the modern course of infectious diseases, in particular in vaccinated people; Treatment methods are being improved.

Research in the field of infectious pathology continues on a broad front.

Epidemics and infectious diseases

An epidemic is a massive spread of an infectious disease of people, progressing in time and space within a certain region, significantly exceeding the incidence rate usually recorded in a given territory. An epidemic, as an emergency, has a focus of infection and stay of people sick with an infectious disease, or a territory within which, within a certain time frame, it is possible to infect people and farm animals with pathogens of an infectious disease.

Based on social and biological factors epidemic lies epidemic process, that is, the continuous process of transmission of the infectious agent and a continuous chain of successively developing and interconnected infectious conditions (disease, bacterial carriage).

Sometimes the spread of the disease has the nature of a pandemic, that is, it covers the territories of several countries or continents under certain natural or social and hygienic conditions. A relatively high incidence rate can be recorded in a certain area for a long period. The occurrence and course of the epidemic is influenced both by processes occurring in natural conditions, and mainly by social factors(municipal improvement, living conditions, health care, etc.).

Infectious diseases in humans are diseases caused by pathogens and transmitted from an infected person or animal to a healthy one. Every year, more than 1 billion people on Earth suffer from infectious diseases.

The causative agent of the disease invades certain organs, multiplies and poisons the body with the products of its vital activity. The ability of some microorganisms to cause diseases is called their pathogenicity.

The transmission of pathogens from sick to healthy people occurs through the environment in various ways. For example, pathogens of intestinal infections are transmitted through water, food, and are carried by flies and wasps. The most dangerous pathogens are those transmitted through the air with droplets of saliva released when talking, coughing, sneezing (for example, influenza, measles, chickenpox, diphtheria, etc.), since they most often lead to epidemics.

The most dangerous diseases, taking the form of an epidemic:

Plague - acute natural focal infectious disease caused by a bacillus

plague - Yersinia pestis. Refers to particularly dangerous infections. There are a number of natural foci around the globe where plague is constantly found in a small percentage of the rodents living there. Epidemics of plague among people were often caused by the migration of rats infected in natural foci. From rodents to humans, microbes are transmitted through fleas, which, in the event of mass death of animals, change their host. In addition, a possible route of infection is when hunters process the skins of killed infected animals. Fundamentally different is infection from person to person, carried out by airborne droplets. Sporadic cases of plague have been reported in different countries, including in the USA.

Plague agent It is also stable at low temperatures, preserves well in sputum, but at a temperature of 55 ° C it dies within 10-15 minutes, and when boiled - almost immediately. Enters the body through the skin (from a flea bite), mucous membranes of the respiratory tract, digestive tract, and conjunctiva.

When a person is bitten by fleas infected with plague bacteria, a papule or pustule filled with hemorrhagic contents (cutaneous form) may appear at the site of the bite. Then the process spreads through the lymphatic vessels without the appearance of lymphangitis. The proliferation of bacteria in macrophages of the lymph nodes leads to their sharp increase, merger and formation of a conglomerate (bubonic form). Further generalization of the infection, which is not strictly necessary, especially in the conditions of modern antibacterial therapy, can lead to the development of a septic form, accompanied by damage to almost all internal organs. However, from an epidemiological point of view, the most important role is played by the “screening out” of infection into the lung tissue with the development of the pulmonary form of the disease. From the moment plague pneumonia develops, the sick person himself becomes a source of infection, but at the same time, the pulmonary form of the disease is already transmitted from person to person - extremely dangerous, with a very rapid course.

Anthrax- an acute infectious disease from the group of zoonoses. In humans it occurs in the form of cutaneous, pulmonary, intestinal and septic forms.

Pathogen- relatively large anthrax bacillus; forms spores and capsule. The vegetative form of the pathogen dies without access to air, when heated, or exposed to disinfectants. The spores of the pathogen are very stable in the external environment.

Tularemia - an acute infectious disease characterized by fever, general intoxication, damage to the lymphatic system, skin, mucous membranes, and in case of aerogenic infection, the lungs: it is classified as a zoonotic disease with natural focality. Distributed in many regions of Russia, the source of infection is many rodents.

Pathogen are small coccus-like rods, gram-negative, stable in the external environment. Tularemia is characterized by a variety of infection gates. The following routes of infection are distinguished: through the skin (contact with infected rodents, vector-borne transmission by blood-sucking insects), through the mucous membranes of the digestive organs (consumption of infected water and food) and the respiratory tract (inhalation of infected dust). The clinical forms of the disease are closely related to the portal of infection. With contact and transmissible infection, bubonic and cutaneous-bubonic forms of the disease develop, with aspiration - pneumonic, with alimentary - intestinal and anginal-bubonic forms of tularemia. When infected through the conjunctiva, the oculobubonic form occurs. After an illness, immunity develops.

Cholera- acute infectious disease. It is characterized by the development of watery diarrhea and vomiting, disturbances of water and electrolyte metabolism, the development of hypovolemic shock, and impaired renal function. Refers to particularly dangerous infections.

Pathogen- Vibrio cholera of two varieties. The effect of Vibrio cholerae exotoxin on the epithelium of the mucous membrane of the small intestine is due to the loss of body fluid. There are no morphological changes in the epithelial cells and underlying tissues of the intestinal wall.

Typhus - acute rickettsial disease, characterized by fever, general intoxication, damage to blood vessels and the nervous system. Relapses of the disease are possible after many years (Brill's disease). Refers to transmissible anthroponoses, transmitted by lice.

Pathogen- Provacek's rickettsia; penetrate the body through the smallest damage to the skin during scratching, accompanied by rubbing infected lice excrement into the skin; multiply in the vascular endothelium, causing vasculitis, leading to circulatory disorders. The most pronounced changes are observed in the brain, adrenal glands, and skin. When the rickettsia breaks down, endotoxin is released, causing general intoxication.

Major epidemics

Pandemic (Greek πανδημία - the whole people) is an epidemic characterized by the emergence of a new virus or infectious disease against which the human population has no immunity, and leading to several simultaneous epidemics around the world with a huge number of diseases and deaths (for example, cholera, influenza) .

Known pandemics

Peloponnesian War (430 BC) - Typhus killed a quarter of the Athenian army and a quarter of the population within 4 years. The disease fatally weakened Athens' dominance, but the disease's lethality prevented it from spreading widely, meaning the disease killed the infected faster than he could transmit the disease. The exact cause of the epidemic was not known until 2006, when analysis of teeth found in excavations of a mass grave under the Acropolis of Athens revealed the presence of typhoid bacteria.

Plague

Justinian's plague (541-700) - brought to Byzantium from Egypt.

The Black Death is a pandemic of bubonic plague, brought from Eastern China, which passed through Europe in the mid-14th century (1347-1351). Up to 34 million people died (a third of Europe's population).

HIV- According to the Joint United Nations Program on HIV/AIDS (UNAIDS) and the World Health Organization (WHO), from 1981 to 2006, 25 million people died from diseases associated with HIV infection and AIDS. By the beginning of 2007, about 40 million people worldwide (0.66% of the world's population) were carriers of HIV.

Flu

Spanish flu (strain H1N1) - in 1918-1919, the disease claimed the lives of 40-50 million people.

Asian flu (H2N2 strain) - about 70 thousand people died in 1957-1958.

Hong Kong flu (H3N2 strain) - about 34 thousand people died in 1968-1969.

Bird flu (strain H5N1) - killed about 360 people between 2003 and 2008.

Swine flu (H1N1 strain) - killed about 1,900 people in 2009-2010.

Traces of some diseases are found in ancient burials. For example, traces of tuberculosis and leprosy were found on Egyptian mummies (2-3 thousand years BC). Symptoms of many diseases are described in the most ancient manuscripts of the civilizations of Egypt, India, Sumer, etc. Thus, the first mention of the plague is found in an ancient Egyptian manuscript and dates back to the 4th century BC.

The causes of epidemics are limited. For example, a dependence of the spread of cholera on solar activity was discovered; out of six of its pandemics, four are associated with the peak of active sun. Epidemics also occur during natural disasters that cause the death of a large number of people, in countries affected by famine, and during major droughts that spread over large areas.

If a focus of infectious infection occurs in the affected area, it is introduced quarantine or observation. Permanent quarantine measures are also carried out by customs at state borders.

Quarantine is a system of anti-epidemic and security measures aimed at completely isolating the source of infection from the surrounding population and eliminating infectious diseases in it. Armed guards are installed around the outbreak; entry and exit, as well as the removal of property, are prohibited. Supplies are made through special points under strict medical supervision.

Observation is a system of isolation and restrictive measures aimed at limiting the entry, exit and communication of people in a territory declared dangerous, strengthening medical surveillance, preventing the spread and eliminating infectious diseases. Observation is introduced when pathogens that are not classified as particularly dangerous are identified, as well as in areas directly adjacent to the border of the quarantine zone.

More medicine Ancient World such methods of combating epidemics were known as removing sick people from the city, burning things of the sick and dead (for example, in Assyria, Babylon), involving those who had recovered from caring for the sick (in Ancient Greece), prohibiting visiting the sick and performing rituals with them (in Rus'). Only in the thirteenth century did quarantine begin to be used in Europe. To isolate lepers, 19 thousand leper colonies were created. The sick were forbidden to visit churches, bakeries, or use wells. This helped limit the spread of leprosy throughout Europe.

At the moment, quarantine and observation are the most reliable ways to combat epidemics.

Typically, the duration of quarantine and observation is set based on the duration of the maximum incubation period of the disease. It is calculated from the moment of hospitalization of the last patient and the end of disinfection.

The main causes of epidemic outbreaks.

An epidemic occurs when a pathogen spreads through a susceptible population. The intensity of the epidemic process is influenced by many environmental factors. Susceptibility to infection is characteristic of those populations that have not acquired immunity through previous contacts with the causative agent of this disease. Immunity occurs not only as a consequence of a previous illness, but also after vaccination with drugs containing antigens of a specific pathogen. Occasionally there are examples that infection with one pathogen can protect against infection caused by another; Thus, infection with the cowpox virus protects against smallpox.

Depending on how the infection spreads, susceptible populations can be protected by excluding their contact 1) with already sick individuals;

2) with pathogen vectors, such as mosquitoes, fleas or lice; 3) with objects that transmit infection, for example water, which may be contaminated with a pathogen; 4) with animals that serve as a reservoir of infection, such as rats.

Mechanisms and routes of transmission of infection

Each infectious disease has its own route of transmission of microorganisms, which was formed in the process of evolution and is the main way of preserving the pathogen as a species.

There are three phases of transition of a pathogen from one organism to another:

1) release of a microbial agent from the body into the environment;

2) presence of the pathogen in the environment;

3) penetration of infection into a completely new organism.

The mechanism of transmission of infectious agents occurs through these three phases, but may have its own characteristics depending on the primary localization of the pathogen. For example, when a pathogen is found in the cells of the mucous membrane of the upper respiratory tract, it is released with exhaled air, which contains microbial agents in aerosols (influenza, ARVI, chicken pox, whooping cough, scarlet fever). When the infection is localized in the cells of the gastrointestinal tract, it can be released through feces and vomit (dysentery, cholera, salmonellosis).

When the pathogen is in the bloodstream, the mechanism of its transmission will be blood-sucking insects (rickettsiosis, plague, tularemia, encephalitis). Contact mechanism - due to the localization of microbes on the skin.

Depending on the primary location of the pathogen in the human body, four mechanisms of transmission of infection are distinguished:

1) airborne;

2) fecal-oral (food);

3) transmission;

4) contact-household.

Airborne (dust, inhalation)– one of the most common and fastest ways of transmitting infectious diseases. Diseases caused by both viruses and bacteria can be transmitted this way. The accompanying inflammatory process of the mucous membranes of the upper respiratory tract contributes to the spread of pathogens. A large number of microbes are released with droplets of mucus when coughing, sneezing, talking, crying, screaming. The power of this transmission path depends on the characteristics (particle size being the most important) of the aerosols. Large aerosols disperse over a distance of 2–3 m and quickly settle, while small aerosols cover a distance of no more than 1 m when exhaling, but can long time remain suspended and move considerable distances thanks to electric charge and Brownian motion. Human infection occurs as a result of inhalation of air containing droplets of mucus, which contain the pathogen. With this method of transmission, the maximum concentration of pathogens will be near the source of infection (patient or bacteria carrier). As you move away from the source of infection, the concentration of microbes decreases significantly, but sometimes this is enough for the development of the disease, especially if the child is weakened and the pathogen has a high degree of pathogenicity. Cases have been described in which the transmission of influenza, measles, and chickenpox viruses occurred over considerable distances, through ventilation, stairwells, and corridors. The airborne transmission route depends on the stability of pathogens in the external environment. A large number of microorganisms quickly die when aerosols are added (influenza viruses, chicken pox, measles), while others are quite persistent and retain their vital activity and properties for a long time in the dust (up to several days). Therefore, a child can become infected when cleaning a room, playing with dusty toys, etc.; this “dust” transmission mechanism is effective for diphtheria, salmonellosis, tuberculosis, scarlet fever, escherichiosis and other diseases.

Fecal-oral (food) The transmission route is realized during the transmission of intestinal infections caused by both viruses and bacteria. Transmission factors include food, dirty hands, contaminated water, flies, and various household items. Thus, it is possible to develop dysentery, salmonellosis, staphylococcal enterocolitis and intestinal infections caused by opportunistic microorganisms (which cause diseases under unfavorable conditions) - Proteus, Klebsiella, Pseudomonas aeruginosa. Poliomyelitis, brucellosis, foot-and-mouth disease, scarlet fever, diphtheria, yersiniosis, hepatitis A, etc. are transmitted less frequently through the fecal-oral route. Diseases can develop when humans consume meat and milk from sick animals that have not been subjected to good heat treatment (salmonellosis, foot-and-mouth disease, anthrax , tularemia), but most often people become infected by consuming food products, in which the pathogen is located. Contamination of products is observed at different stages of their processing, preparation and further sale, which is often associated with violations of the technological process and sanitary standards: through the hands of food industry workers, dishes, equipment, through contact with the contents of the gastrointestinal tract of slaughtered animals - carriers of infection, through rodents, etc.

One of the main themes of 2014 was the extremely dangerous fever Ebola. Despite the rapid spread of the disease around the world, by the end of the year the panic subsided, and some countries declared that they had coped with the epidemic. Humanity has already been tested for strength by various viruses and bacteria more than a dozen times, and we have successfully dealt with even their most terrible representatives. About the bloodiest wars against infections and victories over them - in our digest.

Plague

The name of this disease has become a household word for all infections that have led to pandemics. The causative agent of the disease is the plague bacillus, and its transmission to humans occurs from fleas or rodents.

People first started talking about the plague in 540 AD, and over the next hundred years, throughout to the globe The epidemic killed more than 150 million people. To understand the global scale of the disaster, it is worth knowing that the entire population of the world at that time did not exceed 400-450 million. The first meeting of mankind with this disease went down in history as the “Justinian Plague”, named after the ruling Byzantine Emperor Justinian I at that time.

It was Soviet scientists who managed to bring the disease to its knees. In 1947, during an outbreak of plague in Manchuria, they used streptomycin for the first time in the world. Thanks to them, even the most hopeless patients recovered. Yes, isolated outbreaks of plague still occur, but experts have established that correct treatment plague treatment should be carried out using antibiotics, sulfonamides and medicinal anti-plague serum. Then mortality from infection occurs only in 5-10 percent of cases.

For the second time, the plague, which received the sonorous name “Black Death,” appeared in the 14th century. As befits a real pandemic, it raged almost simultaneously across Africa and Eurasia. At the same time, the disease received another name - “bubonic plague”; buboes are abscesses and tumors that appeared in the sick. The place where “patient zero” appeared was the Gobi Desert, and from here, together with the hordes of the Golden Horde, the disease spread throughout the globe within 10 years. As the first time, the consequences of the infection were terrible: Europe was devastated, having lost, according to some estimates, up to 40 percent of the population, several hundred cities and villages died out in China and India, the number of dead in Africa cannot be counted at all.

The third acquaintance of a person with the plague bacillus occurred in 1855 in China. The mountain valleys of Yunnan suffered alone from the infection for four decades, but by the beginning of the 20th century, thanks to traders and armies, the infection had spread to the rest of the world. In general, the third “wave” was not so destructive, although it noticeably battered China and India, killing about 20 million people in total.

Cholera

Cholera as deadly intestinal infection has been known to mankind since ancient times. It is mentioned by Hippocrates and Celsus. The disease is characterized by rapid loss of body fluids, dehydration and subsequent death. But until the 19th century, the disease never behaved aggressively and was always limited to isolated outbreaks at the sites of earthquakes and floods.

In 1816, the first cholera pandemic began in what is now Bangladesh. Its victims were thousands of British soldiers, millions of Indians and more than a hundred thousand people on the island of Java. By the middle of the century, the disease reached Russia; this moment is described in history thanks to numerous “cholera riots.” Then the infection spread to Germany, France, and Great Britain, leaving behind up to 60 thousand corpses in each country. Cholera then moved overseas and killed more than 250 thousand people in the United States and Canada.

By 1860, the infection, which had almost disappeared, reappeared. In Russia, a million people die from it, almost one and a half million die throughout Europe. Cholera would kill another 10 million people before 1923. The last time a cholera pandemic was declared was in 1962, although isolated cases and focal outbreaks of the disease are still recorded.

Treatment of cholera consists of combating dehydration and loss of vital energy from the body. important elements, as well as in the use of the simplest antibiotics, to which the virus has not developed resistance.

Smallpox

Smallpox, like cholera, has been known to doctors since ancient times. It is a highly contagious infection with a mortality rate of more than 40 percent. And if you do manage to survive, you will most likely go blind and be covered in scars from ulcers for life.

According to chronicles, the first smallpox epidemics were recorded in Asia from the 4th to the 8th centuries AD. Lack of knowledge about the disease led to disastrous consequences: the population of China and Korea decreased by a quarter, Japan by 40 percent. In the 17th-18th centuries, mortality from smallpox in Europe and Russia amounted to up to 1.5 million people per year. The number of those who recovered but remained disabled reached 20 million.

It was at this time that doctors and scientists from several countries began to pay attention to a strange pattern: people who are in direct contact with animals - shepherds, milkmaids, cavalrymen, suffer from natural or “black” smallpox much less often than others. It was later discovered that infection with cowpox makes a person almost completely immune to the natural disease. Mass vaccinations began, but the positive effect weakened over time; revaccination was required, which people often ignored, believing that they had exposed themselves to an unnecessary risk the first time. As a result, by 1875, about a million people were dying annually in Europe.

In 1928, due to widespread vaccinations, smallpox ceased to threaten humanity. However, before that, in the 20th century, it managed to destroy up to 400 million people. It was Soviet scientists who in 1958 offered the world 25 million smallpox vaccine to fight the disease. So far, smallpox is considered eradicated, and the only two copies of this virus are stored in the Russian state scientific center virology and biotechnology "Vector" and in American Center for disease control and prevention.

Interestingly, smallpox is most likely the most dangerous disease for kings and emperors. IN different times Queen Mary II of England, the leader of the Aztecs Cuitlauac, King Louis XV of France and three Japanese emperors died from it.

Spanish flu or "Spanish flu"

The most widespread and deadly influenza pandemic in human history. The flu acquired its name from the place where it first appeared - Spain, where by May 1918 about 9 million people were already sick with it. The First World War and the associated movements of millions of armies contributed to the almost immediate spread of the virus throughout the earth: from Alaska and Greenland to Australia and the Amazon jungle. Technological progress, so praised by scientists of that time, also did its job: trains, ships and airships replicated the virus so quickly that in the first 30 weeks of its existence, the virus killed more than 35 million people worldwide. In total, about 600 million, or almost a third of the world's population, suffered from the Spanish flu, and according to various sources, from 60 to 100 million people died.

About 3 million people died in Russia, including such prominent people as silent film legend Vera Kholodnaya, revolutionary Yakov Sverdlov, and engineer Leonid Kapitsa. Around the world, the following were the victims of influenza: famous personalities, like the poet Guillaume Apollinaire, philosopher and sociologist Max Weber. Cases of death on the streets in major cities of the world were so common that passers-by did not even turn around, and the number of mourning and funeral processions resembled a terrible and frightening parade. There is a well-known story about one undertaker from New York who earned 150 thousand dollars in one month! True, he did not have time to use this amount - he died of the flu.

In 2009, the Spanish flu reappeared, albeit more mild form. The H1N1 strain, known in the early twentieth century as the “Spanish flu,” has now changed its name to “swine flu” and is treated like other types of flu.