Over the centuries the development of human society has formed a special branch of scientific knowledge dedicated to the prevention and control of infectious diseases. History shows that in the course of its evolution, the damage to humanity from infectious morbidity exceeds by many orders of magnitude those from social and natural disasters. Specific terms have emerged that identify epidemics as infectious diseases with “black pages” in the life of human society.
With the progress of historical progress, disparate scientific ideas have evolved into a science – epidemiology, which studies the patterns of the epidemic process, in the interests of preventing and combating infectious diseases.
With the expansion of prevention boundaries beyond infectious pathology, there was a need for a population approach in the study of not only infectious but also non-infectious diseases. At present, general principles and methodological bases of population study of all diseases have been formulated. The concept of non-infectious epidemiology has emerged. Therefore now it is lawful to allocate:
– epidemiology as a general medical science;
– epidemiology as a science about the epidemic process.
Epidemiology as a general medical science studies the causes, conditions and mechanisms of the formation of the morbidity of the population by analyzing its distribution across the territory, among different population groups and in time for the development of methods of disease prevention.
In the future, we will focus on the epidemiology of infectious diseases.
As the most important division of medicine, epidemiology originated in ancient times. With the advent of man and its contact with animals, contagious diseases of people appeared. Accordingly, since ancient times, mankind has been trying to find ways to prevent the spread and spread of contagious diseases. At first, epidemiological knowledge was based on random (empirical) guesses and observations.
But, nevertheless, this knowledge accumulated and led in the subsequent to the creation of epidemiology as a science. In the history of epidemiology, somewhat conventionally, the following periods can be distinguished:
Ancient or “pre-Hippocratic” – XII-V centuries. BC. – a period of empirical conjectures and the accumulation of certain facts.
Hippocratic – V-IV centuries. BC. until the XV-XVI century. – first thought about the cause (etiology) of mass illnesses, the doctrine of the constitution of places and years.
Posthippocraticand prebacteriological- XV-XVI v.v. until the second half of the XIX century. – D. Frakostoro, T. Sidenheim, D.S. Samoilovich, E. Jenner, and others.
Bacteriological – the second half of the XIX century. up to the 1st quarter of the 20th century. – L. Pasteur, R. Koch, I.I. Mechnikov, N.F. Gamaleya, D.I. Ivanovsky and others.
Modern or scientific epidemiology – from the 1st quarter of XX century.to the present day – the emergence of epidemiology as a science (DK Zabolotny, LV Gromashevsky, II Elkin, VD Belyakov, etc.).
Ancient period.
A few thousand years before the new era, ancient peoples discovered the first attempts of anti-epidemic and preventive measures. So, in the ancient Chinese medicine, since the XII century BC.e. in a special group, epidemic diseases were allocated and even measures were taken to isolate infectious patients. In ancient China and in some other eastern countries, variolation was used – artificial vaccination of smallpox, by inhaling dried or chopped crusts from convalescents, or putting children’s clothing impregnated with pockmarks and air dried in such a way as to obtain lifelong immunity to the disease. In India, the most ancient manuscript on palm leaves was discovered, which tells of anthrax, cholera and dysentery. In ancient Chinese medicine, Indian Veddah, the laws of Mann, there were indications of the fight against infectious diseases, the development of the fundamentals of hygiene and sanitation. There was a provision on the removal of lepers outside the city limits, they had to wear special clothes, a bell around their necks so people would know that he was a leper, they were forbidden to attend mass events, markets, etc. There is a mention of self-isolation and the rules of evacuation from plague cities. Then it was pointed out that the plague is the result of a previous incidence that rabies in a person begins with a bite to a rabid animal, leprosy as a result of a prolonged contact of a healthy person with a sick person. It was pointed out that cholera occurs in the valleys of large rivers and in the hot season.
Thus, all this already in the most ancient times led to many useful empirical conclusions. So, for example, it was known that the patient is contagious and that from it one can get infected not only by contact, but also through things, air.
By this time, the notion of not only the infectiousness of patients, but also of immunity, is relevant. The well-known ancient Greek historian Thucydides (460-400 BC) wrote that during the plague “who suffered the disease … was already safe. For twice no one fell ill, at least deadly. ” Even then, people who had suffered the plague were attracted to caring for the sick, burial of corpses of people who died from the plague.
The cult of purity was propagated in the ancient world, measures of personal and public hygiene were systematically carried out, baths and swimming pools were built. There was frequent change of linen, extermination of insects and mice.
Hippocratic period.
The beginning of the doctrine of epidemics was laid down in the writings of Hippocrates (460-377 BC), who wrote The Seven Books on Epidemics, Lucretia (1st century BC), Celsius (1st c. BC), Pliny (23-79 AD), Abu Ali ibn-Sina (Avicenna, 980-1037), and others.
Thus, since the time of Hippocrates, we can talk about the birth and development of epidemiological science. Summarizing the disparate data on the development of epidemics in different places and at different times, Hippocrates introduced the concept of the epidemic constitution of places and years, i.e. in modern interpretation it corresponds to the concepts of “risk territory” and “time of risk”. He was, in fact, the ancestor of medical geography. Hippocrates studied the causes of disease. They divided them into general, mainly external (the influence of the seasons, territory, climate, air, water, nutrition, etc.) and individual (sex, age, heredity, temperament, habits, lifestyle, etc.).
The merit of Hippocrates is that he paid attention to the development of questions of the etiology of mass (infectious) diseases. In his works, a miasmatic hypothesis of the emergence of contagious diseases was put forward. According to it, diseases and epidemics occur when inhaled harmful “miasm” (Greek miasma – contamination) – “pathogenic substances” that arise in the bowels of the earth, in water or in the air, i.e. non-living substances. Later, a second concept was proposed, according to which – contagious diseases and epidemics arise as a result of infection of people and animals with harmful beings – “contagiumvivum”, transmitted by various ways from sick people to healthy (contagious hypothesis).
As the prominent Russian epidemiologist V.A. Bashinin, in epidemiology in the next 2000 years, more original views were not expressed than the views of Hippocrates.
The great physician and scholar of the East, Abu Ali ibnSina (Avicena, 980-103 /), in his work The Canon of Medical Science, suggested that smallpox, measles, leprosy, plague and other contagious diseases are caused by invisible small living beings transmitted through air and water.
In the second half of the Middle Ages, since the eleventh century, the spread of epidemics in Europe and Asia was associated with crusades. At this time, smallpox, leprosy and other diseases became an unusual occurrence.
In the era of feudalism, which followed the fall of the ancient world, the rudiments of personal and public hygiene, as well as the prevention of disease, were lost. The development of crafts and manufactories led to the emergence of large cities with an exceptionally unfavorable sanitary and hygienic state in them, with the crowding of the poor in poor dwellings. Therefore, epidemic diseases – plague, smallpox, leprosy, typhus and typhoid, syphilis and others – spread in Europe very widely, and the development of navigation and numerous wars contributed to the rapid spread of these diseases to many countries of the world. So, in the XIV century. In Europe, 25 million people or a quarter of the population died of the plague called “black death”, extensive devastating epidemics of smallpox, typhus and other illnesses raged, prompting authorities and doctors to develop protective measures. In 1374 in Italy in Venice for the first time were introduced quarantines, the effectiveness of which was confirmed by practice.
Post-Hippocratic or anteriologic period.
Again, there are debates about the causes of epidemic diseases between miasmatics and contagionists. Further development of the contagionist hypothesis was received in the work of the Italian physician GirolamoFrachostoro (1478-1553) “On contagion, contagious diseases and treatment” (1546). It has systematized disparate information and created a whole doctrine of the causes of contagious diseases, their classification has been given, and some clarity has been made about their nature and ways of transmission. He described the natural smallpox, plague, measles, rabies, typhus, leprosy, malaria and other diseases, expressed a brilliant assumption about the role of living germs (embryos) in their occurrence, endowing them with the ability to reproduce and transmit to healthy people. Diseases are transmitted by contact (touch) – direct and indirect way, through the things of the patient and at a distance even through the air. J. Frachostoro wrote: “The seeds produce not only this, but also much more: they create similar ones to themselves other seeds, as if the offspring, which, being transferred to another, brings in it contagios.” These seeds can be retained on objects of the external environment and form “foci”. He was the first to make an attempt to understand the relationship between the epidemiology and the clinic of infectious diseases. Not knowing microbiology, he wrote about the specificity of disease pathogens, that specific “seeds” can have “different potential effects”, and also suggested the variability of species (different “seeds”), their evolution under the influence of external factors. He gave a large place to the role of polluted air in the spread of certain mass diseases. All this contributed to the subsequent scientific development of epidemiology.
A great role in this direction after 100 years played a prominent English physician Thomas Sydenham (1624-1689). Although he was a follower of miasmatics, he supported the teaching of “epidemic constitutions of places and years”. He took another step forward in the study of the clinic and the epidemiology of some infectious diseases. He described the clinical picture of whooping cough, measles, scarlet fever, smallpox and some others, and also sought to determine the social role of epidemiological views and epidemiology in general. Many of his scientific conclusions and practical actions were erroneous, as a follower of miasmatics, but at the same time anti-epidemic actions indicate the greatest foresight of the scientist and the enormous impact of his conclusions on the development of epidemiology.
The founder of epidemiology in Russia was the outstanding epidemiologist and scientist DaniloSamoilovichSamoilovich (1742-1805), who devoted his entire life to studying the causes, ways of spreading and preventing plague and some other infections. A personal participant in the struggle against the plague in Moscow in 1771-1772, he conducted a number of remarkable studies on epidemiology and the fight against it. He was convinced that “the plague is caused by a special and absolutely excellent creature”, so for the first time he attempted to apply a microscope to detect live pathogens of the plague. D.S. Samoilovich was confident that after the illness he had been developing, immunity to the disease developed, for during one epidemic people do not get sick with a plague twice, so to care for the sick, he tried to recruit nurses from among those who had recovered. In addition, D. Samoilovich studied the variability of the causative agents of the plague. He understood that in the recovering patients with the bubonic form of the disease in ripened and uncovered buboes, the contagious beginning is in a weakened form. Therefore, he made an attempt for the first time to conduct antiplague prophylactic vaccinations, using allocation from buboes from convalescents. For the protection of infection with plague in contact and / or through household items, he recommended to wear protective clothing, as well as the first to use a prototype of disinfection and disinfestation – fumigation method – using a special composition of the powder, the proposed KasyanJagielski, for disinfection of premises, where they were sick and the clothing of patients , consisting of various materials (fur, wool, silk, cotton fabric, etc.). For the first time in the world had the experience of self-infection with plague, to prove the existence of immunity after diseases, and wore clothes of patients with plague after fumigation to prove her innocence after exposure to smoke.
Great credit belongs to D. Samoilovich on the organization of a quarantine and anti-epidemic service on the Black Sea coast. These studies and measures were the prototype for scientifically developed methods of disinfection, disinfection and prevention of infectious diseases by means of vaccination and quarantine. Trudy DS Samoilovychhave been translated into many European languages, and the scientist was elected an honorary member of 14 foreign academies and scientific societies, but, unfortunately, died ignorant doctor in Russia.
The end of the XVIII century. It was marked by a remarkable offer English physician E. Jenner (1749-1823) – a method of vaccination against smallpox (1796), using for this purpose the material harmless cowpox. This remarkable discovery allowed to save mankind from smallpox, which was eliminated in the world in 1977.
Bacteriological period.
It should be noted that epidemiology as a branch of practical medicine and scientific discipline began to form and accumulate scientific and practical material much earlier than microbiology. However, great discoveries in the field of microbiology, virology and immunology as a result of the works of L. Pasteur, R. Koch, I.I. Mechnikov, P. Erlich, D.I. Ivanovsky, N.F. Gamaleia and many other scientists greatly enriched and epidemiology, making a revolution in medicine in general. L. Pasteur (1822-1895) – the founder of the microbiological and epidemiological experiment. J. Lister at the anniversary of the microbiologist will say: “Pasteur plucked from our eyes the bandage, which for centuries prevented to see the essence of infectious diseases.” The greatest merit of L. Pasteur was not only in the fact that he discovered a number of pathogens of infectious diseases, he created the science of microbiology, but the special importance lies in the fact that he developed and proposed methods and means of struggle or specific prevention each time. Finally, L. Pasteur created and proposed a method of obtaining vaccines for the specific prevention of infectious diseases, which is an invaluable merit of Pasteur as a scientist before the world science and humanity. I.I. Mechnikov (1845-1916) discovered the phenomena of phagocytosis (1882), created a phagocytic theory of immunity (1883), which later together with P. Erlich created a harmonious theory of immunity, for which I.I. Mechnikov and P. Ehrlich in 1908 received the Nobel Prize. DI. Ivanovsky in 1892 discovered viruses, which created the science of virology, which made it possible to decipher the etiology of many infectious diseases.
Modern or scientific period.
The founder of modern epidemiology of infectious diseases is rightly considered to be DaniilKirillovichZabolotny (1866-1929), who in 1920 in Odessa opened the world’s first department of epidemiology, defined epidemiology, wrote the first textbook “Fundamentals of Epidemiology” in 1927. He studied epidemiology, distribution areas, sources of plague. He proved that rodents are a reservoir of plague in nature: marmots (Transbaikal marmot – tarabagan), ground squirrels, gerbils, jerboas, rats, etc. His works on studying epidemiology and prevention of cholera, syphilis, typhus and other infections became world famous.
L.V. Gromashevsky (1887-1980) established the Department of Epidemiology in 1928 in Dnepropetrovsk. He studied epidemiology and measures to prevent plague, typhus, cholera, viral hepatitis, various acute intestinal and other infections. L.V. Gromashevsky developed the doctrine of the epidemic process, created the theory of the mechanism of transmission of infections, the epidemiological classification of infectious diseases (1941), formulated the laws of epidemiology. All this was of great scientific importance for the development of epidemiology and practical – For the prevention and elimination of infections.
V.A. Bashenin (1882-1978) for the first time in the USSR described jaundice leptospirosis (1928), studied viral hepatitis, childhood and some other infections. He proposed to study the level, structure and dynamics of morbidity for disclosing the patterns of occurrence, distribution and prevention of them. He believed that epidemiology is a science not only about the patterns of the epidemic process of infectious diseases, but suggested studying and developing the epidemiology of non-infectious diseases (cardiovascular, cancer, silicosis, etc.) and, on the basis of this, to develop the prevention of diseases.
E.N.Pavlovsky (1884-1969) studied natural focal infections: leishmaniasis, tryponosomiasis, plague, tick-borne taiga spring-summer encephalitis and others. He created the theory of natural foci of some vector-borne infections (1938-1939), most of which are wild animals, mainly rodents, and carriers of insects and arthropods. He and his numerous students and followers developed measures to combat and prevent these diseases. His ideas enabled him to formulate the doctrine of the so-called epidemiological (medical) geography.
K.I. Scriabin (1878-1972) created new directions in the biological, medical and veterinary sciences, created the science of helminthology. He created the first department of parasitology and invasive diseases in the Danish Veterinary Institute in 1917, and in 1932 in Moscow – the world’s first institute of helminthology and ten years later he headed this research team. Scientists created the helminthological service of the country – a wide network of specialized research and practical institutions. He owns the idea and created a new method of devastation – the complete destruction of helminths at all stages of development, in all places of stay, which became the basis of the fight against helminthiases. He was elected a valid and honorary member of 12 foreign academies and scientific societies.
V.D. Belyakov (1921-1996) developed theoretical and practical problems of general and military epidemiology. He developed the principles of epidemiological diagnosis and effectiveness of anti-epidemic measures, prevention, as well as private epidemiology: dysentery, diphtheria, Ku-fever, streptococcal (angina, scarlet fever, glomerulonephritis, rheumatism), nosocomial infections and many others. He created a theory of self-regulation of parasitic systems, developed questions of molecular epidemiology.
The development of epidemiology of infectious diseases and measures to combat them was facilitated and facilitated by the scientific and practical activities of many epidemiologists: M.N. Soloviev, G.V. Vagralika, I.I. Rogozin, I.I. Elkina, R.Kh. Yafaev and others, and in Belarus – N.I. Volvacheva, N.I. Lebedeva, V.I. Votyakova, G.N. Chistenko, L.P. Titov and others.
Conclusion
The history of mankind was constantly accompanied by epidemics of infectious diseases, which led to innumerable victims. The rationale and the subsequent development of measures for the prevention and control of epidemics were an urgent necessity in the process of human evolution. In modern conditions, epidemiology acquires a fundamentally different quality, allowing it to approach the exact sciences, through the introduction of new research methods. There are serious achievements of this discipline in reducing infectious diseases.
Infectious diseases for many years occupy the first place. And if so, the doctor – a specialist of the sanitary and epidemiological service should fully know the system of measures for antiepidemic care of the population and practically master the methodology and conduct of basic measures to reduce the infectious morbidity.
