a biological phenomenon, the essence of which is the introduction and reproduction of microorganisms in a macroorganism with the subsequent development of various forms of their interaction from the carrier of pathogens to a pronounced disease.

Abortion infection (i. abortiva) - manifest I., characterized by a shortened acute period of the disease and the rapid disappearance of pathological phenomena.

Associated infection (i. associata) - see Infection mixed.

Autochthonous infection (nrk) - I., in which it develops in a macroorganism at the site of penetration and reproduction of the pathogen.

Generalized infection (i. generalisata) - I., in which the pathogens have spread mainly by the lymphohematogenous route throughout the macroorganism.

Dormant infection (i. cryptogena;.: I. cryptogenic, I. resting) - a form of manifestation of I., in which the pathogen is in an inactive state in separate foci (for example, in the palatine tonsils); manifests itself clinically only with a sharp weakening of the body's defenses.

Infection hardware (i. inapparens; In- + lat. appareo to be, to appear; synonym: I. asymptomatic, I. subclinical) - a form of manifestation of I., characterized by the absence of clinical signs, cleansing the body of the pathogen and the formation of immunity.

Intercurrent infection (i. intercurrens) - exogenous I., arising in a patient with another infectious disease and ending earlier than it, for example, with the flu of a patient with brucellosis.

Cryptogenic infection (i. cryptogena) - see Dormant Infection.

Latent infection (i. latens; syn.: I. mute, I. latent) - a form of I. manifestation, characterized by long-term preservation of the pathogen in the body without clinical manifestations that can occur during exposure (superinfection, cooling, etc.), causing weakening of the body.

Manifest infection (i. manifesta) - a form of manifestation And., characterized by clearly expressed clinical signs.

The infection is mute - see Infection is latent.

Focal infection (outdated; i. focalis; syn. I. focal) - I., in which the process is localized in a certain organ or tissue of the body; existence of I. about. denied, we can only talk about a local manifestation of the interaction of the pathogen with the macroorganism.

Cross infection (i. cruciata) - I. as a result of the mutual exchange of pathogens among persons (sick or convalescents) who are in close contact.

Resting infection - see Dormant infection.

Latent infection (i. latens) - see Infection latent.

Mixed infection (i. mixta; synonym: I. associated, I. combined) - I. with the participation of two or more different pathogens (more often viruses); manifested by the predominance clinical picture a disease caused by one of them, or an atypical, more severe course.

Combined infection (i. mixta) - see Mixed infection.

The infection is erased - the form of manifestation of I., characterized by a weak severity of clinical manifestations.

Subclinical infection (i. subclinicalis) - see Inapparent infection.

Focal infection (i. focalis - outdated) - see Focal infection.

Chronic infection (i. chronica) - a form of manifestation of I., characterized by a long course.

Exogenous infection (i. exogena) - I., in which pathogens are introduced from the outside, usually through environmental factors; the term covers all forms of I., except for autoinfection.

Experimental infection (i. experimentalis) - I., artificially reproduced in laboratory animals by dosed infection with known pathogens.

an integral part of a number of phrase-phrases (often in the plural), denoting groups of infectious diseases, distinguished by epidemiological or clinical signs, and sometimes a separate infectious; Such use of the term "infections is traditionally widespread, but raises objections, since the concepts denoted with its help in their essence represent one of the manifestations of I. as a biological phenomenon.

Hospital infections

Viral infections (i. virales) - infectious diseases caused by viruses.

Infections nosocomial (i. nosocomiales; synonym: I. hospital, I. in-hospital, I. hospital, I. nosocomial) -

1) infectious diseases that have joined the underlying disease or injury when the patient (victim) is in the hospital;

2) infectious diseases in medical workers arising from infection during the treatment or service of infectious patients.

In-hospital infections - see nosocomial infections.

Airborne infections - see Respiratory tract infections.

Herpetic infection (i. herpetica) - an infectious disease caused by viruses of the herpes group; I. g. include simple and shingles, chickenpox, cytomegaly, etc.

Hospital infections - see nosocomial infections.

Children's infections (i. infantum) - infectious diseases occurring mainly in children.

Respiratory tract infections (syn. I. airborne droplets) - infectious diseases, the causative agents of which are localized mainly in the mucous membranes of the respiratory tract, and infection occurs mainly through the airborne transmission mechanism; include sore throat, meningococcal infection, etc.

Quarantine infections (synonym I. conventional) - infectious diseases, which are subject to the International Health Regulations; include plague, cholera, smallpox, and yellow fever.

Intestinal infections - infectious diseases, the causative agents of which are localized mainly in the intestines, and infection occurs mainly through the fecal-oral transmission mechanism; include dysentery, cholera, etc.

koksaki infections - infectious diseases caused by enteroviruses from the Coxsackie group; include herpangina, epidemic pleurodynia, neonatal encephalomyocarditis, some viral diarrhea, etc.

Conventional infections - see Quarantine infections.

Blood infections - infectious diseases, the causative agents of which are localized mainly in the blood and lymph, and infection occurs mainly through the transmission mechanism of transmission; include relapsing fevers, tick-borne and mosquito fevers, etc.

Slow infections - little-studied infectious diseases of humans and animals caused by viruses, characterized by a long (sometimes long-term) incubation period, with persistence and accumulation of the pathogen in the macroorganism, a progressive long course, mainly with symptoms of a degenerative process in the central nervous system; to I. m. include, scrapie, (with intrauterine infection), etc.

Meningococcal infection (i. meningococciea) - an acute infectious disease caused by meningitidis with airborne transmission, characterized by damage to the nasopharynx (, carrier), as well as generalization in the form of meningococcemia or meningitis.

Outer cover infections - infectious diseases, infection with pathogens occurs mainly through the contact mechanism of transmission of infection; include, rabies, trachoma, etc.

Nosocomial infections (lat. nosocomialis hospital) - see nosocomial infections.

Especially dangerous infections - infectious diseases characterized by a very rapid spread, severe course, long-term subsequent disability or high mortality; include plague, cholera and smallpox.

Parainfluenza infection (i. paragripposa; syn.) - an infectious disease caused by any of the 4 types of parainfluenza virus of the family of paramyxoviruses transmitted by airborne droplets; proceeds with the phenomena of catarrhal inflammation of the respiratory tract (mainly laryngitis) and moderate intoxication.

Infection is a set of biological reactions with which a macroorganism responds to the introduction of a pathogen.

The range of manifestations of infections can be different. The extreme forms of manifestation of infections are:

1) bacterial carriage, persistence, live vaccination;

2) an infectious disease; there are clinical manifestations of infection, these reactions can be fatal.

The infectious process is the response of the collective of the population to the introduction and circulation of microbial agents in it.

Infectious diseases have a number of characteristic featuresdistinguishing them from other diseases:

1) infectious diseases have their pathogen - a microorganism;

2) infectious diseases are contagious, that is, they can be transmitted from patient to healthy;

3) infectious diseases leave behind more or less pronounced immunity, or increased sensitivity to this disease;

4) infectious diseases are characterized by a number of common features: fever, symptoms of general intoxication, lethargy, weakness;

5) infectious diseases have a clearly expressed staging, staging.

For the occurrence of an infectious disease, a combination of the following factors is necessary:

1) the presence of a microbial agent;

2) the susceptibility of the macroorganism;

3) the presence of an environment in which this interaction takes place.

A microbial agent is a pathogenic and opportunistic microorganism.

The infectious dose of the pathogen - the minimum number of microbial cells capable of causing an infectious process - is essential for the onset of an infectious disease. Infectious doses depend on the species of the pathogen, its virulence and the state of nonspecific and immune defense.

Tissues devoid of physiological protection against a specific type of microorganism serve as a place for its penetration into a macroorganism, or as an entrance gate for infection. The entrance gate determines the localization of the pathogen in the body, the pathogenetic and clinical features of the disease.

The external environment can influence both the macroorganism and the pathogenic microbes. These are natural and climatic, socio-economic, cultural and living conditions.

A number of infections are characterized by epidemics and pandemics.

An epidemic is a widespread infection in a population that covers large territories, characterized by the mass incidence of diseases.

Pandemic - the spread of infection to almost the entire territory of the world with a very high percentage of cases.

Endemic diseases (with natural focality) are diseases for which territorial areas with an increased incidence of this infection are noted.

Classification of infections

1. By etiology:

1) bacterial;

2) viral;

3) protozoal;

4) mycoses;

5) mixed infections.

2. By the number of pathogens:

1) monoinfection;

2) polyinfection.

3. By the severity of the course:

1) lungs;

2) heavy;

3) moderate.

4. By duration:

1) sharp;

2) subacute;

3) chronic;

4) latent.

5. By transmission routes:

1) horizontal:

a) airborne droplets;

b) fecal-oral;

c) contact;

d) transmission;

e) sexual;

2) vertical:

a) from mother to fetus (transplacental);

b) from mother to newborn in labor;

3) artifical (artificial) - during injections, examinations, operations, etc.

Depending on the localization of the pathogen, there are:

1) focal infection, in which microorganisms are localized in a local focus and do not spread throughout the body;

2) generalized infection, in which the pathogen spreads through the body by lymphogenous and hematogenous routes. In this case, bacteremia or viremia develops. The most severe form is sepsis.

There are also:

1) exogenous infections; arise as a result of human infection with pathogenic microorganisms coming from the environment with food, water, air, soil, secretions of a sick person, convalescent and micro-carrier;

2) endogenous infections; are caused by representatives of normal microflora - conditionally pathogenic microorganisms of the individual himself.

A variety of endogenous infections - autoinfections, they arise as a result of self-infection by transferring the pathogen from one biotope to another.

The following periods of infectious diseases are distinguished:

1) incubation; from the moment the pathogen enters the body until the first signs of the disease appear. Duration - from several hours to several weeks. The patient is not contagious;

2) prodromal; characterized by the appearance of the first unclear general symptoms. The pathogen multiplies intensively, colonizes tissue, begins to produce enzymes and toxins. Duration - from several hours to several days;

3) the height of the disease; characterized by the appearance of specific symptoms. The pathogen continues to multiply intensively, accumulate, release toxins and enzymes into the blood. There is a release of the pathogen from the body, so the patient is a danger to others. At the beginning of this period, specific antibodies are found in the blood;

4) outcome. There may be different options:

a) death;

b) recovery (clinical and microbiological). Clinical recovery: the symptoms of the disease have died away, but the pathogen is still in the body. This option is dangerous by the formation of a carrier and a relapse of the disease. Microbiological - complete recovery; c) chronic carriage.

Reinfection is a disease that occurs after an infection in the case of repeated infection with the same pathogen.

Superinfection occurs when, against the background of the course of one infectious disease, infection with another pathogen occurs.

Among bacteria, according to their ability to cause disease, there are:

1) pathogenic;

2) conditionally pathogenic;

Pathogenic species have the potential to cause infectious disease.

Pathogenicity is the ability of microorganisms, entering the body, to cause pathological changes in its tissues and organs. This is a qualitative species trait determined by pathogenicity genes - virulones. They can be localized in chromosomes, plasmids, transposons.

Conditionally pathogenic bacteria can cause an infectious disease when the body's defenses are reduced.

Saprophytic bacteria never cause disease, since they are not able to multiply in the tissues of the macroorganism.

The realization of pathogenicity comes through virulence - this is the ability of a microorganism to penetrate into a macroorganism, multiply in it and suppress its protective properties.

This is a strain trait, it is quantifiable. Virulence is a phenotypic manifestation of pathogenicity.

The quantitative characteristics of virulence are:

1) DLM (minimum lethal dose) is the number of bacteria, when introduced in the appropriate way into the organism of laboratory animals, 95–98% of the death of animals in the experiment is obtained;

2) LD 50 is the number of bacteria causing the death of 50% of animals in the experiment;

3) DCL ( lethal dose) causes 100% death of animals in the experiment.

Virulence factors include:

1) adhesion - the ability of bacteria to attach to epithelial cells. Adhesion factors are adhesion cilia, adhesive proteins, lipopolysaccharides in gram-negative bacteria, teichoic acids in gram-positive bacteria, in viruses - specific structures of a protein or polysaccharide nature;

2) colonization - the ability to multiply on the surface of cells, which leads to the accumulation of bacteria;

3) penetration - the ability to penetrate cells;

4) invasion - the ability to penetrate into the underlying tissues. This ability is associated with the production of enzymes such as hyaluronidase and neuraminidase;

5) aggression - the ability to resist the factors of non-specific and immune defense of the body.

The factors of aggression include:

1) substances of different nature, which are part of the surface structures of the cell: capsules, surface proteins, etc. Many of them suppress the migration of leukocytes, preventing phagocytosis;

2) enzymes - proteases, coagulase, fibrinolysin, lecithinase;

3) toxins, which are divided into exo- and endotoxins.

Exotoxins are highly toxic proteins. They are thermolabile, they are strong antigens, against which antibodies are produced in the body, which enter into toxin neutralization reactions. This trait is encoded by plasmids or prophage genes.

Endotoxins are complex complexes of a lipopolysaccharide nature. They are thermostable, weak antigens, and have a general toxic effect. Coded by chromosomal genes.

Infection(infectio - infection) - the process of penetration of a microorganism into a macroorganism and its reproduction in it.

Infectious process - the process of interaction between the microorganism and the human body.

The infectious process has various manifestations: from asymptomatic carriage to an infectious disease (with recovery or death).

Infectious disease - This is an extreme form of the infectious process.

An infectious disease is characterized by:

1) availability certain live pathogen ;

2) infectiousness , i.e. pathogens can be transmitted from a sick person to a healthy person, which leads to a wide spread of the disease;

3) the presence of a certain incubation period and characteristic sequential change periods during the course of the disease (incubation, prodromal, manifest (the height of the disease), recoolescence (recovery));

4) development clinical symptoms characteristic of this disease ;

5) availability immune response (more or less prolonged immunity after suffering a disease, development allergic reactions in the presence of a pathogen in the body, etc.)

The names of infectious diseases are formed from the name of the pathogen (species, genus, family) with the addition of the suffixes "oz" or "az" (salmonellosis, rickettsiosis, amebiasis, etc.).

Developmentinfectious process depends:

1) on the properties of the pathogen ;

2) from the state of the macroorganism ;

3) from environmental conditions , which can affect both the state of the pathogen and the state of the macroorganism.

Properties of pathogens.

The causative agents are viruses, bacteria, fungi, protozoa, helminths (their penetration - invasion).

Microorganisms that can cause infectious diseases are called pathogenic , i.e. disease-causing (pathos - suffering, genos - birth).

There are also opportunistic microorganisms that cause disease with a sharp decrease in local and general immunity.

Causative agents infectious diseases have properties pathogenicity and virulence .

Pathogenicity and virulence.

Pathogenicity Is the ability of microorganisms to penetrate into a macroorganism (infectivity), take root in the body, multiply and cause a complex of pathological changes (disorders) in organisms sensitive to them (pathogenicity is the ability to cause an infectious process). Pathogenicity is a specific, genetically determined trait or genotypic trait.

The degree of pathogenicity is determined by the concept virulence. Virulence is a quantification or pathogenicity. Virulence is phenotypic trait. This is a property of a strain, which manifests itself under certain conditions (with the variability of microorganisms, a change in the susceptibility of a macroorganism).

Quantitative indicators of virulence :

1) DLM (Dosis letalis minima) - minimum lethal dose - the minimum number of microbial cells that causes the death of 95% of susceptible animals under given specific experimental conditions (animal species, weight, age, method of infection, time of death).

2) LD 50 - the amount that causes the death of 50% of experimental animals.

Since virulence is a phenotypic trait, it changes under the influence of natural causes. It can also artificially change (increase or decrease). Enhancement carried out by repeated passage through the organism of susceptible animals. Decrease - as a result of exposure to adverse factors: a) high temperature; b) antimicrobial and disinfectant substances; c) growing on unfavorable nutrient media; d) the body's defenses - passing through the body of little susceptible or unresponsive animals. Microorganisms with weakened virulence are used to obtain live vaccines.

Pathogenic microorganisms also have specificity, organotropicity and toxicity.

Specificity - the ability to cause a certain infectious disease. Vibrio cholerae causes cholera, mycobacterium tuberculosis - tuberculosis, etc.

Organotropy - the ability to infect certain organs or tissues (the causative agent of dysentery is the mucous membrane of the large intestine, the influenza virus is the mucous membrane of the upper respiratory tract, the rabies virus is the nerve cells of the ammon's horn). There are microorganisms that can infect any tissue, any organ (staphylococci).

Toxicity - the ability to form toxic substances. Toxic and virulent properties are closely related.

Virulence factors.

Signs that determine pathogenicity and virulence are called virulence factors.These include certain morphological (the presence of certain structures - capsules, cell walls), physiological and biochemical signs (production of enzymes, metabolites, toxins that have an adverse effect on the macroorganism), etc. Pathogenic microorganisms can be distinguished from non-pathogenic microorganisms by the presence of virulence factors.

Virulence factors include:

1) adhesins (provide adhesion) -specific chemical groups on the surface of microbes, which, like a "key to a lock", correspond to receptors of sensitive cells and are responsible for the specific adhesion of the pathogen to the cells of the macroorganism;

2) capsule - protection against phagocytosis and antibodies; the bacteria surrounded by the capsule are more resistant to the action of the protective forces of the macroorganism and cause a more severe course of infection (pathogens of anthrax, plague, pneumococci);

3) surface-located substances of the capsule or cell wall of various nature (surface antigens): protein A of staphylococcus, protein M of streptococcus, Vi-antigen of typhoid bacilli, lipoproteins gram "-" bacteria; they perform the functions of suppressing immunity and nonspecific protective factors;

4) enzymes of aggression: proteasesdestroying antibodies; coagulasecoagulating blood plasma; fibrinolysindissolving fibrin clots; lecithinase, destroying lecetin membranes; collagenasethat destroys collagen; hyaluronidasethat destroys hyaluronic acid of the intercellular substance of the connective tissue; neuraminidase, destroying neuraminic acid. Hyaluronidase by breaking down hyaluronic acid, increases permeability mucous membranes and connective tissue;

toxins - microbial poisons - powerful factors of aggression.

Virulence factors provide:

1) adhesion - attachment or adhesion of microbial cells to the surface of sensitive cells of the macroorganism (to the surface of the epithelium);

2) colonization - reproduction on the surface of sensitive cells;

3) penetration - the ability of some pathogens to penetrate (penetrate) into cells - epithelial, leukocytes, lymphocytes (all viruses, some types of bacteria: Shigella, Escherichia); at the same time, cells die, and the integrity of the epithelial cover may be disrupted;

4) invasion - the ability to penetrate through mucous and connective tissue barriers into the underlying tissues (due to the production of enzymes hyaluronidase, neuraminidase);

5) aggression - the ability of pathogens to suppress nonspecific and immune defense of the host organism and cause the development of damage.

Toxins.

Toxins are poisons of microbial, plant or animal origin. They have a high molecular weight and produce antibodies.

Toxins are divided into 2 groups: endotoxins and exotoxins.

Exotoxinsstand out into the environment in the process of life of a microorganism. Endotoxinsfirmly associated with bacterial cell and stand out into the environment after cell death.

Properties of endo and exotoxins.

Exotoxins form pathogens of the so-called toxinemic infections, which include diftheria, tetanus, gas gangrene, botulism, some forms of staphylococcal and streptococcal infections.

Some bacteria simultaneously form both exo- and endotoxins (Escherichia coli, Vibrio cholerae).

Obtaining exotoxins.

1) growing toxigenic (exotoxin-forming) culture in a liquid nutrient medium;

2) filtration through bacterial filters (separation of exotoxin from bacterial cells); you can use other cleaning methods.

Exotoxins are then used to produce toxoids.

Getting toxoids.

1) 0.4% formalin is added to the exotoxin solution (the filtrate of the broth culture of toxigenic bacteria) and kept in a thermostat at 39-40C for 3-4 weeks; loss of toxicity occurs, but antigenic and immunogenic properties are retained;

2) a preservative and an adjuvant are added.

Toxoid Are molecular vaccines. They are used for specific prevention of toxinemic infections , and to obtain therapeutic and prophylactic antitoxic sera, also used for toxinemic infections.

Obtaining endotoxins.

Various methods are used destruction of microbial cells , and then purification is carried out, i.e. separation of endotoxin from other components of the cell.

Since endotoxins are lipopolysaccharides, they can be extracted from the microbial cell by destroying it with TCA (trichloroacetic acid) followed by dialysis to purify it from proteins.

The successes achieved in the fight against infectious diseases led to the fact that until recently, at the end of the 20th century, it seemed as if the epidemiology of infectious diseases had largely solved the main problems facing it. The impression was that infectious diseases had been defeated. But, despite the fact that in the Russian Federation, as in other economically developed countries, a significant decrease in the incidence of infectious diseases has been achieved, they continue to cause great damage to the health of people and the country's economy.

The role of infections as a cause of infant mortality and a factor of population disability is still significant; tuberculosis, poliomyelitis, brucellosis affect the musculoskeletal system; meningococcal infection, viral encephalitis can cause permanent damage to the central nervous system; toxoplasmosis, rubella in pregnant women lead to intrauterine fetal pathology.

In recent decades, the so-called endogenous infections have become of leading importance in infectious pathology. Caused by various pathogens (coccal forms, especially streptococci and staphylococci, Escherichia coli, Proteus, Pseudomonas aeruginosa, certain fungi, etc.) dermatitis, pustular skin lesions, nasopharyngitis, otitis media, conjunctivitis, colitis, appendicitis, bronchitis, bronchopneumoniae, cholismine cystitis diarrhea, as well as many forms of sepsis, are indirectly caused by factors of the technogenic environment and the way of life of modern mankind.

The problems of infectious pathology of the XXI century are: infections that we inherited from previous centuries (tuberculosis, malaria, leishmaniasis, syphilis, etc.) and to this it must be added that new, previously unknown "new infections" are being discovered, or rather newly diagnosed infections that have become known in recent decades (over 30): HIV infection, Lyme disease, legionellosis, ehrlichiosis, enterotoxigenic and enterohemorrhagic escherichiosis, viral fevers Lassa, Ebola, Marburg, human papillomavirus infection, etc., hepatitis E, C, D, F and G campylobacteriosis, hantavirus pulmonary syndrome.

The evolution of the infectious process is currently:

● an increase in the proportion of atypical, protracted and chronic forms of infectious diseases (resistance of the pathogen, changes in the reactivity of the macroorganism);

● more frequent development of mixed infections;

● superinfection;

● long-term persistence of the pathogen;

● updating opportunistic microflora;

● nosocomial (nosocomial) infections;

● an increase in the frequency of mycoses;

● the growing role of infection in different areas clinical medicine (surgery, gastroenterology, cardiology, urology, gynecology, etc.).

Thus, in the fight against infectious diseases, humanity has not achieved the goal of eliminating infections, but, on the contrary, the range of tasks facing humanity is constantly expanding. This is due not only to the dramatic changes in the socio-economic living conditions of the population that occurred in last years, urbanization, huge migration of people, pollution of the biosphere, etc., but also with an increase in infectious diseases, as well as with the expansion of the number of nosological forms of infections, deciphered recently thanks to scientific advances, as well as the rapid evolution of increasing pathogenicity and virulence of opportunistic pathogens.

Infection (from the Latin infectio - contamination, infection) - penetration of pathogens into the body and the emergence of a complex complex of processes of interaction between the body (macroorganism) and the pathogen (microorganism) under certain conditions of the external and social environment, including dynamically developing pathological, protective-adaptive, compensatory reactions (combined under the name "infectious process") ,

Infectious processis a complex of mutual adaptive reactions to the introduction and reproduction of a pathogenic microorganism in a macroorganism, aimed at restoring disturbed homeostasis and biological balance with the environment.

The modern definition of an infectious process includes the interaction of three main factors - the pathogen, the macroorganism and the environment, each of which can have a significant impact on its result.

The infectious process can manifest itself at all levels of the organization of the biological system (the human body) - submolecular, subcellular, cellular, tissue, organ, organismic and constitutes the essence of an infectious disease. An infectious disease itself is a particular manifestation of an infectious process, an extreme degree of its development. An example of a latent infectious process is the process resulting from vaccination.

Infectious diseases- a wide group of human diseases caused by pathogenic viruses, bacteria (including rickettsia and chlamydia) and protozoa. The essence of infectious diseases is that they develop as a result of the interaction of two independent biosystems - a macroorganism and a microorganism, each of which has its own biological activity.

Risk factors contributing to the development of infectious diseases:

Wars; social, economic disasters; ecological disturbances, natural disasters, catastrophes; hunger, poverty, begging, homelessness. Their main companions are a sharp decrease in defense systems, a weakening of the body, lice, typhus, plague, typhoid fever, etc.;

Moral, mental trauma, stress;

Severe long-term, debilitating diseases;

Poor living conditions, unbearable physical labor; insufficient, low-quality, irregular nutrition; hypothermia, overheating, accompanied by a sharp weakening of the body, especially its immune system;

Non-compliance, violation of the rules of personal hygiene;

Violation of the hygiene of the home, office space; poor living conditions, overcrowding;

Failure to seek medical attention or untimely, poor-quality medical care;

Drinking, as well as when washing low-quality water;

Eating food contaminated with infectious pathogens:

Refusal of vaccinations;

Alcoholism, drug addiction, promiscuous sex life.

Infectious diseases have a number of characteristics that distinguish them from noncommunicable diseases. These features include:

Contagiousness - the ability of the causative agent of an infectious disease to be transmitted from an infected organism to a healthy one. To characterize the degree of contagiousness, the index of contagiousness is determined, i.e. the percentage of cases of the total number of susceptible individuals at risk of infection. For example, measles is one of the highly contagious diseases in which the contagiousness index is 95-100%;

Specificity - each pathogenic microorganism causes a disease characterized by a certain localization of the process and the nature of the lesion;

Cyclicity - a change of periods of illness, strictly following each other: incubation period → prodromal period → height of the disease → convalescence;

Reactions of an infected organism to a microorganism - during the development of an infectious process, a macroorganism reacts as a whole, as a result of which systemic reactions of a whole organism (cardiovascular, nervous, digestive, endocrine, urinary systems, etc.) are detected in patients, and not only the reactions of the affected organ or system;

Formation of specific immunity - during the development of the infectious process, the formation of specific immunity occurs, the intensity and duration of which can vary from several months to several years and even decades. The completeness of the emerging specific immunity determines the cyclical nature of the infectious process. With weak immunity, it is possible to develop exacerbations and relapses of an infectious disease;

The condition necessary for the development of the infectious process is the presence of the microbe itself - the pathogen, the susceptible organism and certain environmental factors under which their interaction occurs. The causative agent must have certain qualitative and quantitative characteristics necessary for the occurrence of an infectious process. Qualitative characteristics include pathogenicity and virulence.

Pathogenicity (pathogenicity) is understood as a species multifactorial trait that characterizes the potential ability of a microbe to cause an infectious process. Despite the fact that pathogenicity is a genetically determined trait, it can change in different conditions.

The most important factors of pathogenicity are invasiveness and toxigenicity. Invasiveness is understood as the ability of the pathogen to penetrate through the skin and mucous membranes into the internal environment of the macroorganism, followed by possible spread to organs and tissues. Toxicity is the ability of microbes to produce toxins. To determine the degree of pathogenicity, such a concept as "virulence" is used, which is an individual feature of any pathogenic strain. Depending on the severity this feature all strains can be subdivided into high, moderate, weak, and avirulent. Quantitatively, the virulence of a strain of a microorganism can be expressed in lethal and infectious doses determined in experimental animals. The higher the virulence of the strain, the lower the infectious dose should be, which is the number of viable microbes that can cause the development of an infectious process in the host's body.

The main characteristics of a macroorganism that affect the development of the infectious process are resistance and susceptibility.

Resistance is understood as a state of resistance, which is determined by factors non-specific protection... Susceptibility is the ability of a macroorganism to respond to infection by the development of an infectious process. The human population is heterogeneous in terms of resistance and susceptibility to various microbes - pathogens. One and the same pathogen at the same infectious dose can cause different severity forms of the disease - from the mild to extremely severe and fulminant with a fatal outcome.

Epidemiological process is a set of successive cases of an infectious disease, the continuity and regularity of which is supported by the presence of a source of infection, transmission factors and the susceptibility of the population.

Thus, this process consists of three links:

1) the source of the infection;

2) the mechanism of transmission of pathogens of infectious diseases;

3) the susceptibility of the population.

Without these links, new cases of infection with infectious diseases cannot arise. The absence of any of the spreading factors leads to breaking the chain of the epidemic process and stopping the further spread of the corresponding diseases.

A prerequisite for the development of the epidemic process is the continuous interaction of its three constituent links:

1) the source of the infection;

2) the mechanism (s) of transmission of the pathogen;

3) a susceptible macroorganism.

The absence or elimination of any of these links leads to the elimination of the development of the epidemic process and to the cessation of the spread of an infectious disease.

The source of infection is an infected (sick or carrier) human or animal organism (an object that serves as a place of natural residence and reproduction of pathogens and from which the pathogen can in one way or another infect healthy people).

Sources of infection

A person is a sick person or a carrier (end of the incubation period; prodrome; height of the disease; convalescence, while the excretion of the pathogen continues) - anthroponosis. A sick person is contagious - at the end of the incubation period and the prodrome (intestinal infections, viral hepatitis, measles), at the height of the disease (almost all infections, however, the epidemiological danger in this period is less, since patients are usually in the hospital - hence the need for hospitalization or at least isolation infectious patients), in convalescence (while the excretion of the pathogen from the body continues, a control bacteriological examination is necessary). It is also possible to form a carrier - transient (a healthy person "passed" the pathogen through his body in transit, for example, with dysentery, salmonellosis - through the gastrointestinal tract without any reaction), convalescent (usually short-term - days, rarely weeks), chronic ( sometimes for life).

Animals (domestic, wild) - zoonosis. Animals - domestic and wild - can be sources of zoonoses - rabies, anthrax. A significant role is played by rats, which transmit about 20 infectious diseases, including plague, leptospirosis, sodoku, etc.

Saprozoonoses (causative agents of anthrax, leptospirosis, yersiniosis, etc.) are transitional forms, for which the features of both zoonoses and sapronoses are inherent.

Some pathogenic microbes can live in two reservoirs, which is characteristic of transitional forms. In these cases, such microbes should be classified according to the main (leading) reservoir.

The next link in the epidemic process is the transmission mechanism. The transmission mechanism is the way the pathogen moves from the source of the infection to the susceptible organism. For various infectious diseases, the transition of the pathogen from one organism to another occurs in completely different ways, since each pathogen has adapted to a certain, inherent transmission mechanism.

This mechanism consists of three phases, one after the other: release of the pathogen into the environment → presence of the pathogen on environmental objects → introduction of the pathogen into a susceptible organism.

The causative agents of infectious diseases are released into the environment with varying intensity depending on the stage, period of development of the disease and its form. In fact, the release of the pathogen can occur at any period of the disease and depends on the nature of the pathology and the emerging immune response.

It should be remembered that in many infectious diseases, the release of the pathogen can occur already at the end of the incubation period. Such isolation of the pathogen is quite dangerous for others, since the sick person does not yet have signs of the disease and, while maintaining his social activity, contributes to the wide spread of the pathogen. However, the most intense release of the pathogen into the environment occurs during the peak of the disease.

Bacteria carriers, which are clinically healthy people, emit infectious agents into the environment, are of exceptional epidemic importance as a source of infection.

In zoonoses, animals are the reservoir and source of infection, as mentioned above. Excretion of the pathogen also occurs through those organs and tissues in which the pathogen is predominantly located, however, the industrial and agricultural use of many animals contributes to the change and expansion of the possibilities of human infection (eating contaminated meat, milk, eggs, cheese, contact with infected wool, etc. ).

With sapronosis, pathogens are not isolated, since they autonomously live on abiotic objects in the environment and do not need the epidemic process as such.

The possibility and duration of the pathogen's stay in the environment are determined by its properties. For example, pathogens of measles, influenza and meningococcal infection cannot persist for a long time on objects of the external environment, since they die quickly enough (within a few minutes). The causative agents of shigellosis are able to persist in the environment for several days, while causative agents of botulism and anthrax persist in the soil for decades. It is this phase - the phase of the pathogen's stay on environmental objects - that should be used to carry out anti-epidemic measures in order to interrupt the epidemic process.

Direct entry or introduction of the pathogen into a susceptible organism can occur in various ways, which are divided into fecal-oral, aerogenic (respiratory), contact, blood (transmissible) and vertical. These transmission methods are the transmission mechanisms of the pathogen.

Characteristics of the mechanisms and routes of transmission of the causative agent for various infectious diseases

As a rule, the transmission (or transfer) of the pathogen from a sick organism to a healthy one is mediated by various elements of the external environment, which are called transmission factors. These include food products, water, soil, air, dust, care and environment items, arthropods, etc. Only in some cases is it possible to directly transmit the pathogen from a sick organism to a healthy one by direct contact. Specific elements of the external environment and (or) their combinations that provide the transfer of the pathogen under certain conditions are called the transmission path.

The last element of the epidemic process is the susceptible organism. The role of this element in the development of the infectious process is no less important than the previous two. In this case, both the individual susceptibility of a person and the collective can matter. In response to the introduction of an infectious agent, the body reacts with the formation of protective reactions aimed at limiting and completely freeing the body from the pathogen and also at restoring the impaired functions of the affected organs and systems.

The outcome of the interaction depends on a number of conditions:

● the state of local protection (intact skin, mucous membranes, the state of microflora);

● functioning of specific and nonspecific defense factors (state of immunity, production of protective substances);

● the number of penetrated microbes, the degree of their pathogenicity, the state of the nervous and endocrine systems person, age, food.

Thus, the decisive factor in the onset of the disease is the state of the human body, especially its immune system.

Immunity- a way of protecting the body from living bodies and substances that carry signs of genetically foreign information (including microorganisms, foreign cells, tissues or genetically altered own cells, including tumor cells).

The central organs of immunity are the thymus gland (thymus), the red bone marrow. Peripheral organs - spleen, lymph nodes, accumulations of lymphoid tissue in the intestine (Peyer's patches).

The functions of the immune system: recognition of foreign agents (foreign antigens) with the subsequent response, which consists in neutralizing, destroying and removing them from the human body

Types of immunity:

Congenital immunity - hereditarily fixed system of protection of multicellular organisms from pathogenic and non-pathogenic microorganisms, as well as endogenous products of tissue destruction.

Acquired immunity is a specific individual immunity, i.e. it is the immunity that exists specifically in certain individuals and to certain pathogens or agents.

Acquired is divided into natural and artificial, and each of them is divided into active and passive and, in turn, active is divided into sterile and non-sterile.

The acquired immunity for most infections is temporary, short-term, and for some of them it can be lifelong (measles, mumps, rubella, etc.). It is acquired naturally after an illness or as a result of immunoprophylaxis of a specific person and is caused by specific cellular and humoral factors (phagocytosis, antibodies) or cellular unresponsiveness only to a specific pathogen and toxin.

If immunity is acquired naturally in the course of life, it is called natural, if artificially, as a result of medical manipulations, then it is called artificial immunity. In turn, each of them is divided into active and passive. Active immunity is called because it is produced by the body itself as a result of the ingress of antigens, pathogens, etc. Natural active immunity is also called post-infectious and it is produced in the human body after pathogens enter, i.e. as a result of illness or infection.

Artificial active immunity is also called post-vaccination and it is developed after the administration of vaccines or toxoids.

Finally, active immunity, natural and artificial, are divided into sterile and non-sterile. If, after an illness, the body got rid of the pathogen, then the immunity is called sterile (measles, rubella, mumps, smallpox, diphtheria, etc.). If the pathogen does not die and it remains in the body, the immunity is called non-sterile. More often, this option is formed in chronic infections (tuberculosis, brucellosis, syphilis and some others). So, with tuberculosis, after infection, a Ghosn focus is often formed in the body and mycobacteria in the body can persist for life, creating non-sterile immunity. With the disappearance of the pathogen from the body, immunity also disappears after some time. Often, non-sterile immunity is observed with rickettsial and viral infections (typhus, herpes, adenovirus infection and etc.).

Active immunity is developed slowly within 2-8 weeks. According to the rate of development of the necessary intensity of immunity to the same antigen, people are heterogeneous, and this heterogeneity is expressed by the formulas and curves of the Gaussian normal distribution. All people can be divided into several groups according to the rate of development of sufficiently high immunity: from very fast production within 2 weeks to very slow - up to 8 weeks or more. Active immunity, although it is produced slowly, remains in the body for a long time. Depending on the type of infection, this immunity can persist for several months, within 1 year (cholera, plague, brucellosis, anthrax, etc.), several years (tularemia, smallpox, tuberculosis, diphtheria, tetanus, etc.) and even for life (measles , mumps, rubella, scarlet fever, etc.). Therefore, active artificial immunization is resorted to for planned specific immunization, regardless of the presence of diseases, according to the directive documents of the Ministry of Health and local authorities health care (orders, guidelines, instructions).

Passive immunity is called because antibodies in the body are not produced by themselves, but they are acquired by the body from the outside. With natural passive immunity, antibodies are transmitted to the child from the mother transplacentally or with milk, and with artificial immunity, antibodies are administered to people parenterally in the form of immune sera, plasma or immunoglobulins. Passive immunity in the body arises very quickly: from 2-3 to 24 hours, but does not last long - up to 2-8 weeks. The rate of onset of passive immunity depends on the way the antibodies are introduced into the body. If immune serum or immunoglobulin is injected into the blood, the body will rebuild in 2-4 hours. If antibodies are injected intramuscularly, then for resorption and their entry into the blood, it is necessary up to 6-8 hours, and if injected subcutaneously, then immunity will arise within 20-24 hours.

However, no matter how (intravenously, intramuscularly or subcutaneously) antibodies enter the body, passive immunity will arise in the body much faster than active immunity. Therefore, to artificial passive immunization must be resorted to for the treatment of diphtheria, tetanus, botulism, gas gangrene, anthrax and some other infections, with snake bites and other poisonous living beings, as well as for prophylaxis for epidemic indications: in case of the threat of infection (flu), contact in foci of anthrax , botulism, measles, flu and others, when bitten by animals for the prevention of rabies, for the emergency prevention of tetanus, gas gangrene and some other infections. Acquired (adaptive) immunity is formed during life under the influence of antigenic stimulation.

Congenital and acquired immunity are two interacting parts of the immune system that provide the development of an immune response to genetically foreign substances.

Factors influencing the development of the epidemic process

The social factors that affect the development of the epidemic process include: economic; sanitary and communal improvement; level of development of the health care system; nutritional features; working and living conditions; national and religious customs; wars; population migration; natural disasters. Social factors are of great importance for the development of the epidemic process; they can cause the spread of infectious diseases or, conversely, reduce the incidence.

Environmental factors (physical, chemical, biological) can also affect the development of the infectious process, but they play only an indirect role, influencing both the macroorganism and microbes. In particular, their effect on a macroorganism can lead to both an increase and a decrease in the resistance of the macroorganism, and the effect on microbes can be accompanied by an increase or decrease in their virulence. In addition, environmental factors can contribute to the activation and emergence of new mechanisms and ways of transmission of pathogens of infectious diseases, which is important in the epidemic process. In the end, the influence of environmental factors may be reflected in the level of infectious diseases in certain zones and regions.

The forms of interaction of living beings (microbial competition, opposition of microorganisms and protozoa, etc.) also have an influence on the course of the epidemic process.

Prevention of infectious diseases and measures to combat them

Measures for the prevention of infectious diseases can be roughly divided into two large groups - general and special.

1. General measures include state measures aimed at improving material well-being, improving medical support, working and resting conditions for the population, as well as sanitary and technical, agroforestry, hydraulic engineering and land reclamation measures, rational planning and development of settlements and much more, which contributes to the success of prevention and the elimination of infectious diseases.

2.Special are preventive measures carried out by specialists from medical and preventive and sanitary-epidemiological institutions. Along with health authorities, other ministries and departments, as well as the general population, are often involved in the implementation of these activities. For example, in the prevention of zoonotic diseases (glanders, foot and mouth disease, brucellosis, anthrax, etc.), agricultural management bodies, the veterinary service, and enterprises for the processing of leather raw materials and wool take part. The planning of preventive measures and control over their implementation is carried out by the health authorities. The system of preventive measures also includes international measures when it comes to especially dangerous (quarantine) infections.

The content and scale of preventive measures may vary depending on the characteristics of the infection, the affected contingent and the nature of the object. They can relate directly to the focus of infection or relate to an entire district, city, region. Success in organizing and carrying out preventive measures against infectious diseases depends on the thorough examination of the observed object.

For the development of the epidemic process, three main links are requiredev:

1.The source of the infection.

2. The mechanism of transmission of infection.

3. The receptive population.

The absence (or rupture) of any of them leads to the termination of the epidemic process.

When planning and carrying out preventive measures, theoretically and practically justified is their division into three groups:

1. Measures in relation to the source of infection, aimed at its neutralization (or elimination).

2. Measures in relation to the transmission mechanism, carried out with the aim of breaking the transmission paths.

3. Measures to increase the immunity of the population.

According to this epidemiological triad, three groups of preventive (anti-epidemic) measures are distinguished.

Impact on the first link of the epidemiological process - the source of infection

An essential role is played by preventive measures aimed at the source of infection, which in anthroponotic diseases is a person - a sick or excretory agent of the pathogen, and in zoonotic diseases - infected animals.

Anthroponoses. This group of preventive measures for anthroponosis includes diagnostic, isolation, treatment and regime-restrictive measures. Active and complete identification of patients is carried out on the basis of comprehensive diagnostics, including clinical, anamnestic, laboratory and instrumental research... With some infections (especially dangerous infections, typhoid fever, viral hepatitis B, etc.), hospitalization of identified patients is mandatory, with others (dysentery, escherichiosis, measles, chickenpox, etc.), in the absence of epidemiological and clinical contraindications, isolation of patients at home is allowed ...

The complex of regime measures includes, occupying an important place, disinfection of dishes, linen, premises and tools. Rational complex therapy hospitalized patients is also one of the preventive measures against infectious diseases.

Discharge of patients from the hospital is made after complete clinical recovery and after a period specified for each infection, excluding the possibility of infection. If the disease is characterized by a bacteriological carrier, then the discharge of convalescents is carried out only when negative results of bacteriological research are obtained.

Active identification of bacteria-excreting bacteria and their sanitation is one of the important preventive measures. The identification of bacteria-excretors is carried out in the focus of infection, among convalescents at discharge and in the long term after it, as well as among persons of decreed professions (catering department, waterworks, children's institutions). The identified bacteriological excretors are temporarily suspended from work, registered and routinely carried out bacteriological examination.

Restrictive measures. To prevent the further spread of infectious diseases that have arisen in the collective, restrictive measures are taken against persons who have been in contact with patients and are at risk of infection. Contact persons should be considered as a potential source of infection, as they may be infected and be in the incubation period or be excretory agents. The content of the restrictive measures depends on the nature of the infection, the professional affiliation of the contact persons, etc. They include medical supervision, separation and isolation.

Medical supervision is carried out for a period determined by the maximum duration of the incubation period for a given disease. It includes interviewing, examination, thermometry and laboratory examination of contact persons. Medical supervision allows you to identify the first symptoms of the disease and isolate patients in a timely manner.

Dissociation. Children attending institutions, or adults working in childcare facilities, and in some cases in food enterprises (for example, contacts for typhoid fever), are subject to separation, i.e. they are prohibited from visiting the institutions where they work for the period established by the instructions for each infectious disease.

Insulation. In case of especially dangerous infections (plague, cholera), all those in contact with patients are subject to isolation and medical supervision in an isolation ward. This event is called observation and is an integral part of the quarantine measures carried out for these diseases. The duration of isolation corresponds to the incubation period - with plague 6 days, with cholera - 5 days. In those historical times, when the incubation period was not yet known, the isolation of contact persons with plague and some other infections lasted 40 days, hence the name "quarantine" (Italian quarantena, qaranta giorni - 40 days).

Measures for the sanitary protection of the country's territory carried out by sanitary-epidemiological and specialized anti-epidemic institutions deployed in sea and river ports, airports, on highways and railways are also of great importance. The scope of measures and the procedure for their implementation are determined by the "Rules for the Sanitary Protection of the Territory" of our country, in the preparation of which the requirements of the "International Sanitary Rules" adopted by WHO are taken into account.

Infections of international importance are classified into two groups: diseases subject to regulation (plague, cholera, yellow fever and smallpox) and diseases subject to international surveillance (typhus and relapsing fever, influenza, polio, malaria). Member countries of WHO are obliged to inform this organization in a timely manner about all cases of diseases that are subject to health regulations, and about the anti-epidemic measures taken in connection with this.

Zoonoses. Preventive measures in relation to the source of infection in zoonoses have some peculiarities. If the source of infection is domestic animals, then sanitary and veterinary measures are taken to improve their health. In those cases when synanthropic animals - rodents (mice, rats) are the source of infection, deratization is carried out. In natural foci where the source of infection is wild animals, if necessary, their population is reduced by extermination to a safe level that prevents human infection.

Impact on the second link of the epidemiological process - the mechanism of transmission of the pathogen

In the prevention of infectious diseases, the impact on the transmission mechanism of the pathogen is an important measure. The transmission of an infectious principle from a patient to a healthy one occurs through the external environment using various factors (water, food, air, dust, soil, household items), which determines the variety of preventive measures.

Currently, all preventive measures aimed at the second link of the epidemic process are divided into three main groups:

1) sanitary and hygienic;

2) disinfection;

3) disinsection.

In intestinal infections with a fecal-oral mechanism of infection (typhoid fever, dysentery, cholera), food and water are the main factors in the transmission of the pathogen, less often flies, dirty hands, and household items. In the prevention of these infections, measures of general sanitary and hygienic plan, various methods of disinfection are of the greatest importance. General sanitary measures are communal and sanitary measures, food, school, industrial sanitary supervision, raising the level of general and sanitary hygienic culture of the population.

TO preventive measuresaffecting the path of transmission of the infectious principle also includes disinfection, which is carried out in the foci of infectious diseases, as well as in in public places (train stations, transport, hostels, public toilets) regardless of the presence of an outbreak or epidemic of an infectious disease.

With respiratory tract infections (measles, rubella, diphtheria, scarlet fever, meningococcal infection, influenza, etc.) compared with intestinal infections carrying out measures to suppress the pathways of transmission of the pathogen presents great difficulties. The transmission of these infections through the air is facilitated by microbial aerosols (droplets and nuclear phases) and infected dust, therefore, preventive measures are the sanitation of the indoor air and the use of respirators. As for disinfection, it is almost never used for those infections of the respiratory tract, the causative agents of which are unstable in the external environment (measles, chickenpox, rubella, mumps). Disinfection is carried out with scarlet fever and diphtheria.

Of great importance for the prevention of vector-borne infections are pest control agents aimed at destroying the vectors of pathogens - blood-sucking ticks and insects. Collective and individual protection measures are also applied against attack and vector bites.

Impact on the third link of the epidemiological process

Increasing the immunity of the population is carried out through the introduction of two directions of prevention - nonspecific and specific (immunoprophylaxis). Due to the systematic mass implementation of preventive vaccinations, the incidence of diphtheria, poliomyelitis, whooping cough, measles, mumps and other vaccine-dependent infections has decreased to a sporadic level. It is no less important to carry out preventive vaccinations according to epidemic indicators, especially with the aim of preventing rabies, tetanus, when immunization is the main means of preventing diseases.

Immunization (from Latin immunis - free, free from something) - a method of creating artificial immunity in humans and animals. Distinguish between active and passive immunization.

Active immunization consists in the introduction of antigens into the body. The most widespread form of active immunization is vaccination, i.e. the use of vaccines - preparations obtained from microorganisms (bacteria, rickettsia and viruses) or products of their vital activity (toxins) for the specific prevention of infectious diseases among humans and animals. Active immunization is carried out by applying a drug (for example, a vaccine) to the skin, by introducing it intradermally, subcutaneously, intramuscularly, intraperitoneally, intravenously, through the mouth, and by inhalation. Vaccination remains a promising and cost-effective area of \u200b\u200bprevention.

Characterization of vaccines

Types of vaccines

Live vaccines

They contain vaccine strains of pathogens of infectious diseases that have lost the ability to cause disease, but retained high immunogenic properties. Live vaccines are used for immunization against poliomyelitis, mumps, measles, tuberculosis, brucellosis, tularemia, anthrax, plague, typhus, yellow fever, Q fever, tick-borne encephalitis, rabies, chickenpox and other infections.

Inactivated vaccines

They are obtained by acting on pathogenic bacteria and viruses by physical (high temperature, ultraviolet light, gamma irradiation) and chemical factors (phenol, formalin, merthiolate, alcohol, etc.). Used for immunization against whooping cough, typhoid fever, cholera, poliomyelitis, rabies, tick-borne encephalitis and other infections.

Toxoid

Passive immunization is carried out by injecting serum or serum fractions of the blood of immune animals and humans subcutaneously, intramuscularly, and in urgent cases - intravenously. Such preparations contain ready-made antibodies that neutralize the toxin, inactivate the pathogen and prevent its spread.

Passive immunization creates short-term immunity (up to 1 month). Knei are used to prevent disease in case of contact with a source of infection in measles, diphtheria, tetanus, gas gangrene, plague, anthrax, influenza, etc. Seroprophylaxis or, if the disease has already developed, to facilitate its course, serotherapy.

Ministry of Health Order Russian Federation (Ministry of Health of Russia) dated March 21, 2014. No. 125ng. Moscow "On the approval national calendar preventive vaccinations and the calendar of preventive vaccinations for epidemic indications. "

Order of the Ministry of Health of Russia

No. 125n of 03/21/2014

ATTACHMENT 1

National vaccination calendar

EXAMPLE TEST PROBLEMS

Please provide one correct answer

1.The epidemic process is called:

a) the spread of infectious diseases among plants

b) the spread of pathogens among blood-sucking vectors

c) the spread of infectious diseases in the human population

d) the state of infection of the human or animal organism

2. The elimination of an infectious disease as a nosological form means:

a) absence of diseases

b) lack of conditions for the implementation of transmission mechanisms

c) lack of carriage

d) elimination of the pathogen as a biological species

e) lack of susceptible persons

3. Vaccines and toxoids are intended for:

a) emergency prevention of infectious diseases

b) developing active immunity to infectious diseases

c) serological diagnosis of infectious diseases

d) treatment of infectious diseases

SITUATIONAL PROBLEM

A 27-year-old patient, an employee of an oil refinery, asked for help on the fifth day of illness. Complaints: strong headache, dizziness, general weakness, lack of appetite, fever, nausea, vomiting, dark urine, discolored feces.

The disease began acutely with high temperature, headache, nausea and vomiting. She was treated independently for the flu, taking aspirin, arbidol. The condition worsened sharply, general weakness, headache, and vomiting increased several times. Summoned Ambulance - preliminary diagnosis of viral hepatitis.

Two months ago she underwent an operation to extract a tooth. 2 weeks rested in nature - drank water from the reservoir.

Objectively. Temperature 37.6 ° C. Intense yellowness of the skin, sclera and oral mucosa. On the skin of the upper chest, in the area of \u200b\u200bthe shoulders and forearms, single hemorrhagic rashes measuring 1 × 1 cm. I had nosebleeds twice. Heart sounds are muffled, the rhythm is correct. Pulse 106 beats. per minute of satisfactory qualities. Hell 90 / 60mmHg Lung vesicular breathing. The size of the liver - percussion, the lower border is determined by the midline at the level of the costal arch, its edge is sharply painful, the upper border is at the level of the 7th rib. The spleen is not palpable. Ortner's symptom is positive.

THE TASK

1.What epidemiological data should be obtained?

2.Possible route of infection?

3. What anti-epidemic measures should be taken in the outbreak?