Latest epidemics. History of world epidemics

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 more than a dozen times various viruses We have successfully dealt with both bacteria and 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.

The plague was first discussed in 540 AD, and over the next hundred years the epidemic killed more than 150 million people around the globe. 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 arose in sick people. The place where the “zero patient” 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. Like 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. Last time The cholera pandemic was declared 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 have begun, but 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 no longer threatens 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 the American Center for Disease Control and Prevention.

Interestingly, smallpox is most likely the most dangerous disease for kings and emperors. IN different time Queen Mary II of England, the Aztec leader 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 got its name from the place where it first appeared - Spain, where by May 1918 about 9 million people were already sick with it. First World War and the associated movements of millions of armies contributed to the almost instantaneous 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. Deaths on the streets in major cities the world were so ordinary 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 at the beginning of the twentieth century as the “Spanish flu,” has now changed its name to “ swine flu", and is treated like other types of flu.

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 doctrine of infectious diseases developed along with advances in other areas of 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 was 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 prepared 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 infectious nature so-called catarrhal jaundice - a disease now known as Botkin's disease. He described clinical features typhoid fever. His student

prof. N. N. Vasiliev (1852 - 1891) highlighted in independent illness“infectious jaundice” (icterohemorrhagic leptospirosis). 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 laboratory diagnostics 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.

Ample opportunities for the development of scientifically based methods of combating infectious diseases opened 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 the 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 during recent years Several new infectious diseases, mainly of viral etiology, have 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 An epidemic is an epidemic process, that is, a continuous process of transmission of an infectious agent and an unbroken chain of sequentially 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 by both the processes occurring in natural conditions, and mainly 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:

Disease	Distribution method	Latent period, day	Duration of loss of performance, days	Mortality without treatment, %
Plague	Spraying in the air; contamination of water, food, household items; artificial infection of vectors.		7 – 14 (with bubonic form)	100 (for pulmonary and septic forms)
anthrax	Spraying spores in the air, artificially infecting vectors			Up to 100 (with pulmonary intestinal form)
Tularemia	Spraying spores into the air
Cholera
	Penetrate into the body through tiny breaks in the skin

Plague - acute natural focal infectious disease caused by a bacillus

plague - Yersinia pestis. Refers to particularly dangerous infections. There is a series of natural foci, where plague consistently occurs 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. The process then spreads across lymphatic vessels without manifestation of lymphangitis. Reproduction of bacteria in macrophages lymph nodes leads to their sharp increase, fusion 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 “screening out” of infection in 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, resistant to 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 small intestine caused by loss of body fluid. There are no morphological changes in the epithelial cells and underlying tissues of the intestinal wall.

Typhus - an 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 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 middle of the 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 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.

On this 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 factors environment. Susceptibility to infection is characteristic of those populations that have not acquired immunity through previous contacts 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; yes, virus infection cowpox 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, chickenpox occurred over considerable distances, through ventilation, staircases, and corridors. The airborne route of transmission 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, utensils, equipment, through contact with the contents of the gastrointestinal tract of slaughtered animals - carriers of infection, through rodents, etc.

The most terrible epidemics and pandemics in human history

The Renaissance, with its balls and wonderful romantic relationships, paints us a utopian picture of a healthy, prosperous society, and the era of revolutions speaks of the genius of an advanced mind. But we forget that in those days communications were not developed like today, there was no sewage system as such, instead of the usual taps there were only wells with stagnant water, and the lush hairstyles of ladies were infested with lice, but this is only the most harmless phenomenon past years. Due to the lack of refrigerators, people had to store food in a room where rats, carriers of deadly diseases, scurried about in hordes, and malaria-carrying mosquitoes swarmed near wells. Damp, poorly heated rooms became the cause of tuberculosis, and unsanitary conditions and dirt is the source of cholera.

Perhaps the word “plague” is in the everyday life of every nation, and everywhere it brings horror. It’s not for nothing that there is even such a proverb: to be afraid of the plague, that is, to be afraid of something in a panic. After all, it’s true that literally 200-400 years ago another epidemic of the disease claimed millions of lives due to the lack of the necessary antibiotic in the doctors’ arsenal. What can I say, to this day there is no antidote for many diseases - you can only delay, but not stop, the death of the human body. It would seem progressive modern medicine should protect humanity from various epidemics, but viruses also adapt to new conditions, mutate, becoming a source of danger to life and health.

Black Death. The plague became the world's first global epidemic, which in 1348 killed almost half of the world's population. The disease arose in poor neighborhoods with a concentration of rats and entered the homes of the bourgeoisie. In just two years, the plague killed 50 million people, more than the world wars. It literally devastated entire cities; there was not a single family that was not affected by this infection. People fled from the plague, but there was no escape from it anywhere; instead, the black death captured more and more new states on its way. The disaster was pacified only 3 years later, but its individual, weaker manifestations shook European cities until the end of the 19th century. Poor doctors had to risk their lives to examine patients. In order to somehow protect themselves from infection, they wore uniforms made of coarse fabric, impregnated with wax, and on their faces they put masks with long beaks, where aromatic substances were placed. foul odor, which helped avoid infection.

Black Smallpox. Just think, at the beginning of the 16th century, America was inhabited by 100 million people, but terrible epidemics in just a few centuries reduced the number by 10-20 times, leaving 5-10 million survivors on the continent. The indigenous population lived quite happily until New World the countless stream of European migrants did not pour in, bringing with them death in the form of smallpox. Again black and again an epidemic. If the plague killed 50 million people, then smallpox killed 500 million. Only at the end of the 18th century was a vaccine found against the epidemic disease, but it could not save people from the outbreak in 1967, when over 2 million people died. The disease was so imminent that the Germans couched it in the saying “Love and smallpox escape only a few.” The royals also failed to avoid a sad fate. It is known that the English Queen Mary the Second, Louis the First of Spain and Peter the Second died of smallpox. Mozart, Stalin, Glinka and Gorky managed to survive smallpox. Catherine the Second was the first to ensure that her subjects were vaccinated against the disease.

Spaniard. This name was given to the flu that raged at the beginning of the 20th century. Before people had time to recover from the horrors of the First World War, a new attack struck them. The Spanish flu claimed 20 million lives in just a couple of months, and over the entire period of the epidemic, according to various sources, from 50 to 100 million people. During the course of the illness, the person’s appearance changed so much that he looked like a guest from another world. It is this virus that is associated with the spread of rumors about vampires. The fact is that the rare lucky one who managed to overcome the disease was white as a sheet with black spots on his cheeks, cold limbs and red eyes. People took them for Walking Dead, that's why they spread rumors about vampires. Perhaps the Spanish flu became the worst epidemic in human history.

Malaria. Probably the oldest pandemic, which in different periods covered various countries. Because of the blood-sucking vectors, it was also called swamp fever. Soldiers especially suffered during times of peace and civil wars and the builders of the Panama Canal. This virus is still raging in African countries; several million people die there every year from malaria. It turned out that Pharaoh Tutankhamun died from malaria - this was proven by DNA analysis, as well as medicines found in his tomb.

Tuberculosis. One of the oldest viruses found on earth. It turns out that even after thousands of years, tuberculosis was preserved in Egyptian mummies. In different historical eras, the epidemic destroyed millions of people. Just think - tuberculosis did not subside for 200 years, from 1600 to 1800. Despite modern antibiotics and vaccinations, doctors have not been able to completely protect people from the risk of the disease.

Cholera. An entire work, “Love in the Time of Cholera,” by the outstanding Colombian writer Gabriel García Márquez, is even dedicated to this epidemic. The Industrial Revolution led not only to progress, but also to an outbreak of cholera. Dirty Europe was suffocating in the stench, mired in disease, and traders transported the cholera virus to the East, Asia and Africa. Scientists believe that the virus was originally transmitted to humans from monkeys. And the emergence of factories, industrial waste and landfills caused the emergence of coli at a later time. In addition, there was still no normal sewerage and water supply system. This scourge of dirty cities and countries still puts entire nations at risk of extinction.

AIDS. The sexual revolution of the 1980s led to the spread of one of the most terrible epidemics on earth - AIDS. Today this disease is called the plague of the 20th century. Promiscuity, drugs and prostitution contributed further more development pandemic. But this virus came from the poverty-stricken cities of Africa, generated by slums and unemployment. Millions of people become victims of the disease every year. To this day, doctors are unsuccessfully struggling to invent a cure or vaccine against AIDS. Due to the fact that a fifth of those infected hide or do not know about their own illness, it is impossible to establish the exact number of people infected with HIV. A striking example The lead singer of the group “Queen”, Freddie Mercury, who died in the prime of his life, completely alone, became a ruined talent due to his own stupidity.

Yellow fever. Africa has always been the most desirable continent in terms of slave labor and the most dangerous continent due to severe epidemics. Along with the slaves, yellow fever came to America from the “dark continent,” which wiped out entire settlements. Napoleon also tried to establish his own colony in North America, but the number of casualties among the soldiers was so great that the French emperor abandoned his idea in horror and sold Louisiana to the Americans. There are still outbreaks of the epidemic yellow fever found in African countries.

Typhus. It was especially common among the military, which is why the epidemic was given the nickname war or camp fever. This disease decided the outcome of military events, or even the war itself, tilting the balance in one direction or another. Thus, during the siege of the Moorish Granada fortress by Spanish troops in 1489, the pandemic destroyed 17 thousand soldiers out of 25 thousand in just a month. Typhus, which raged for several centuries, did not allow the Moors to be expelled from Spain.

Polio. A terrible epidemic disease that children are especially susceptible to. In the Middle Ages, due to the lack of any normal sanitary and hygienic standards, millions of children died. In the 18th century, the virus matured significantly and began to infect adults. Doctors were never able to find effective medicine against polio, the only solution to this day is vaccination.

It turns out interesting - humanity has so many problems, but instead of working together to try to invent means and methods of treatment, biologists are working to create biological weapons based on existing viruses. Has the bitter experience of past centuries, when entire cities died out, taught us nothing? Why do you need to turn medicine against yourself? Just think, just recently a terrible scandal broke out in America when a cleaning lady found a capsule with a biological weapons virus in a closet at a research institute, which they were going to throw away as unnecessary! But the evil contained in this capsule is capable of destroying most of the world's population! And an increasing number of countries are trying to increase their own power through the possession of biological weapons. So the recent outbreak of Ebola fever in some African countries is attributed to the hands of biological weapons developers. Although in fact this epidemic has previously affected not only people, but also primates. Today, the number of victims is already in the thousands, and humanity does not have a mass production of medicines and vaccines against pestilence.

But the history of biological weapons goes back to ancient times. Even the ancient Egyptian commander used poisonous snakes to fire pots of them at enemies. In various wars, opponents threw the corpses of people killed by the plague into enemy camps to capture fortresses or, conversely, lift the siege. Terrorists sent letters infected with anthrax to residents of the United States. In 1979, an anthrax virus leak from a Sverdlovsk laboratory killed 64 people. It is interesting that today’s progressive medicine, which works miracles, cannot withstand modern epidemics, for example, a virus bird flu. And the recent increase in local wars for the redistribution of territories, global processes of labor migration, forced relocation, poverty, prostitution, alcoholism and drug addiction are aggravating the situation.

When science fiction films or books depict the end of the world, one of its signs is necessarily mass epidemic or pandemic. There have been so many cases in the history of mankind when diseases took millions of lives that people began to believe that the end of the world was really near. Cholera, plague, smallpox, AIDS - unfortunately, it cannot be said that these epidemics are a thing of the distant past and no longer pose a danger. In our review - the deadliest of all epidemics.

The cause of the depopulation of Europeans in the 14th century was the bubonic plague, or “Black Death”. It claimed the lives of about 75 million people, a third of the population of Europe. The plague devastated entire cities. Its carriers were rat fleas and ticks. Doctors had to work at risk own life. They wore special uniforms made of fabric impregnated with wax and masks with long beaks, which contained aromatic substances that supposedly prevented infection and masked the smell of decomposing bodies. Up to the 19th century. this terrible disease practically resistant to treatment.

One of the most dangerous killers in human history was smallpox. In the 8th century. Smallpox killed 30% of Japan's population. This disease led to the depopulation of Northern and South America as a result of European colonization and only in the twentieth century. claimed between 300 and 500 million lives. Since 1950, vaccinations against smallpox have begun throughout the world.

A viral disease that continues to kill human lives and in our day, measles. It destroyed the Inca civilization and left vast areas of Central and South America deserted. The total death toll from measles is more than 200 million.

The real scourge of dirty cities and countries is cholera. In the 19th century it claimed 15 million lives. The main vector of the disease was water contaminated with feces. With proper sanitation and disinfection, the disease can be controlled.

Between 1918 and 1920 The H1N1 influenza virus epidemic has swept the entire globe. In just 2 months, the Spanish Flu claimed 20 million lives, and the total death toll was between 50 and 100 million people worldwide. The pandemic was global in nature, even infecting people on islands in the Pacific Ocean.

Malaria has been a direct threat to humans since ancient times - Pharaoh Tutankhamun died from it. Although it is now limited to tropical and subtropical regions of the planet, it was once common in Europe and North America. Every year, between 300 and 500 million cases of malaria occur worldwide. The infection is transmitted through mosquito bites.

AIDS is called the plague of the twentieth century

Many of these tragic events were documented by photographers, such as the Spanish Flu outbreak and others.

Throughout their existence, people have been repeatedly subjected to various diseases, which developed into large-scale forms and turned into epidemics. Nothing has ruined people more than harmful to the human body microbes Outbreaks of epidemics have claimed the lives of millions of people, and their threat has not lost its relevance today.

According to WHO statistics, 10 diseases have been defeated throughout history, but some diseases and their outbreaks still exist today. In terms of the number of epidemic victims, Smallpox ranks first, followed by influenza, plague, malaria and tuberculosis. An unlimited number of sick people is considered a sign of an epidemic outbreak if even 5% of people are sick in a limited area. And if the disease has spread beyond its borders, then it is already considered a pandemic.

Smallpox

In first place is the disease Smallpox. Smallpox, early name – Black smallpox – is viral infection. Statistics deaths – 300 million people throughout the history of mankind. Smallpox affects only humans and is highly contagious. This disease does not occur individually, but only in outbreaks of epidemics.

Initial symptoms of smallpox: heat, cough, pain all over the body, later a rash appears all over the body, pulmonary edema, even death.

The terrible disease has its roots in ancient India; the first outbreak occurred many thousands of years ago. In Russia, the first epidemic was recorded in the 17th century in Siberia. Even Peter II died from this terrible disease.

In Russia, forced vaccination of people began in 1936, thereby marking the beginning of the end of the epidemic. But the outbreak repeated in 1959; the famous artist Alexei Kakareikin brought the disease with him during a trip to India. Then they even forgot about this disease.

Influenza is the second most common cause of death. This infectious disease affects Airways. WITH frequent intervals is in the nature of an epidemic. IN modern world There are more than 2,500 strains of the influenza virus.

The most common symptoms of influenza are: elevated temperature, body pain, cough and lethargy. Also, some types of influenza cause complications in the form of pneumonia and even meningitis, even death. The virus is capable of mutating. In general, 3 types of influenza virus have been discovered: A, B and C.

The first outbreak of an influenza epidemic was recorded in 1580. The second, known as the “Spanish Flu,” which occurred in 1918, was characterized by lightning speed and a high number of deaths.

For all time, according to statistics, deaths from the influenza virus are about 200 million people.

Plague is one of the most terrible infectious diseases that has claimed lives from 75 to 200 million people throughout the history of mankind. This disease is characterized by its contagiousness and big amount fatalities. During infection, plague bacteria affect the lymph nodes, lungs and other organs until the development of sepsis.

There have been 3 major major plague outbreaks throughout history. Then people could not even imagine that the original carriers of these bacteria were fleas that lived on the bodies of rats, and later the plague virus mutated and spread through the air from person to person. The plague virus was even used as a biological weapon; it was first used by Zhdoni Bek, a descendant of Genghis Khan, during the capture of Caffa.

The plague vaccine was first invented by the Odessa epidemiologist Vladimir Khavkin, which was tested on herself by the Soviet bacteriologist Magdalina Petrovna Pokrovskaya. The beginning of the end of the plague occurred in 1947 after Soviet doctors used a vaccine called Streptomycin, developed at the Research Institute of Epidemiology and Hygiene of the Red Army.

Malaria

Malaria is a vector-borne infectious disease. Infection occurs through the bites of malaria mosquitoes. General symptoms, characteristic of this disease: fever, enlarged spleen and liver, chills and anemia.

People die every year from outbreaks of this disease. about 2 million people. The first appearances were recorded several centuries ago, and the first medicine was created in China in 340. However, a very large percentage of deaths occur due to this terrible disease.

In the twentieth century, epidemics of syphilis were overcome by infecting a patient with malaria; the high temperature during infection with this disease completely killed the syphilis bacteria.

There are several types of malaria: tropical, four-day and three-day (ovale malaria). Currently, trials are underway to develop a vaccine against malaria. Last year, in the United States, scientists finally created a drug against malaria and tested it on mice; now the drug is being prepared for testing on humans.

A widespread disease, it affects not only people, but also animals. Terrible disease, affecting the lungs and transmitted through the air. The first recorded case was in 1907.

Symptoms characteristic of tuberculosis are cough with sputum, hemoptysis, later weakness of the body, sweating, and fever are noted.

Annually 3 million people dies from complications after tuberculosis. A third of the world's population is infected, of which 300 thousand people are in Russia every year and 35 thousand people die.

Over the years, many vaccines have been created and a huge number of diseases have been completely defeated, and this is excellent progress in the history of mankind. There are still many mysteries and secrets for people about diseases for which vaccines have not yet been invented, for example, such as AIDS, cancer and many others. If medicine had not progressed, people would still die from syphilis and plague. Thanks to the intelligence and experience of scientists and doctors, humanity has not ceased to exist.