Major infectious diseases and their prevention. Outline of life safety on the topic: "Infectious diseases, their classification and prevention"

Infection (lat. infection) infectious diseases- This is a group of diseases that are caused by specific pathogens: pathogenic bacteria, viruses, protozoa, fungi. !!! Infectious diseases account for % of total number all human diseases.

There are periods of disease development: The incubation period is the period of time from the moment of infection to the appearance of the first clinical symptoms of infection Initial period- this is the time from the moment the first signs of the disease appear to its peak. The peak period of the disease is the appearance of signs characteristic of this disease, many symptoms can reach their maximum severity. The recovery period begins from the moment the severity of the manifestations of an infectious disease decreases.

Ways of spread of infections Fecal-oral intestinal infections. The microbe with feces, vomit of the patient gets on food products, water, dishes, and then through the mouth into gastrointestinal tract of a healthy person Fecal-oral This way all intestinal infections are transmitted. The microbe with feces, vomit of the patient gets on food, water, dishes, and then through the mouth into the gastrointestinal tract of a healthy person. viral diseases upper respiratory tract. The virus with mucus, when sneezing or talking, enters the mucous membranes of the upper respiratory tract of a healthy person. Airborne This way all viral diseases of the upper respiratory tract spread. The virus with mucus, when sneezing or talking, enters the mucous membranes of the upper respiratory tract of a healthy person. The main ways of transmission of infection

Contact or contact-household In this way, most of the infection occurs sexually transmitted diseases with close contact of a healthy person with a sick person Contact or contact-household Infection with most venereal diseases occurs with close contact of a healthy person with a sick person Zoonotic Carriers of zoonotic infections are wild and domestic animals. Infection occurs through bites or close contact with sick animals. Zoonotic Carriers of zoonotic infections are wild and domestic animals. Infection occurs through bites or close contact with sick animals. Ways of spread of infections Liquid Characteristic for blood infections. The carriers of this group of diseases are blood-sucking insects: fleas, lice, ticks, mosquitoes, etc.

Ways of infection are diverse: the most frequent food, most often when eating meat of animals and birds, as well as eggs. Once in the body, Salmonella settle in small intestine and secrete a toxin that contributes to: - loss of water through the intestines - impaired vascular tone - damage nervous system

Tuberculosis is an infectious disease that is transmitted to a healthy person from a sick person when coughing, talking, sneezing. html The causative agent is Koch's bacillus (bacterium)

Tuberculosis can affect any organ, but the lungs are predominantly affected.

Signs of tuberculosis: cough for more than two weeks weight loss increased body temperature decreased appetite chest pain shortness of breath night sweats weakness

Onychomycosis is a fungal disease of the nail. 10 - 15% of the population suffers from this disease, and among people over 60 years old - almost 30%. The cause of onychomycosis can be household items: bath mats, washcloths, manicure accessories, shoes, when visiting the pool, bath, sauna, shower, gym.

One boy fell ill, And then another after him, For some reason, quarantine was announced in our class. S. Mikhalkov Quarantine is…. ... a set of measures to stop the spread of infection

Among the preventive measures, an important place is occupied by the formation of the immunity of the body of children and the creation of their immunity to various diseases by carrying out: - preventive vaccinations - tempering procedures It is very important to observe personal hygiene!

Nizhnedevitskaya General Educational Gymnasium

abstract

Topic: Infectious diseases

Performed:

11th grade student

Elfimova T.

Teacher:

Kuznetsov G.I.

Nizhnedevitsk 2002

Plan.

1. Infectious diseases. Introduction.

2. The reasons for their occurrence. transmission mechanism.

3. Classification of infectious diseases.

4. The concept of immunity.

5. Methods of emergency and specific assistance.

6. Conclusion.

7. List of references.

Infectious diseases. Introduction.

The idea of the contagiousness of such diseases as plague, cholera, smallpox and many others, as well as the assumption of the living nature of the infectious principle transmitted from the sick to the healthy, existed even among ancient peoples. The plague of 1347-1352, known in history as the Black Death, further reinforced this notion. Particularly noteworthy was the contact spread of syphilis, which appeared in Europe in the Middle Ages, as well as typhus.

During this period of the development of medicine, the symptoms of diseases, their contagiousness are mainly described; there are first reports of people's immunity to a previously transferred disease. However, the development of medical knowledge, as well as other sciences, in the conditions of the Middle Ages was very difficult for the domination of the church, "church dogma was the starting point and basis of all thinking."

The doctrine of infectious diseases developed along with achievements 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 beings invisible to the naked eye belongs to the Dutch naturalist Antonio van Leeuwenhoek (1632-1723), who discovered the world of the smallest creatures unknown to him. But even after this discovery, microbes have not yet been finally recognized as the causative agents of infectious diseases, although individual researchers have tried to establish their role. So, the Russian doctor D.S. Samoilovich (1744-1805) proved the contagiousness of the plague and disinfected the belongings of patients, and also tried to vaccinate against this disease. In 1782, he searched for plague pathogens using a microscope.

The middle of the 19th century was characterized by the 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 put into practice sterilization and pasteurization. Pasteur discovered the pathogens of chicken cholera, septicemia, osteomyelitis, etc. Pasteur developed a method for preparing vaccines by artificial weakening (attenuation) of virulent microbes for the prevention of infectious diseases - a method that is still used today. They have prepared vaccines against anthrax and rabies.

AT further development microbiology, a great merit belongs to the German scientist Robert Koch: (1843-1910). The methods of bacteriological diagnostics developed by him made it possible to discover the causative agents of many infectious diseases.

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

Simultaneously with the development of medical microbiology, the clinical knowledge of physicians improved. In 1829, Charles Louis described in detail the clinic of typhoid fever, singling out this disease from the group of "fever" and "fever", which previously combined all diseases that occurred with high temperature. In 1856, typhus was isolated from the group of "fever diseases", in 1865 - relapsing fever. Great merits in the field of the study of 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) singled out “infectious jaundice” (ictero-hemorrhagic leptospirosis) as an independent disease. Wonderful pediatrician prof. N. F. Filatov first studied and described 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, a coherent doctrine of immunity (immunity) in infectious diseases was created. Discovered by I. I. Mechnikov in 1882-1883. the phenomenon of phagocytosis, which marked the beginning of the doctrine of immunity, opened up prospects in the prevention and treatment of infectious diseases. These discoveries made it possible to develop and apply in the clinic serological studies(reactions of agglutination, precipitation, etc.) for laboratory diagnostics of infectious diseases. Great merit in the development of immunology and the theory of infection belongs to N. F. Gamaleya (1859-1949), who also discovered the phenomena of bacteriophagy.

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

The merit of Soviet scientists in the study of questions specific prevention infectious diseases. Currently, highly effective live vaccines against brucellosis are being used with success. smallpox, anthrax, tularemia, plague, leptospirosis and some other diseases. In 1963, Soviet scientists A. A. Smorodintsev and M. P. Chumakov were awarded the Lenin Prize for the development of a polio vaccine.

Various methods have been used for the treatment of infectious diseases since ancient times. chemical substances. Before others began to be used for the treatment of malaria infusion of cinchona bark, and since 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 were obtained sulfa drugs(streptocide, sulfidine, etc.), which marked new period in the treatment of infectious patients. Finally, in 1941, the first antibiotic, penicillin, was obtained, the importance of which can hardly be overestimated. For the production of penicillin, the work of domestic scientists V. A. Manassein, A. G. Polotebnov, and the English microbiologist Alexander Flemming were important. In 1944, streptomycin was obtained, in 1948 - 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 now significant achievements in the field of their clinical study. Only in recent years, several new infectious diseases have been discovered and studied, mainly viral etiology. Much attention is paid to pathogenesis, clinical features the current course of infectious diseases, in particular among those vaccinated; improved methods of treatment.

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

The reasons for their occurrence. transmission mechanism.

The process of the spread of infectious diseases in the human team is a complex phenomenon, which, in addition to purely biological factors (properties of the pathogen and the state of the human organism), is greatly influenced and social factors: the material condition of the people, population density, cultural skills, the nature of food and water supply, profession, etc. The process of the spread of infectious diseases consists of three interacting links: 1) the source of infection that releases the microbe-causative agent or virus; 2) the mechanism of transmission of pathogens of infectious diseases; 3) the susceptibility of the population. Without these links or factors, new cases of infection with infectious diseases cannot occur.

The source of infection in most diseases is a sick person or a sick animal, from whose body the pathogen is excreted by one or another physiological (exhalation, urination, defecation) or pathological (cough, vomiting) way.

The way the pathogen is isolated from the diseased organism is closely related to the place of its predominant location in the body, its localization. So, with intestinal infectious diseases, pathogens are excreted from the intestine during defecation; when the respiratory tract is affected, the pathogen is excreted from the body when coughing and sneezing; when the pathogen is localized in the blood, it can enter another organism when bitten by blood-sucking insects, etc.

At the same time, it should be taken into account that the intensity of the release of pathogens in different periods of the disease is different. In some diseases, they begin to be released already at the end of the incubation period (measles in humans, rabies in animals, etc.). But the greatest epidemic significance in all acute infectious diseases is the height of the disease, when the release of microbes, as a rule, is especially intense.

In a number of infectious diseases (typhoid fever, paratyphoid fever, dysentery, diphtheria), pathogens can be intensively isolated during the recovery period (convalescence).

Sometimes, even after recovery, a person may for a long time remain a source of infection. Such people are called bacteria carriers. In addition, there are so-called healthy bacteria carriers - people who either did not get sick themselves or suffered the disease in the mildest form, in connection with which it remained unrecognized, but became bacteria carriers.

A bacteria carrier is a practically healthy person, but carrying and releasing pathogens. Acute carriage is distinguished, if it lasts 2-3 months, as in typhoid fever, and chronic, when a person who has been ill for decades releases the pathogen into the external environment. The discharge may be constant, but more often it is intermittent. Apparently the greatest epidemiological danger is posed by bacteria carriers, as well as patients with obliterated, atypical, light forms diseases, with whom they do not go to the doctor, carrying the disease on their feet and scattering pathogens around them (this is especially often observed in patients with influenza and dysentery).

transmission mechanism. After the pathogen is released from the source of infection (infected organism) into the external environment, it can die or remain in it for a long time until it gets to a new individual. In the chain of movement of the pathogen from the sick to the healthy, the length of stay and the ability of the pathogen to exist in the external environment are of great importance. It is during this period that pathogens - microorganisms - are most accessible for exposure to them, they are more easily destroyed. Many of them are detrimental to the sun's rays, light, drying. Very quickly, within a few minutes, the pathogens of influenza, epidemic meningitis, and gonorrhea die in the external environment. Other microorganisms, on the contrary, have adapted to maintain viability in the external environment for a long time. For example, the causative agents of anthrax, tetanus and botulism in the form of spores can persist in the soil for years and even decades. Tuberculous mycobacteria remain for weeks in a dried state in dust, sputum, etc. In foodstuffs, for example, in meat, milk, various creams, the causative agents of many infectious diseases can live long time and even reproduce. The degree of stability of pathogens in the external environment is of great importance in epidemiology, in particular in the selection and development of a set of anti-epidemic measures.

In the transmission of the infectious principle (pathogens), various environmental objects participate - water, air, food, soil, etc., which are called transmission factors. Ways of transmission of pathogens of infectious diseases are extremely diverse. They can be grouped into four groups depending on the mechanism and routes of infection transmission.

1. Contact way of transmission (through the outer cover) is possible in cases where pathogens are transmitted through contact of the patient or his secretions with a healthy person. Distinguish direct contact, e. one in which the pathogen is transmitted by direct contact of the source of infection with a healthy organism (bite or saliva of a person by a rabid animal, transmission of venereal diseases by sexual by i-t. d.), and indirect contact in which the infection is transmitted through household and industrial items (for example, a person can become infected with anthrax through a fur collar or other fur and leather products contaminated with anthrax bacteria).

By indirect contact, only infectious diseases can be transmitted, the pathogens of which are resistant to environmental influences. Anthrax and tetanus spores, which sometimes persist in the soil for decades, can serve as an example of the long-term preservation of microbes with indirect contact.

2. Great importance in the transmission of infectious diseases has a fecal-oral transmission mechanism. In this case, pathogens are excreted from the body of people with feces, and infection occurs through the mouth with food and water contaminated with feces.

The food way of transmission of infectious diseases is one of the most frequent. Both pathogens of bacterial infectious diseases (typhoid fever, paratyphoid fever, cholera, dysentery, brucellosis, etc.) and some viral diseases (Botkin's disease, poliomyelitis, Bornholm's disease) are transmitted this way. In this case, pathogens can get on food. different ways. The role of dirty hands does not require explanation: infection can occur both from a sick person or a bacteria carrier, and from people around who do not follow the rules of personal hygiene. If their hands are contaminated with the faeces of a patient or a carrier containing pathogens, then during the processing of food, these persons can infect them. Intestinal infectious diseases are therefore called diseases of dirty hands.-

Infection can occur through infected animal products (milk and meat of brucellosis animals, animal meat or duck eggs containing salmonella bacteria, etc.). Pathogens can get on animal carcasses when cutting them on tables contaminated with bacteria, improper storage and transportation, etc. It must be remembered that food products can not only retain microbes, but also serve as a breeding ground for the reproduction and accumulation of microorganisms ( milk, meat and fish products, canned food, various creams).

A certain role in the spread of intestinal infectious diseases with a fecal-oral mechanism of infection belongs to flies. Sitting on dirty bedpans, various sewage, flies pollute their paws and suck them into the intestinal tube pathogenic bacteria, and then transferred and isolated on food products and utensils. Microbes on the surface of the fly's body and in the intestine remain viable for 2-3 days. When eating contaminated food and using contaminated utensils, infection occurs. That's why flies extermination is not only a general hygienic measure, but also aims to prevent intestinal infectious diseases. The presence of flies in an infectious diseases hospital or department is unacceptable.

4. Close to food worth water way of transmission of infectious diseases. Cholera, typhoid and paratyphoid, dysentery, tularemia, brucellosis, leptospirosis, etc. can be transmitted through water contaminated with feces. The transmission of pathogens occurs both when drinking contaminated water, and when washing products, as well as when bathing in it.

5. Transmission through the air occurs with infectious diseases localized mainly in the respiratory tract: measles, whooping cough, epidemic meningitis, influenza, smallpox, pneumonic plague, diphtheria, scarlet fever, etc. Most of them are carried with droplets of mucus - drip infection. Pathogens transmitted in this way are usually unstable in the external environment and quickly die in it. Some microbes can also be transmitted with dust particles - dust infection. This route of transmission is possible only in infectious diseases, the pathogens of which are resistant to drying ( anthrax, tularemia, tuberculosis, Q fever, smallpox, etc.).

Some infectious diseases are spread by blood-sucking arthropods. Having sucked blood from a sick person or animal containing pathogens, the carrier remains contagious for a long time. Attacking then on a healthy person, the carrier infects him. Thus, fleas transmit plague, lice transmit typhus and relapsing fever, ticks transmit encephalitis, etc.

Finally, pathogens can be carried by flying insect transmitters; this is the so-called transmission path. In some cases, insects can only be simple mechanical carriers of microbes. In their body there is no development and reproduction of pathogens. These include flies that carry pathogens of intestinal diseases from feces to food. In other cases, development or reproduction and accumulation of pathogens occurs in the body of insects (louse - with typhus and relapsing fever, flea - with plague, mosquito - with malaria). In such cases, insects are intermediate hosts, and the main reservoirs, i.e., sources of infection, are animals or a sick person. Finally, the pathogen can persist in the body of insects for a long time, being transmitted germinally through the laid eggs (transovarially). So transmitted from one generation of ticks next virus taiga encephalitis. For some infections, soil is the route of transmission. For pathogens of intestinal infections, it is only a place for a more or less short stay, from where they can then penetrate into the sources of water supply; for spore-forming microbes - anthrax, tetanus and others wound infections- the soil is a place of long-term storage.

Classification of infectious diseases.

The causative agents of infectious diseases, as we saw above, are transmitted from patients to healthy people in various ways, that is, for each infection a specific mechanism of transmission is characteristic. The mechanism of infection transmission was put by L. V. Gromashevsky as the basis for the classification of infectious diseases. According to the classification of L. V. Gromashevsky, infectious diseases are divided into four groups.

I . Intestinal infections. The main source of infection is a sick person or a bacteriocarrier excreting with feces huge quantities pathogens. In some intestinal infectious diseases, it is also possible to isolate the pathogen with vomit (cholera), with urine (typhoid fever).

The infectious principle enters the body through the mouth along with food or drinking water contaminated in the external environment in one way or another. The mechanism of transmission of infectious origin in intestinal infections is schematically shown in Fig. one.

Intestinal infectious diseases include typhoid fever, paratyphoid A and B, dysentery, amoebiasis,

Rice. 1. Scheme of the mechanism of transmission of an infectious principle in intestinal infections according to L. V. Gromashevsky.

BUT - infected organism; B - healthy organ ism; 1 - the act of removing the pathogen (defecation); 2 - stay of the pathogen outside the body; 3 - the act of introducing the pathogen.

toxic infections, cholera, Botkin's disease, poliomyelitis, etc.

II . Respiratory tract infections. The source of infection is a sick person or a carrier. Inflammatory process on the mucous membranes of the upper respiratory tract causes coughing and sneezing, which causes a massive release of the infectious agent with droplets of mucus into the surrounding air. The pathogen enters the body of a healthy person by inhalation of air containing infected droplets (Fig. 2). Respiratory tract infections include influenza, infectious mononucleosis, smallpox, epidemic meningitis, and most childhood infections.

III . blood infections. The causative agents of this group of diseases have the main localization in the blood and lymph. Infection from the patient's blood can get into the blood

Rice. 2. Scheme of the mechanism of transmission of an infectious principle in respiratory tract infections (according to L. V. Gromashevsky).

BUT - infected organism; B - healthy body; 1 - the act of removing the pathogen (exhalation); 2 - stay of the pathogen outside the body; 3 - the act of introducing the pathogen (inhalation).

healthy only with the help of blood-sucking carriers (Fig. 3). A person with an infection of this group is practically not dangerous for others in the absence of a carrier. The exception is plague (pulmonary form), highly contagious to others.

The group of blood infections includes typhus and relapsing fever, tick-borne rickettsiosis, seasonal encephalitis, malaria, leishmaniasis and other diseases.

IV . Infections of the outer integument. The infectious principle usually penetrates through damaged outer integuments. These include venereal diseases sexually transmitted; rabies and sodoku, infection with which occurs when bitten by sick animals; tetanus, the causative agent of which enters the body through a wound; anthrax, transmitted by direct

Rice. 3. Scheme of the mechanism of transmission of an infectious principle in blood infections (according to L. V. Gromashevsky).

BUT - infected organism; AT- a healthy body; 1 - the act of removing the pathogen (sucking blood by arthropod vectors); 2 - stay of the pathogen in the body of the carrier (second biological host); 3 - the act of introducing the pathogen.

contact from animals or through spore-contaminated household items; glanders and foot-and-mouth disease, in which infection occurs through the mucous membranes, etc.

It should be noted that in some diseases (plague, tularemia, anthrax, etc.) there may be a multiple mechanism of infection transmission.

The concept of immunity.

Immunity - a property of the body that ensures its immunity to infectious diseases or poisons (in particular, to toxins). Immunity to infectious diseases comes in several forms.

1. Natural immunity occurs naturally, without conscious human intervention. It can be congenital and acquired.

a) Innate species immunity It is caused by congenital, inherited properties inherent in a given species of animal or person. it biological feature kind, thanks to which this species animals or humans are immune to certain infections. For example, a person does not suffer from fowl cholera or plague cattle, and animals do not suffer from typhoid or typhus, etc. Natural immunity is also observed in children in the first months of life to certain diseases - measles, scarlet fever, diphtheria, which is associated with the preservation of protective antibodies received by them from mothers who have had these diseases in the past diseases.

b) Acquired immunity occurs as a result of the body's reaction to the entry of a microbe or toxin into it. It occurs in a person as a result of an infectious disease, as well as with a latent infectious process.

Acquired natural immunity after some infectious diseases it persists for a very long time, sometimes for life (natural smallpox, typhoid fever, etc.), after others - for a short time (influenza, leptospirosis, etc.).

2. artificial immunity created by the introduction of vaccines and sera.

If the development of protective devices occurs in an active way in the body itself, then they speak of a active immunity. If protective substances are introduced into the body in finished form, they talk about passive immunity. Immunity resulting from past illness, - active immunity, since protective devices are developed by the body itself; immunity due to the transfer of protective substances through the placental route from mother to fetus is passive.

Artificial immunity is always acquired. Like natural, it can be active and passive. Artificial immunity is reproduced in a person (or in an animal) in order to prevent one or another infectious disease. Artificial active immunity is the result of an active reaction of the body to the introduction of a vaccine or toxoid (a toxin neutralized with formalin). Both natural and artificial acquired immunity are characterized by specificity in relation to the agent that caused it.

Artificial passive immunity is created when blood serum containing antibodies (actitoxins) is introduced into the body.

Preventive vaccines are introduced into the body of the person being vaccinated in various ways: subcutaneously, cutaneously, through the mouth.

Serums are usually administered in cases where it is assumed that infection has already occurred, and when it is necessary to ensure the rapid onset of immunity. For example, young children who have been in contact with someone with measles preventive purpose injected anti-measles gamma globulin.

Methods of emergency and specific assistance.

Treatment of infectious patients should be comprehensive and based on a thorough analysis of the patient's condition. In a book, especially a textbook, one can only recommend a treatment regimen for a particular disease, from which various patients may have some deviation due to the peculiarities given organism. The organism of each patient has its own individual characteristics, which determine the peculiarity of the course of the disease, which must be taken into account when prescribing treatment. Therefore, drugs and other therapeutic agents are prescribed only by a doctor after a thorough examination of the patient.

As a result of the interaction of the microbe with the patient's body, as we have already seen, the formation of immunity occurs, which must also be taken into account when prescribing treatment.

For implementation correct therapy a number of important conditions. First of all, specific anti-infective treatment must be provided, i.e. such treatment that is directed to the cause of the disease - pathogenic microbe introduced into the human body. To do this, it is necessary to know the causative agent of the disease in each specific case, i.e., to establish an etiological diagnosis. The next thing to consider is the sensitivity this pathogen to antibiotics and chemotherapy. It is necessary to take into account the conditions of the pathogen in the body; in which organ is it predominantly localized, is it surrounded by pus, is it available for the action of antibiotics, etc.

Specific antimicrobial agents include antibiotics, chemotherapeutic drugs, bacteriophage, specific sera and gamma globulins, vaccines, the action of which is directed either to the causative agent of the disease or to the toxins produced by it.

A microbe that has entered the body of a healthy person interacts with it, causing a number of changes: internal organs, metabolic disorder, accumulation in the body of substances alien to it, etc.

All this, in turn, requires appropriate treatment aimed at the main mechanisms of the pathological process.

Antibiotics

Antibiotics are substances produced by various organisms (fungi, bacteria, animal cells and plant organism) and having the ability to prevent the reproduction of microbes (bacteriostatic action) or cause their death (bactericidal action). The therapeutic use of antibiotics is based on the principle of antagonism between microbes. Currently, there are already more than 300 antibiotics, which differ from each other both in their physical and chemical properties, and by the ability to act on certain microbes. Highest value and distribution in the clinic of infectious diseases are penicillin, streptomycin, levomycetin, tetracycline drugs (biomycin, tetracycline, terramycin), erythromycin, mycerin, oleandomycin, oletethrin, sigmamycin, etc. Each antibiotic has a certain spectrum of antimicrobial action: it causes death or inhibits the development of only certain types of microbes and has no effect or has little effect on other types of microorganisms.

The use of antibiotics for the treatment of infectious patients was a major event in medicine: mortality decreased tenfold, the duration of illnesses was reduced, and complications began to occur much less frequently.

Antibiotics are administered into the patient's body in various ways: intramuscularly, intravenously, orally (by mouth) and occasionally into serous cavities.

Providing indispensable assistance in the treatment of infectious patients, antibiotics at the same time have a number of side properties, in some cases harmful to the body. When taking drugs inside, nausea, vomiting, pharyngitis (inflammation of the pharyngeal mucosa) may occur, the occurrence of which is associated with the toxic effect of the drug. At long-term treatment streptomycin sometimes develop deafness, impaired gait and coordination of movements.

For prevention toxic action streptomycin should be given large doses vitamins B 6 and B 1.

Serum and gamma globulins.

Serums animal or human blood, rich in antibodies, can be used for therapeutic and prophylactic purposes. Serums are usually a preparation obtained from the blood of animals, most often horses, which for this purpose are previously immunized for several months with microbes, or their toxins, or toxoids. Sera are obtained from special clinically healthy horses kept at vaccine and sera institutes, where sera are prepared. Depending on what animals are immunized with - microbes or toxins, antimicrobial and antitoxic sera are distinguished.

Serums are produced in a purified and concentrated form, which allows you to reduce the volume of administered serum and avoid a number of side effects.

Serums are used only after testing for sterility and safety in animal experiments ( Guinea pigs, white mice). Serum activity is determined by the content of antitoxic units (AU) or preventive (protective) units in 1 ml. Antimicrobial serum is dosed in milliliters.

In some diseases, human sera are also used. Most often, the serum of people who have recovered from this disease is used. Serums are used mainly for medicinal purposes, since they create only temporary and passive immunity. Sometimes sera are also administered for prophylactic purposes.

Serums are available in ampoules or vials. Each ampoule must have a label indicating the institute that produced the serum, the name of the drug, the batch number and state control number, the amount of serum in the ampoule, the number of antitoxic units in 1 ml, expiration date. Usually, a label taken from one of the ampoules of this series is pasted into the medical history. Simultaneous administration of sera of different series is undesirable.

Serums are stored in a dry, dark place at a temperature of 2 to 10°C. Instructions for its use must be included in the boxes with the drug.

By appearance Serums should be clear or slightly opalescent. The color of the sera is pale yellow or golden. Turbid sera, with sediment, with foreign inclusions (fibers, burns), with sediment or flakes that do not break when shaken, are not suitable for use.

Prior to administration, the serum is heated in a water bath or in water to 36-37 °. The end of the ampoule is wiped with sterile cotton wool moistened with alcohol, and cut with an emery knife, after which upper part the ampoules are again wiped with alcohol and broken off.

Serum is usually administered intramuscularly or intravenously, less often subcutaneously, always under medical supervision.

Serum with therapeutic purpose it is necessary to enter as early as possible from the onset of the disease, since the serum binds only freely circulating toxin and is not able to influence that part of the toxin that has already managed to enter into contact with the cells and tissues of the body.

Vaccines

Vaccine therapy is used for long-term, sluggish infectious diseases - brucellosis, tularemia, chronic dysentery. In recent years, vaccines have also been recommended for use in certain diseases treated with antibiotics (typhoid fever, acute dysentery), since in these cases post-infection immunity is sometimes not developed enough due to the short stay of pathogens in the body.

Therapeutic vaccines are made from killed microbes or individual parts of a microbial cell. Under the influence of the vaccine, the protective factors of the body are stimulated: the production of antibodies increases, the phagocytic activity of the cells of the reticuloendothelial system increases, metabolism improves, etc., at the same time, specific sensitization decreases. Vaccines are dosed by the number of microbial bodies (brucella vaccine) or in milliliters (dysenteric vaccine).

For therapeutic purposes, vaccines can be administered intramuscularly, subcutaneously and intradermally. During treatment, the dose of the vaccine is gradually increased.

The dose of the vaccine and the duration of its use depend on the route of administration and the type of disease. Vaccine administration techniques and dosages are described in more detail in the individual diseases. Contraindications to the use of the vaccine are severe lesions of the cardiovascular system, nephritis, hepatitis.

Conclusion.

Infectious disease control interventions can be effective and provide reliable results in the most short term only in the case of their planned and integrated implementation, that is, systematic implementation according to a pre-compiled plan, and not from case to case. Anti-epidemic measures should be built with the obligatory consideration of specific local conditions and characteristics of the mechanism for the transmission of pathogens of a given infectious disease, the degree of susceptibility of the human team, and many other factors. To this end, the main attention should be paid in each case to the link in the epidemic chain that is most accessible to our influence. So, with malaria, this is the destruction of pathogens (malaria plasmodia) in the body of a sick person with the help of therapeutic agents and the destruction of mosquito vectors; in case of food toxic infections - sanitary supervision and withdrawal from consumption of contaminated products; with rabies - the destruction of the source of infection, i.e. stray dogs and other animals; with poliomyelitis - universal vaccination of children, etc.

Bibliography.

1. I.G. Bulkin "Infectious diseases".

2. V.I. Pokrovsky "Prevention of infectious diseases"

3. N.R. Paleeva "Reference Nurse"

Ticket number 9

In a number of infectious diseases (typhoid fever, paratyphoid fever, dysentery, diphtheria), pathogens can be intensively isolated during the recovery period (convalescence).

Transfer mechanism

Of great importance in the transmission of infectious diseases is the fecal-oral transmission mechanism. In this case, pathogens are excreted from the body of people with feces, and infection occurs through the mouth with food and water contaminated with feces.

The food way of transmission of infectious diseases is one of the most frequent. Both pathogens of bacterial infectious diseases (typhoid fever, paratyphoid fever, cholera, dysentery, brucellosis, etc.) and some viral diseases (Botkin's disease, poliomyelitis, Bornholm's disease) are transmitted this way. At the same time, pathogens can get on food products in various ways. The role of dirty hands does not require explanation: infection can occur both from a sick person or a bacteria carrier, and from people around who do not follow the rules of personal hygiene. If their hands are contaminated with the faeces of a patient or a carrier containing pathogens, then during the processing of food, these persons can infect them. Intestinal infectious diseases, therefore, are not without reason called diseases of dirty hands.

A certain role in the spread of intestinal infectious diseases with a fecal-oral infection mechanism belongs to flies. Sitting on dirty bedpans, various sewage, flies pollute their paws and suck pathogenic bacteria into the intestinal tube, and then transfer and excrete them on food products and utensils. Microbes on the surface of the fly's body and in the intestine remain viable for 2-3 days. When eating contaminated food and using contaminated utensils, infection occurs. Therefore, the destruction of flies is not only a general hygienic measure, but also aims to prevent intestinal infectious diseases. The presence of flies in an infectious diseases hospital or department is unacceptable.

Close to the food is the water way of transmission of infectious diseases. Cholera, typhoid and paratyphoid, dysentery, tularemia, brucellosis, leptospirosis, etc. can be transmitted through water contaminated with feces. The transmission of pathogens occurs both when drinking contaminated water, and when washing products, as well as when bathing in it.

Transmission through the air occurs with infectious diseases localized mainly in the respiratory tract: measles, whooping cough, epidemic meningitis, influenza, smallpox, pneumonic plague, diphtheria, scarlet fever, etc. Most of them are carried with droplets of mucus - droplet infection. Pathogens transmitted in this way are usually unstable in the external environment and quickly die in it. Some microbes can also be transmitted with dust particles - dust infection. This route of transmission is possible only in infectious diseases, the pathogens of which are resistant to drying (anthrax, tularemia, tuberculosis, fever, smallpox, etc.).

In other cases, development or reproduction and accumulation of pathogens occurs in the body of insects (louse - with typhus and relapsing fever, flea - with plague, mosquito - with malaria). In such cases, insects are intermediate hosts, and the main reservoirs, i.e., sources of infection, are animals or a sick person. Finally, the pathogen can persist in the body of insects for a long time, being transmitted germinally through the laid eggs (transovarially). This is how the taiga encephalitis virus is transmitted from one generation of ticks to the next.

For some infections, soil is the route of transmission. For pathogens of intestinal infections, it is only a place for a more or less short stay, from where they can then penetrate into the sources of water supply; for spore-forming microbes - anthrax, tetanus and other wound infections - the soil is a place of long-term storage.

Classification of infectious diseases

1) Intestinal infections. The main source of infection is a sick person or a bacteriocarrier, who excrete huge amounts of pathogens with feces. In some intestinal infectious diseases, it is also possible to isolate the pathogen with vomit (cholera), with urine (typhoid fever).

Intestinal infectious diseases include typhoid fever, paratyphoid A and B, dysentery, amoebiasis.

2) Respiratory tract infections. The source of infection is a sick person or a carrier. The inflammatory process on the mucous membranes of the upper respiratory tract causes coughing and sneezing, which causes a massive release of the infectious agent with droplets of mucus into the surrounding air. The pathogen enters the body of a healthy person by inhalation of air containing infected droplets.

Respiratory tract infections include influenza, infectious mononucleosis, smallpox, epidemic meningitis, and most childhood infections.

3) blood infections. The causative agents of this group of diseases have the main localization in the blood and lymph. An infection from the blood of a sick person can enter the blood of a healthy person only with the help of blood-sucking carriers. A person with an infection of this group is practically not dangerous for others in the absence of a carrier. The exception is plague (pulmonary form), highly contagious to others.

The group of blood infections includes typhus and relapsing fever, tick-borne rickettsiosis, seasonal encephalitis, malaria, leishmaniasis and other diseases.

4) Infections of the outer integument. The infectious principle usually penetrates through damaged outer integuments.

These include sexually transmitted diseases; rabies and sodoku, infection with which occurs when bitten by sick animals; tetanus, the causative agent of which enters the body through a wound; anthrax, transmitted by direct contact from animals or through household items contaminated with spores; glanders and foot-and-mouth disease, in which infection occurs through the mucous membranes, etc.

Infection prevention

Preventing infections is just as important as controlling them. After all, even just washing your hands in time after visiting the restroom or upon coming from the street can save you from a number of intestinal infections. For example, the same typhoid fever. Of course, you can use disinfectants for "risk surfaces". But in any case, this does not give a 100% guarantee for a sufficiently long period. In addition, the prevention of infections can also be expressed in the fight against such dangerous carriers of infectious diseases as rodents and cockroaches. Why modern industry produces quite a lot of both effective and not very effective means.

Hateful ticks and mosquitoes can also become carriers of infections. Moreover, it can be both encephalitis and malaria, and AIDS, which is carried by mosquitoes along with the blood of its carrier. In order to get rid of mites, applied to the skin are widely used. special ointments and gels. And in order to get rid of mosquitoes, you can use widespread fumigators and even more advanced acoustic repellers.

Measures to combat infectious diseases can be effective and give reliable results in the shortest possible time only if they are planned and integrated, that is, systematically carried out according to a pre-planned plan, and not from case to case. Anti-epidemic measures should be built with the obligatory consideration of specific local conditions and characteristics of the mechanism for the transmission of pathogens of a given infectious disease, the degree of susceptibility of the human team, and many other factors. To this end, the main attention should be paid in each case to the link in the epidemic chain that is most accessible to our influence.

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Slides captions:

Major infectious diseases and their prevention

Educational questions Concept of infectious diseases Mechanism of transmission of infection Prevention of infectious diseases

The difference between infectious diseases and ordinary diseases They are caused by pathogens. Visible only with a microscope Transmitted from an infected organism to a healthy one Each contagious disease is caused by a specific microbe - the causative agent

Types of microorganisms that affect the human body Saprophytes are microorganisms that are harmless to humans. Once in the human body, they never cause diseases Opportunistic pathogenic microbes. Getting into the human body, for the time being they do not cause major changes. But if the human body is weakened, then these microbes quickly turn into pathogenic (pathogenic) microorganisms that are dangerous to health. Getting into the human body and overcoming its protective barriers, cause the development of an infectious disease

Group of infectious diseases a brief description of Infections included in the group Intestinal infections The causative agent is excreted in faeces or urine. Transmission factors are food, water, soil, flies, dirty hands, household items. Infection occurs through the mouth. Typhoid fever, paratyphoid A and B, dysentery, cholera, food toxic infections, etc. Respiratory tract infections, or airborne infections Transmission is carried out by airborne or airborne dust. Influenza, measles, diphtheria, scarlet fever, smallpox, etc. Blood infections The causative agent is transmitted through the bites of blood-sucking insects (mosquitoes, ticks, lice, mosquitoes, etc.) tick-borne encephalitis etc. Zoonotic infections Diseases transmitted through animal bites Rabies Contact-household diseases are transmitted by direct contact of a healthy person with a sick person, in which the infectious agent passes to a healthy organ. No transmission factor Infectious skin and venereal diseases, sexually transmitted (syphilis, gonorrhea, chlamydia, etc.)

Fecal-oral This way all intestinal infections are transmitted. The microbe with feces, vomit of the patient gets on food, water, dishes, and then through the mouth into the gastrointestinal tract of a healthy person. Liquid Characteristic for blood infections. Carriers of this group of diseases are blood-sucking insects: fleas, lice, ticks, mosquitoes, etc. Contact or contact-household Infection with the majority of sexually transmitted diseases occurs in this way when a healthy person is in close contact with a sick person. Zoonotic Carriers of zoonotic infections are wild and domestic animals. Infection occurs through bites or close contact with sick animals. Airborne This way all viral diseases of the upper respiratory tract spread. The virus with mucus, when sneezing or talking, enters the mucous membranes of the upper respiratory tract of a healthy person. The main ways of transmission of infection and their characteristics

Respiratory tract infections are airborne by drip The spread of droplets of mucus and saliva containing pathogens of infectious diseases when the patient coughs and sneezes.

Intestinal infections spread through food, water

Blood infections - through the bites of blood-sucking insects

Infection of the outer integument - the contact route.

Maintaining personal hygiene reduces the risk of disease

Preventive vaccinations are carried out

Isolate patients promptly

Conduct disinfection. Disinfection of the apartment and objects in it.

Answer the questions What are infectious diseases characterized by? What is the mechanism of transmission of respiratory infections? How important is personal hygiene? Prevention of infectious diseases.

Homework Draw up instructions for behavior in the spread of infectious diseases (epidemics)

Infectious diseases are an inexhaustible problem of more than one millennium and generation of people. Throughout history, every country has suffered from them to a greater or lesser extent. Once upon a time, this type of disease affected cities and towns on a large scale, not a single family was spared from grief and pain.

It is necessary to determine what diseases are called infectious? Under this general term, all pathologies caused by infectious microorganisms are hidden, which, after entering a living organism, begin to multiply and grow, thereby causing a pathogenic process inside it.

The pathogen is a foreign agent that is very quickly recognized by human cells. When they begin their fight with the "stranger" this leads to the appearance of painful symptoms, this is how the body's defenses manifest themselves.

Each of us has our own immune system. Someone strong, someone weakened, but it determines how far the infection process will go. Pathogens gradually affect the tissues of the body, its cells and reach the molecular elements, which in itself is dangerous. In this situation, there can be two initial options:

complete recovery;
death.

And in the case of the first, it is worth remembering that healing does not occur when the symptoms are muffled, but only after the pathogen is completely exterminated.

History of infectious diseases

Let's take a look at the past and find out how the history of infectious diseases was born.

With the advent of humanity and the animal world, an infectious conflict literally immediately occurred. When these two species came into contact, contagious diseases were formed that spread between other contacting people.

But even the most ancient inhabitants of the planet were not stupid and wanted to preserve their population, for which they developed preventive measures. In the 12th century BC, an epidemic of smallpox broke out among the Chinese people. In order to develop immunity to infection in healthy people, the so-called variolation was carried out - a kind of modern vaccination. To do this, scales of a skin rash were collected from a recovering person, dried, crushed, and allowed to be inhaled by uninfected individuals. To protect children, they put on dried clothes of the sick, on which secretions from smallpox were preserved. Even then, they assumed why infectious diseases are dangerous for humans and understood the way the infection was transmitted (not only through the air, but also through water and things). Therefore, all patients, as well as those who had the first signs of it, were immediately isolated.

Another correct conclusion was made by ancient people during the plague epidemic. They noticed that those who defeated the disease became immune to reinfection, so they were sent to care for the sick and bury the remains of those who died from a terrible disease.

Somewhat later, in his writings, Hippocrates characterized infectious diseases and the way they appeared. At first he assumed that the causative agents of infectious diseases are inanimate substances, but then he realized that infection of people and animals occurs through living contagions (as he called bacteria).

Avicenna was able to find a connection between smallpox, measles, leprosy and plague, which allowed him to declare the same nature of the origin of all infectious diseases. Bacteria he called small invisible living creatures wandering in the air and water.

By the middle of the 16th century, the Italian physician J. Frakostoro, on the basis of existing information, gave an accurate description of the causes of infectious diseases, classified the main infectious diseases, and revealed the question of the nature and ways of spreading the infection. Under detailed interpretation were:

If we talk about outstanding scientists, then:

L. Pasteur was remembered as a doctor who first introduced vaccination against chickenpox;
R. Koch discovered the microbacteria of tuberculosis disease (Koch's bacillus);
I. Mechnikov discovered and studied immunity at the cellular level and its main function;
S. Botkin described the clinic of viral hepatitis A (hence the name "Botkin's disease");
S.Prusiner discovered the prion species of infectious diseases.

The main features of infectious diseases are:

in the way they are transmitted to healthy people;
in specific features with which they manifest themselves (this is necessarily fever and fever);
in the rapid succession of symptoms, which complicates the diagnosis (within a few hours, a rash or indigestion may appear and then disappear, etc.);
in the premature disappearance of complaints. But at the same time, the infection can still persist, waiting for the right opportunity, when the defense is weakened, to hit even harder.

The classification of infectious diseases, which was proposed by L.V. Gromashevsky, divides them into 4 groups. In the human body can be:

All these types of infectious diseases are grouped according to the main feature - the location of the pathogen.

It is necessary to mention one more difference between infections, which distinguishes among them:

anthroponotic diseases (infection occurs from person to person);
zoonotic diseases (infection occurs from an animal to a person).

What are infectious diseases depending on the type of pathogen:

viral;
bacterial;
fungal;
protozoan;
prion.

Infectious diseases of people are classified according to one more criterion - according to the degree of contagiousness:

not contagious;
contagious;
highly contagious.

Unfortunately, economic development does not provide protection from similar diseases, and even in the richest countries, people continue to get infected. Of course, the destabilization of the socio-economic standard of living adversely affects people's health, which is why infectious diseases in Russia are increasingly affecting the population.

What infectious diseases are, you will learn a little later, and now we will talk in more detail on another topic.

Causes of infectious diseases

As mentioned earlier, the causes of infectious diseases lie in microorganisms that are pathological pathogens. When they get inside, a difficult biological process interactions between infection and human body which eventually leads to infection.

Interestingly, each pathology has its own certain kind pathogen. However, for example, sepsis has several pathogens at once, and streptococcus can cause both tonsillitis or scarlet fever, and erysipelas. In addition, every year there is a discovery of another previously unknown pathogenic agent.

There are 4 types of transmission routes for infectious diseases:

Alimentary:

Human infection occurs through food way. It can be unwashed or improperly prepared foods, dirty hands;
The infection enters the human body through contaminated water.

Airborne:

The causative agent can be in dust and penetrate through the respiratory tract;
A person is the source of infection, which spreads the virus through mucus secreted during coughing and sneezing.

Contact:

Directly contact way skin infections may spread;
Some infections multiply on the mucous membranes of the genital organs, and can be transmitted to all sexual partners of a person during sexual contact;
Sick people can leave their disease-causing microbes on household items, sharing which spreads them to healthy people.

Blood:

Infection occurs during a blood transfusion of an unhealthy person, when using non-sterile medical instruments for manipulation, if sterilization of instruments is neglected in hairdressing or tattoo parlors.
Transmission can occur in utero through the placenta of an infected mother or during childbirth;
Insects can be carriers of some infections. By biting people, they transmit the disease from one person to another.

Risk factors for infectious diseases:

We already know what the causes of infectious diseases are, but there is still a lot of interesting things ahead.

Children's infectious diseases

There are quite a lot of infectious diseases. Some more often affect men, others women, others the elderly, but today we will find out what infectious diseases are found in children.

The advantage of "childhood" diseases is that they are most often encountered once. After transferring the infection, the body develops a strong immunity to antibodies.

Among them are the following diseases:

Measles;
Rubella;
chickenpox (chickenpox);
Whooping cough;
Mumps (mumps).

Periods of development of infectious diseases

From the beginning of infection to recovery, several stages must pass. The following periods of an infectious disease are distinguished:

incubation period. Its beginning is facilitated by the penetration of a pathogenic agent into the body to a person. Duration can vary from a couple of hours to several years. Most often it is three weeks or less.
Pronormal period. It is determined when the first signs of the disease appear. At this stage, it is not always possible to establish accurate diagnosis due to the similarity of the clinical picture with other diseases;
Over the next two to four days there is an increase in the strength of the symptoms;
This is followed by a peak period, the intensity of which is determined by the type of pathogen. At this time, all symptoms specific to the disease will manifest themselves to the maximum;
On the decline in the severity of signs, we can talk about a period of extinction;
When the body fully recovers, there is a period of convalescence.

Symptoms of infectious diseases

Regardless of the causative agent of infectious diseases, the pathological process begins in approximately the same way. Usually these are general manifestations, which in the future may be replaced or supplemented by a more specific picture of symptoms. The onset of an infectious disease is preceded by the appearance of an infectious intoxication syndrome, which combines:

Treatment of infectious diseases

To be successful in therapy infectious pathologies their pathogenic nature needs to be influenced complex methods, combining drug method treatment with other wellness procedures.

The most powerful of the drugs have proven themselves antibacterial agents. However, it is worth remembering that the action of each type of antibiotic is directed to a specific pathogen. Self-medication here is simply unacceptable, because to identify its infectious nature, it is required to pass a series of tests.

As a supplement, immunoglobulins and antitoxic serum. They help the body fight the toxins that the “foreign agent” releases to poison it.

To prevent complications or consequences for a particular organ, use pathogenetic therapy. This includes:

Development of dietary nutrition;
Supplying the body with the missing vitamins;
Selection of anti-inflammatory drugs;
Choice medicines calming effect on the nervous system and cardiac activity.

Prevention of infectious diseases

Frequently Asked Question most people are the main infectious diseases, their classification and prevention. We discussed the first point earlier, but now it's time to talk about the activities that are carried out to avoid infections.

The first thing to do is limit contact with the sick. If you are infected, then try to isolate yourself from others so as not to be a spreader of the infection.
Immunoprophylaxis should be carried out in advance. This is especially true in autumn period to resilience defensive forces was the highest during cold weather. To do this, you need to eat a full and balanced diet, consume vitamins, both from vegetables and fruits, and from special pharmaceutical preparations, regularly remember about sports activity and personal hygiene.
Specific prevention of infectious diseases is vaccination. You can also drink a certain course of medications that prevent the possibility of infection. Antibiotics are not included in this group of drugs, they are used after infection for therapeutic purposes.

Infectious diseases

Problem modern medicine in that, along with improvements in technology, all infectious pathogens also adapt to the environment and become stronger. As evidence of this, we can cite the outbreak of an influenza epidemic this year, which claimed the lives of more than one hundred people. Despite the development of pharmacology, and various medical branches, there are deadly viruses that are invincible over nothing. However, recalling history, we can say that the current situation is not so deplorable, which means that progress is doing its job.

We bring to your attention the most common infectious diseases, the list of which is given below: