Types of diseases and their prevention. Ministry of General and Vocational Education
Classification of infectious diseases
External signs of an infectious disease
The emergence and spread of infectious diseases
Prevention of infectious diseases
The most common infectious diseases
6.2. Infectious (epidemic) hepatitis - Botkin's disease.
6.3. Botulism.
6.4. Foodborne illnesses
6.5. Flu.
6.6. Diphtheria.
6.7. Rubella.
6.8. Scarlet fever.
6.9. Mumps (mumps).
Classification of microorganisms
The entire variety of microorganisms known to modern science from the point of view of their influence on the human body is divided into three types:
Saprophytes- microorganisms harmless to humans. When they enter the human body, they never cause diseases. People live with them peacefully and amicably.
Conditionally pathogenic microbes. Once in the internal environment of a person, they do not cause serious changes for the time being. But if the human body is weakened as a result of severe injury, long-term illness or other reasons, opportunistic microbes very quickly turn into health hazards.
Pathogenic (pathogenic) microorganisms. When pathogenic microbes enter the human body and overcome its protective barriers, they cause the development of an infectious disease. This always happens when the body does not have special protection - immunity.
Our country has adopted a classification of infectious diseases, which is based on the mechanism of transmission of the infectious principle and its localization in the body. According to this classification, all infectious diseases are divided into five groups:
Intestinal infections
Zoonotic infections
Contact and household infections (to the begining)
Classification of infectious diseases
| Infectious group diseases | a brief description of | Infections included in the group |
| Intestinal infections | The pathogen is excreted in feces or urine. Transmission factors include food, water, soil, flies, dirty hands, and household items. Infection occurs through the mouth | Typhoid fever, paratyphoid A and B, dysentery, cholera, food poisoning, etc. |
| Respiratory tract infections, or airborne infections | Transmission is carried out by airborne droplets or airborne dust. | Influenza, measles, diphtheria, scarlet fever, smallpox, etc. |
| Bloodborne infections or vector-borne infectious diseases | The pathogen is transmitted through the bites of blood-sucking insects (mosquitoes, ticks, lice, mosquitoes, etc.) | Typhus and relapsing fever, malaria, plague, tularemia, tick-borne encephalitis, etc. |
| Zoonotic infections | | Diseases transmitted through animal bites |
| Contact and household infections | Diseases are transmitted through direct contact between a healthy person and a sick person, in which the infectious agent passes to a healthy organ. No transfer factor | These are all infectious skin and venereal diseases that are sexually transmitted: syphilis, gonorrhea, chlamydia, etc. |
This or that infectious disease is associated with the penetration of a certain microorganism into the body. For example, the pertussis bacillus causes only whooping cough, the dysentery bacillus causes dysentery, the diphtheria bacillus causes diphtheria, and vibrio cholerae causes cholera. (to the begining)
External signs of an infectious disease
Most infectious diseases are accompanied by fever, chills, weakness throughout the body, and headache. Coughing, sneezing, profuse nasal discharge, sometimes vomiting, repeated loose stools, and pain in the abdominal area often appear. A distinctive feature of many infectious diseases is the appearance of a rash in the form of small reddish spots on the skin in various parts of the body. Sometimes a small bubble filled with clear liquid is visible in the center of the spot. As a rule, the diagnosis of an infectious disease is made on the basis of a bacteriological examination of the patient’s natural wastes (throat swab, genital secretions, skin scraping, rectal smear). External signs of an infectious disease do not appear immediately from the moment the pathogenic microbe enters the body, but only after some time. The time from the introduction of a microorganism to the manifestation of the disease is called the incubation period. The duration of the incubation period for each infectious disease is different: from several hours to several weeks and even years. The incubation, or latent, period does not mean that nothing happens in the body during this period. On the contrary, there is a fierce struggle between the pathogenic microbe and the body.In the development of an infectious disease, several successively changing periods are traced: latent (incubation) period, onset of the disease, active manifestation of the disease, recovery. The duration of the periods varies and depends on the nature of the infection. (to the begining)
The emergence and spread of infectious diseases
Infectious diseases differ from all others in that they spread quite quickly among people. The massive spread of an infectious disease, significantly exceeding the normal incidence rate, is called an epidemic. If it covers the territory of an entire state or several countries, it is called a pandemic.All infectious diseases are contagious and are transmitted from a sick person or sick animal to a healthy one. But a healthy person can also serve as a source of infectious disease. After an illness, for still unclear reasons, a paradoxical situation arises. The person recovers and feels well, but the pathogenic microbe continues to be present in his body. An amazing union arises when one organism does not notice the other. This can go on for as long as you like. This is not dangerous for the body itself, but it is extremely dangerous for others, since the pathogenic microbe remains unharmed for a long time and is released into the external environment. This phenomenon is called bacilli carriage, and humans are called bacilli carriers
At least five routes of transmission are currently known:
fecal-oral route all intestinal infections are transmitted (“diseases of dirty hands”); a pathogenic microbe with feces, vomit of a sick person or a carrier of the bacilli gets onto food, water, dishes, and then through the mouth enters the gastrointestinal tract of a healthy person, causing disease (this is how, in particular, the spread of dysentery occurs);
by airborne droplets all viral diseases of the upper respiratory tract spread, primarily influenza: the virus with mucus, when sneezing or talking, enters the mucous membranes of the upper respiratory tract of a healthy person, who becomes infected and falls ill;
liquid path transmission is typical for so-called blood infections; The carriers of this group of diseases are blood-sucking insects: fleas, lice, ticks, mosquitoes (this is how plague and typhus are transmitted);
carriers of zoonotic infections wild and domestic animals serve; infection occurs through bites or through close contact with a sick animal (a typical representative of such diseases is rabies);
contact or contact-household way Most sexually transmitted diseases are contracted through close contact between a healthy person and a sick person (fungal diseases on the skin and nails are also transmitted through household contact). (to the begining)
Prevention of infectious diseases
To prevent the spread of infectious diseases, it is necessary to break the links connecting the elements of the general epidemiological chain and simultaneously influence each of its elements.First element- a sick person or animal. If an infectious disease is suspected, a sick person is isolated and treated. A sick animal is treated differently: if it is an animal valuable to humans, it is treated, in all other cases it is euthanized. The situation is more complicated with bacilli carriers. These are completely healthy people who would never even think of going to the doctor. Therefore, bacteria carriers must be actively identified. It is almost impossible to screen all people for bacillary carriage. Therefore, the survey is carried out selectively. It is subjected to those groups of people who are employed in catering units (buffets, canteens, restaurants) and in child care institutions.
Second element epidemiological chain - mechanisms of its transmission. To prevent the spread of infection, it is necessary to put a barrier on the routes of its transmission and destroy the mechanisms of its spread. To do this, you must follow the following rules in everyday life:
all food products must be subjected to heat treatment; plates, cups, forks, knives must be washed using household chemicals, then rinsed with copious amounts of water; fruits and vegetables must be thoroughly washed in running water; We must not forget about washing our hands before eating and after using the toilet;
for colds, a simple and reliable way to prevent the disease is a regular three-layer gauze bandage, which can be used both at work and at home; Individual dishes must be allocated for the patient and washed using disinfectants; the patient's handkerchiefs should be boiled and ironed well;
an effective way to prevent the spread of blood infections is to destroy or repel insects,
Zoonotic infections need to be prevented in several ways; valuable animals bred by state fur farms must regularly undergo veterinary control; identified sick animals must be treated; with a significant increase in the number of carriers and keepers of many infectious zoonotic diseases (and these are rodents: mice, rats, etc.), they are deratized (destructed)
the reduction of diseases transmitted through contact in everyday life can be achieved by increasing the hygienic culture of people, strengthening morality and ethics, stimulating public intolerance towards all manifestations of anticulture, violation of ethical norms and rules (an important element in this process is the education and upbringing of children and adolescents, instilling in them a culture health and healthy lifestyle).
Good nutrition, reasonable physical activity, and a healthy lifestyle also reduce the risk and likelihood of disease. In all cases of the occurrence of an infectious disease in a team, a system of measures aimed at preventing the spread of the disease, the so-called quarantine, is mandatory. In a simplified form, this is a strict restriction of movement and contacts of people among whom the disease was detected. The duration of quarantine depends on the latent (incubation) period of the identified disease and is calculated from the moment of isolation of the last patient (the incubation period for cholera is 5 days, for dysentery - 7 days, for typhus - 21 days, etc.). (to the begining)
The most common infectious diseases
Dysentery.The causative agent of the disease- dysentery bacillus.
While in the human body, the rod in the process of vital activity releases a very strong toxic substance (exotoxin). In the external environment, the stick is unstable. High and low temperatures, sunlight, and disinfectants are harmful to it. However, in feces, in linen, in moist soil, in milk, on the surface of fruits, berries, vegetables, paper and metal money, the dysentery bacillus retains its pathogenic properties for a long time. At the same time, a temperature of 60 °C and a 1% solution of carbolic acid kills it in 25-30 minutes.
Sources of dysentery- sick people or carriers of bacteria. Infection occurs through dirty hands, contaminated objects and food. Flies are carriers of dysentery. The disease is recorded throughout the year, at its peak. falls on July-August, the hottest months of summer.
Entering the intestines through the mouth, the dysentery bacillus, having successfully overcome the acidic barrier of the stomach, settles in the large intestine. In the process of life, it releases a toxin that causes general poisoning of the body. The activity of the nervous and cardiovascular systems, metabolism, water-salt, protein, carbohydrate, fat and vitamin balances are disrupted. The incubation period for dysentery ranges from 2 to 6 days.
Signs of dysentery.At the beginning of the disease, a person experiences general symptoms. Then the temperature rises to 38°C and higher, pain appears in the lower abdomen, loose stools mixed with blood. False urges are also typical for this disease, when there is nothing in the large intestine, but the urge to stool persists. The patient's tongue is covered with a white coating. After an illness, a weak and short-lived immunity is formed. Therefore, you can get dysentery several times during the year.
Prevention of dysentery consists of strict adherence to the rules of personal hygiene, food hygiene and timely identification of bacilli carriers.
(to the begining)
Infectious (epidemic) hepatitis - Botkin's disease.
The causative agent of Botkin's disease- a special type of filterable virus. It primarily affects the liver and is found in the blood, bile and feces of a sick person. The virus tolerates the external environment well and is therefore very dangerous.
Infection of a healthy person can occur in two ways: through the gastrointestinal tract (the virus enters there with water and food), and also through the blood (using a poorly sterilized syringe, transfusion of uncontrolled blood during surgery).
The incubation period for intestinal infection lasts up to 50 days, and for infection through blood - up to 200 days.
Signs of Botkin's disease The disease begins with general signs of intoxication. A person develops fatigue, fatigue, headache, increased excitability, often loss of appetite, a feeling of pressure in the pit of the stomach (in the right hypochondrium), nausea, repeated vomiting, and heartburn. Sometimes there is pain in large joints. After one or two days, a change in skin color occurs: it becomes dark and spotty. The liver enlarges, the person feels heaviness in the right hypochondrium. Then comes the so-called icteric period. Itchy skin appears. The eyes are initially covered with a slight yellowness, then the yellowness intensifies. The skin turns yellow from canary to saffron. The color of the stool changes: it becomes white, reminiscent of white clay. This occurs on the 8-11th day of the onset of the disease. On the 18-22nd day, the signs of the disease weaken and recovery begins.
Treatment carried out in a hospital. The patient is prescribed a strict diet, liquid food without fat, dairy products, cottage cheese, and sweet dishes are recommended. After the disease, it is necessary to strictly follow a diet for about a year. The consumption of any alcoholic beverages is strictly prohibited.
A healthy person who has had Botkin's disease poses a danger, since the virus remains in his blood even after recovery. Transfusion of blood from such a person to a healthy person leads to illness.
The main means of prevention- mandatory compliance with personal hygiene and food hygiene requirements. (to the begining)
Botulism.
The causative agent of the disease serves as a spore-bearing rod, which has several varieties. It has exceptionally high stability in the external environment. Kills at 120°C (pressure sterilization
1 atm.), 20% formalin solution and 5% phenol solution kill the bacillus after 24 hours. The botulism bacillus grows and develops in the complete absence of oxygen.
Source of infection Usually there are herbivores. Transmission of infection occurs through food products: smoked and salted meat, canned meat, fish and vegetables (especially homemade).
Once in a favorable environment, the rod multiplies intensively at a temperature of about 37°C, releasing a highly toxic substance (350 times stronger than the venom of a rattlesnake).
The greatest destruction during botulism is observed in brain cells; changes also occur in the central nervous system.
Incubation period lasts from 1 hour to two days, but on average it lasts 10-12 hours.
Signs of botulism. The disease begins acutely: headache, general malaise, weakness, abdominal pain, colic, repeated vomiting, and a distended abdomen. The temperature rises slightly. If treatment is not started, after one or two days dizziness increases, visual disturbances occur (everything is seen as if in a fog, double vision, the pupils are dilated, often in the water eye, strabismus occurs), speech becomes slurred, swallowing is impaired, and the person feels thirsty. The total duration of the disease ranges from 4 to 15 days. Often the disease ends in the death of the patient.
Giving help consists of very quickly washing the stomach with a warm 5% solution of baking soda (1 teaspoon per glass of water). It is necessary to administer serum and toxoid.
Prevention associated with the implementation of the necessary hygienic rules: eat fresh, well-washed fruits, berries, vegetables and good-quality canned foods.
It must be remembered that when canning at home, botulism poison appears most quickly in canned meat, cauliflower, green peas, then in eggplants and squash caviar, and lastly in all types of pickles. Therefore, when canning at home, the strictest hygiene requirements are necessary. (to the begining)
Foodborne illnesses
Foodborne illnesses are typical intestinal infections. They are caused by a group of microbes: staphylococci, streptococci, salmonella. All of them emit strong toxic substances that enter the blood and spread throughout the body.Sources of infections Usually there are sick people and bacteria carriers, as well as mouse-like rodents, geese, and ducks. The pathogen is transmitted through food products: meat, eggs, milk, dairy products. The incubation period lasts from 6 hours to two days. The peculiarity of foodborne illness is that several people often become ill at the same time.
Signs of infection. The onset of the disease is acute. After a few hours, but no later than a day, a person develops chills, the temperature rises to 38-39°C, he feels aches throughout the body, weakness, malaise, heaviness in the epigastric region and in the abdomen, sometimes cramping pain, nausea, Repeated vomiting begins, and a little later diarrhea, frequent urges, and copious liquid bowel movements with an unpleasant odor appear. All these signs indicate damage to the mucous membrane of the stomach and intestines. In addition to them, the cardiovascular system is affected. The pulse becomes rapid and weak, blood pressure drops, and a coma may occur.
Helping a sick person consists of completely removing food by repeatedly washing the stomach with warm boiled water, taking activated charcoal and a weak (2-4%) solution of bicarbonate of soda. Drinking plenty of fluids and a strict diet are advisable. In severe cases, the patient is hospitalized. To prevent diseases, strict adherence to food preparation rules and proper use of meat and meat products is necessary.
(to the begining)
Flu.
Infectious agents There is a whole variety of filterable viruses. The disease is recorded at all times of the year. Epidemics often occur that cause illness in hundreds and thousands of people. Viruses are unstable in the external environment; they quickly die under the influence of sunlight and conventional disinfectants.
Source of the disease- a sick man. Infection occurs through airborne droplets when coughing, sneezing, or talking. The duration of the incubation period ranges from several hours to two days.
Signs of the flu. The disease begins with the appearance of chills, malaise, weakness, headache, aches throughout the body. Redness of the mucous membrane and copious discharge of mucus from the nose and cough can often be observed. The temperature of the tour increases slightly. The disease ends in 5-6 days. It is extremely dangerous due to complications that can appear in any organs and systems (often these are disorders of the nervous system, cardiac activity, inflammation of the lungs, middle and inner ear).
Helping the sick. A flu patient should be isolated. In the room where it is located, wet cleaning is carried out using a clarified solution (0.5%) of bleach, a solution of chloramine (0.2%), a solution of hydrogen peroxide (2%), and detergent (0.5%).
Important preventive measures- vaccinations, administration of gammaglobulin and the use of dibazol, which has an immunostimulating effect. A good effect is achieved by using rimantadine according to the regimen indicated in the annotation for the drug. (to the begining)
Diphtheria.
The causative agent of the disease serves as a stick that is highly resistant in the external environment and releases a very strong toxic substance.
Sources of the disease are a sick person or a carrier of the bacteria. Infection most often occurs through airborne droplets from sneezing and talking, but infection through books, toys, and food is also possible. Children usually get sick. The entry gate of the pathogen is the mucous membrane of the nose, pharynx, eyes, damaged skin.
Incubation period lasts from 2 to 7 days. Depending on the location, diphtheria is distinguished in the pharynx, throat, nose, eye, ear, skin and even the external genitalia. If wounded, diphtheria of wounds is possible.
Signs of diphtheria. The disease begins acutely. With diphtheria of the pharynx, the patient develops general malaise. pain when swallowing, often vomiting. A grayish-white plaque forms, closely associated with the underlying tissue. The toxic substance is absorbed into the blood and spreads throughout the body, causing general poisoning. The temperature can rise to 38-39 °C; headache and weakness are felt. In severe cases, pain and swelling in the throat are observed. Diphtheria croup develops. It grows gradually. Initially, a slight cough appears, the temperature reaches 38 ° C. After two days, the cough intensifies, acquires a barking character, breathing is difficult, the voice shrinks, becomes hoarse, after a few days there is a complete absence of voice, difficulty breathing increases, leading to attacks of suffocation. The patient does not have enough air, he lies with his head thrown back (forced position), and there is an expression of fear on his face. This is a very dangerous condition that can lead to death. Therefore, an urgent visit to an infectious disease doctor is necessary. As a rule, in this case, the patient is administered diphtheria serum (ready-made antibodies) and antibiotics. In addition to serum, you can use steam treatment or cold moist air and agents that calm the nervous system. The disease is dangerous due to complications on the heart and nervous system.
Prevention of diphtheria consists primarily of immunization of children, revaccination of adults and identification of bacilli carriers. In case of an outbreak of diphtheria, quarantine is organized for 7 days from the moment of the last illness. During these days, the body temperature of those in contact with the patient is monitored and their condition is carefully monitored. The premises are disinfected, dishes and children's toys are treated with a disinfectant solution and boiling water. (to the begining)
Rubella.
The causative agent of infection- a filterable virus similar to measles.
Source of infection- a sick man. The route of transmission is airborne. Infection occurs through close contact with a sick person.
Signs of rubella. The incubation period lasts 2-3 weeks. The disease begins with a runny nose. cough. conjunctivitis. The temperature can rise to 38 °C. There is swelling and tenderness of the peripheral lymph nodes in the back of the head and behind the ears. This stage is very short. After 1-2 days, a rash appears on the face, then on the neck, and every other day on the torso and limbs. The rash consists of round or oval-shaped copper-pink non-merging spots, surrounded by a pale halo. In the center of the spot there is a small bubble filled with liquid. After a few days, the signs of the disease disappear.
Helping the sick. Treatment consists of 2-3 days of bed rest and good care. For preventive purposes, the patient is isolated for 10 days.
Rubella is very dangerous for pregnant women, especially in the first months of pregnancy. In case of illness, pregnancy is terminated due to the threat of deformities in the newborn. (to the begining)
Scarlet fever.
The causative agent of the disease- hemolytic streptococcus. The microbe secretes a very strong toxic substance, which has a general destructive effect on the body and determines the course of the disease. It is very stable in the external environment and can retain its pathogenic properties for many years. A person who has recovered from scarlet fever remains immune for life.
The disease is transmitted from a sick person or carrier of the bacilli to a healthy person by airborne droplets. Infection can occur indirectly: through food, clothes, toys, books, underwear and other objects. The entry point for infection is usually the pharynx (tonsils). There are known cases of scarlet fever joining wounds as a secondary infection.
Signs of scarlet fever. The disease begins suddenly. A headache appears, the body temperature rises to 39-40 ° C, pain in the mountains occurs, intensifying when swallowing, the mucous membrane in the pharynx becomes bright red, the tongue swells and becomes covered with a whitish-gray coating, yellowish-whitish films are visible on the tonsils. Lymph nodes in the neck become enlarged and painful. After 1-3 days, sometimes after 4-6 days, a scarlet fever rash appears - spots the size of a pinhead protruding above the skin. They are scattered in the groin, chest, stomach, back and inner thighs. Scarlet fever is dangerous due to complications in the heart, middle ear, kidneys, and lymph nodes. The patient is contagious to others throughout the entire period of illness and for another 5 days after all signs of the disease have disappeared.
Helping the sick. For treatment, antibiotics are used that have a pronounced effect on hemolytic streptococcus.
Prevention consists of isolating the patient and active immunization.
(to the begining)
Mumps (mumps).
The virus is filtered through all biological membranes. Mumps most often occurs in the winter season. After recovery, immunity lasts for life.
Source of infection- a sick person or a carrier of the bacteria.
Infection occurs by airborne droplets through close contact with a sick person. Susceptibility to the disease is very high at school age, in children from 1 to 4 years old it is relative, infants rarely get mumps. The patient is dangerous to others already 1-2 days before the appearance of a tumor of the salivary glands and before it disappears.
Signs of the disease. The latent period of the disease begins with general malaise, weakness, and headache. This lasts 1-2 days. Then a tumor of the parotid salivary gland appears, usually on one side. The tumor is visible in front of the ear and just below it. It is painful to the touch. The patient has difficulty chewing. Within 2-3 days the tumor increases. The temperature can reach 39-40 °C and then decreases relatively quickly within 3-4 days. The disease has a total duration of 3 to 7 days and proceeds favorably. However, its danger lies in the possibility of various complications. In sick children, inflammation of the meninges (meningitis) and inflammation of the pancreas (pancreatitis) often occur. The main danger of mumps is for boys. It is expressed in the fact that the complication often manifests itself in inflammation of the testicles. With bilateral damage (left and right testicle), this leads to infertility.
Helping the sick. During treatment, patients are isolated for 20 days, provided with bed rest, and rinsed with a 2% soda solution. (to the begining)
Infectious diseases are a whole group of illnesses, the etiological factor of which is pathogenic microorganisms - bacteria, viruses, prions. Once in the body, they begin to multiply intensively and produce toxins. A typical clinical picture of the disease develops.
One of the key properties of infectious diseases is contagiousness, that is, the ability of a pathogen to pass from a sick person or carrier to a healthy one. Therefore, preventive measures are mandatory.
Prevention is a set of measures aimed at stopping the spread of pathogenic microorganisms and preventing the development of diseases. There are primary and secondary prevention.
Primary prevention is a set of measures that influence the occurrence and spread of pathogens. Simply put, its goal is to prevent the occurrence of pathology.
Secondary prevention of infectious diseases is carried out after certain symptoms appear. Its goal is to eliminate risk factors that contribute to relapse of the disease, as well as to prevent complications.
Depending on the method and mechanism of influence on the cause of the disease, specific and nonspecific prevention are distinguished.
Specific prevention is the most effective means of combating infectious diseases. Its essence is the creation of immunity. There are three types of such prevention:
– active;
– passive;
– active-passive.
Active prevention consists of administering vaccines. They contain live or killed microorganisms or parts thereof. The immune system produces antibodies to them, which circulate in the blood for a long time. When infected, they neutralize the pathogen. It takes 3-4 weeks to develop immunity to most microorganisms.
During passive prophylaxis, ready-made antibodies are introduced into the body in the form of serum. This is usually done during epidemics, when there is no time to wait for the production of one’s own antibodies.
Active-passive prevention combines both previous types. The patient is given the vaccine and serum. The fact is that the lifespan of ready-made antibodies is short - only 2-3 weeks. But this time is enough for immunity to begin to form.
Nonspecific prevention is a set of actions that affect the spread of a pathogenic agent. These are general measures that include:
– hand washing;
– ventilation of premises;
– avoiding crowded places;
– use of personal protective measures, for example, masks and gloves when caring for the patient;
– increasing the overall resistance of the body:
– physical education classes;
– hardening;
– compliance with the work and rest regime.
Nonspecific prevention also includes quarantine - a set of measures that limit the contact of a sick person or a possible carrier with a healthy population. It provides for the isolation of patients and contacts, examination of those arriving from disadvantaged regions, disinfection of premises, cargo, and transport. This is the so-called health quarantine.
Medical and administrative quarantine provides for a ban on entry into and exit from an unfavorable territory, the closure of state borders or the introduction of special rules for crossing them.
The periods for which quarantine is introduced are different, but for all diseases there is a general rule - from the moment of recovery of the last patient, the maximum incubation period of a particular disease must pass.
Considering the importance of preventive measures both for the population and for an individual, they need to be approached with understanding. Following simple rules can save you from quite serious problems.
Disease prevention is one of the most important tasks of modern healthcare; it is included in a number of government programs and the compulsory medical insurance system. In addition, even habitual hygiene habits and a correct lifestyle can have a preventive effect.
A person can be susceptible to various diseases from a very early age. They affect life expectancy and its quality, reduce ability to work and even become a cause of disability and social helplessness. Some diseases are characterized by high mortality, others increase the risk of having offspring with various disabilities, others make the sick person dangerous to others and can lead to epidemics. In many cases, preventive measures can prevent the development of diseases or make their prognosis more favorable.
What is prevention
Disease prevention is a complex of medical and non-medical measures of a preventive and health-improving nature. Its main tasks are:
1. prevention of the appearance of various pathological conditions;
2. minimizing the effect of various risk factors;
3. reducing the risk of developing complications of emerging diseases;
4. reducing the rate of disease progression;
5. prevention of chronicity of pathological processes and the development of secondary diseases;
6. reducing the severity of the negative consequences of past diseases;
7. general health promotion.
Competent and comprehensive prevention in general allows you to reduce the incidence and risk of various epidemics, shorten the duration of emerging diseases and quickly restore your ability to work.
Prevention is not just some special medical measures prescribed by a doctor. Daily hygiene, a healthy lifestyle, proper organization of the workplace and compliance with certain rules during periods of epidemics also help prevent the development of many diseases. Even taking care of the environment is a preventative measure.
In addition to individual disease prevention, preventive and health measures can be carried out at the level of the state, regions, and municipalities. Some of them are provided by the employer or the health care system.
What is prevention?
According to WHO definitions, there are several types of prevention. Primary is a variety of measures aimed at eliminating risk factors for the entire population and early detection of diseases in certain groups. It includes various preventive examinations, vaccinations, hygiene education and health education. It also includes improving working conditions in factories and enterprises, improving the overall environmental situation and the microclimate of homes.
Secondary disease prevention is necessary to identify and treat diseases in the early stages in the presence of risk factors. In this case, targeted preventive examinations, medical examinations, preventive treatment and improvement of the health of certain social or labor groups are used. Also, during secondary prevention, training and sanitary and hygienic education of patients, their relatives and people at risk are carried out. For this purpose, specialized information and training programs (schools) are created, aimed at people with certain diseases. This could be diabetes mellitus, dementia (dementia), hypertension and other cardiovascular diseases, multiple sclerosis and many other pathologies with a potentially severe course.
Tertiary prevention is carried out after confirmation of the main diagnosis. It improves the prognosis and alleviates the course of the disease. The set of measures carried out in this case is aimed at the maximum possible restoration of working capacity and the preservation of a person’s social and everyday activity. Medical and psychological adaptation of the sick person to his changed needs and capabilities is also necessary.
In general, all types of disease prevention can be further divided into personal, medical and social activities. At the same time, it is important to adhere to an integrated approach, paying special attention to maintaining your health and strengthening the body's defenses.
Basic measures of individual prevention
Prevention should begin even before the first signs of deterioration in health appear, without waiting for specialized doctor’s recommendations. And at the same time, first of all, the effect of the main risk factors is eliminated or at least minimized. General disease prevention may include:
1. compliance with personal hygiene rules;
2. quitting smoking and drinking strong alcoholic drinks;
3. increasing general physical activity, regularly performing physical education or gymnastics;
4. cleansing your own home from dust, potential allergens and toxins, regularly ventilating and humidifying the air in apartments;
5. transition to a balanced, nutritious diet, while it is important to take into account the composition of the food, its calorie content and the type of heat treatment used;
6. use of clothing appropriate for the season and weather;
7. regular comprehensive preventive examinations, including visits to the doctor, laboratory and instrumental examinations;
8. carrying out routine preventive vaccination in accordance with the national vaccination calendar, as well as additional vaccination before threatening epidemics or travel to Asian and African countries;
9. competent organization of the workplace;
10. compliance with the work and rest regime, as well as the natural biological cycles of sleep and wakefulness;
11. avoiding personally significant stressful situations, timely contacting a specialist to resolve internal psychological conflicts;
12. use of natural factors for hardening, strengthening local protective barriers of the skin and mucous membranes.
In childhood, preventive measures are organized and controlled by parents or adults replacing them. And the obligatory components are the development of correct hygiene habits, routine examinations and vaccinations taking into account the child’s health condition, and compliance with the daily routine. It is also important to monitor the correct seating of children at the table during classes, to ensure harmonious physical and psycho-emotional development.
What is it advisable for everyone to do?
In general, the main preventive measures fit into the concept of a healthy lifestyle and compliance with basic sanitary and hygienic rules. At the same time, physical education, visiting the pool, and daily walking have a training effect on the cardiovascular system. This also supports the functional activity of all areas of the musculoskeletal system, which, together with strengthening the muscle corset, prevents early wear of the intervertebral discs and large joints. Proper nutrition is the prevention of diseases of the digestive tract, hypovitaminosis, obesity and metabolic disorders. And quitting smoking can significantly reduce the risk of developing cancer of the lungs, esophagus and stomach, diseases of the bronchopulmonary and cardiovascular systems.
To prevent infection during the ARVI season, doctors recommend avoiding crowds of people if possible, regularly rinsing your nose and gargling with low-salt solutions, and washing your hands frequently. It is advisable to use personal protective equipment when visiting public places, changing them every 1.5–2 hours. It is also advisable to frequently carry out wet cleaning and ventilation of living spaces.
If a person is at risk for developing a certain disease, he may require additional preventive measures. This could be taking medications, spa treatment, or following a special diet. Such disease prevention is carried out as prescribed by a doctor and is usually supplemented by clinical examination with regularly conducted targeted examinations.
Of course, certain preventive measures are guaranteed by the state and the compulsory medical insurance system. Nevertheless, many diseases can be prevented by adhering to a healthy lifestyle from a young age, taking care of hardening and observing the rules of personal hygiene.
The article was prepared by doctor Alina Obukhova
Topic: INFECTIOUS DISEASES AND THEIR PREVENTION
Infectious process.
Epidemic process.
Federal Law “On Immunoprophylaxis of Infectious Diseases”.
The concept of immunity and its types.
General principles for the prevention of infectious diseases.
INFECTIOUS PROCESS
Infectious diseases include those that develop as a response of the body to the introduction and reproduction of pathogenic microorganisms. A characteristic and distinctive feature of an infectious disease is the ability of the pathogen to spread in the environment of the sick person and cause new cases of disease. Therefore, infectious diseases are called contagious.
The essence of an infectious disease is The infectious process is the result of the confrontation between the patient’s body and the invading microorganisms. During the development of the infectious process, disturbances occur in the structure and function of the affected organs and systems of the body, which leads to disorders of normal human life. The nature of the development of the infectious process, the characteristics of the course of the disease and the outcome of the disease are determined by the following factors:
1. Pathogenic properties (pathogenicity) of the pathogen: a) its virulence (the ability to penetrate the protective barriers of the human body); b) its reproduction (the ability to multiply intensively in the tissues of an infected organism); c) its toxigenicity (the ability to release bacterial poisons or toxins).
2. The protective potential of the human body or its susceptibility to an infectious onset, which depends on: a) resistance or immunity to infection as a result of innate or acquired immunity; b) reactivity, the state of the body’s defense system.
3. Living conditions, determining the possibility of interaction between macro- and microorganisms. Pathogens that can cause an infectious process are called pathogenic, and this property is called pathogenicity. The degree of pathogenicity of a particular pathogen is assessed as virulence. They talk about high or low virulence of pathogenic microbes. The causative agents of infectious diseases are bacteria, viruses, rickettsia (typhus), microscopic fungi, and protozoa.
To denote the state of infection of the body with protozoa, the term “ invasion"(from Lat. Invasion - invasion, invasion).
Entrance gate pathogen (the place where the infectious agent enters the human body):
Leather,
- mucous membranes,
Tonsils.
Infectious dose. For a person to get sick, that is, for an infectious process to occur, an appropriate infectious dose is required, which is different for different pathogens and different for each person. For example, the minimum dose for tularemia is 15 live bacilli, anthrax is 6000, dysentery is 500 million microbial cells .
Specificity of the infectious process. The infectious process is always specific, that is, it depends on the type of pathogen. Vibrio cholerae can only lead to the development of cholera, the influenza virus causes influenza, the dysentery bacillus leads to dysentery, the measles virus leads to measles, etc.
In the process of dynamic development of almost any infectious disease, characteristic periods:
1. Incubation or latent (hidden) period of the disease, which lasts from the moment of infection until the first signs of the disease appear (flu - from several hours to 3 days, AIDS - years);
2. Prodromal period of the disease (harbingers). During this period, symptoms common to all diseases prevail: general malaise, fever, headache, general weakness, and a state of discomfort. At the end of the prodromal period, in some infectious diseases, specific symptoms appear (rash with bark or scarlet fever);
3. Clinical period of the disease (the height of the disease), when the symptoms of the disease are most fully developed, and the specific signs of the disease appear most clearly ; apogee of the infectious process;
4. Outcome of an infectious disease: a) recovery, b) death, c) chronic form, d) recovery with residual effects of the disease or its complications, e) bacterial carriage.
Forms of the course of the infectious process. According to the severity of their course, infectious diseases are divided into 1) spicy: influenza, measles, scarlet fever, chicken pox, etc.; 2) chronic: malaria, tuberculosis, etc. Many infections have acute and chronic forms: dysentery, brucellosis, etc. There are also latent (hidden) course , when the pathogen, multiplying, stays in the body for a long time and does not cause clinical symptoms of the disease. This form of the disease is sometimes called asymptomatic infection.
Bacterial carriage– a special form of relationship between a microorganism and a person. It is most often observed during the period after recovery from an infection. It is typical that the microbe is present in the body, but there are no longer any signs of disease. Healthy bacterial carriage is when no signs of disease develop at all, despite the introduction of a pathogenic microorganism.
Mixed infection– this is an infection with several pathogens (measles and scarlet fever, dysentery and typhoid fever).
Secondary infection– this is when, for example, after a viral infection (flu), pneumonia develops caused by bacterial flora.
Focal infection– for example, a boil, a syphilitic ulcer, tuberculosis can be localized. If the infection spreads throughout the body, it is said to be generalization of the process(for example, sepsis occurs from a boil).
Superinfection – re-infection with the same pathogen when the disease has not yet ended. For example, having not recovered from the flu, a patient may receive an additional “portion” of viruses from another source of infection. The course of the disease becomes more severe.
Reinfection– re-infection with the same type of microbe, but after complete recovery from the previous infection. The course of the disease is easier because there is immunity.
Relapse– this is a return of the disease, an exacerbation during its chronic course.
Remission– a period of relative well-being in the chronic course of the disease between relapses.
Each form of the infectious process has its own clinical and epidemiological significance. For example, latent (latent) infection and healthy bacterial carriage are extremely important epidemiologically, since in these cases patients usually do not seek treatment and for a long time serve as an active source of infection for healthy people. A person who has had an infectious disease during the recovery period is called convalescent.
Causes of exacerbations and relapses of the disease:
Violation of the regime or diet prescribed by the doctor;
Activation of the pathogen that caused the underlying disease (reinfection) due to a decrease in the body’s resistance;
New infection with another type of pathogen of this disease (superinfection) when communicating with people infected with this infectious disease;
Layering of foreign microbial flora (secondary infection) due to violation of hygienic requirements when caring for patients;
Insufficient tension of the formed immunity after a previous infection.
Both the course of the infectious process and the severity of the main manifestations of the disease are influenced by forms of pathogen spread in organism:
1. Bacteremia and viremia– the process of spreading a pathogen through the bloodstream through organs and tissues, or generalization of infection. This process can lead to sepsis;
2. Septicemia (sepsis)– filling of many organs and tissues with microbes (anthrax, pyogenic cocci). Sepsis is characterized by the same clinical picture for different microbes. The septic component during an infectious disease can significantly aggravate the course and prognosis of, for example, salmonella, staphylococcal and meningococcal infections.
3. Septicopyemia is sepsis, leading to the formation of purulent foci in various organs and tissues.
4. Toxinemia leads to poisoning of the body with toxins produced by the pathogen and the development of symptoms of intoxication. Clinical signs of intoxication are caused by toxic damage to the central nervous system (headache, dizziness, nausea, vomiting, convulsions, loss of consciousness, etc.), respiratory system (shortness of breath, suffocation, respiratory arrest), blood circulation (tachycardia, bradycardia, increased or decreased blood pressure , collapse), discharge (polyuria, anuria, dyspepsia, etc.). The toxic component determines the severity of tetanus, botulism, influenza, diphtheria and other infectious diseases.
The macroorganism has a whole series of protective mechanisms against the effects of harmful agents, which are united by the general term - reactivity and as a consequence - resistance, that is, stability.
Resistance plays a decisive role in the occurrence, course and outcome of an infectious disease. Resistance decreases from fasting, lack of vitamins, physical and mental fatigue, cooling, etc., and increases as a result of eliminating harmful factors at work, organizing recreation and everyday life, hereditary and acquired immunity.
Thus, the occurrence of an infectious process and the form of its course in each specific case are determined by the result of the confrontation between the pathogenic agent and the human body. The outcomes of this confrontation can be: a) death of the pathogen, b) the occurrence of an infectious process (disease); c) mutual adaptation (“healthy bacterial carriage”).
EPIDEMIC PROCESS
1. Source of infection that releases the pathogen into the external environment (humans, animals),
2. Factors of pathogen transmission,
3. A susceptible organism, that is, a person who does not have immunity against this infection.
Sources of infection:
1 person. Infectious diseases that affect only people are called anthroponoses (from the Greek anthropos - person, noses - disease). For example, only humans suffer from typhoid fever, measles, whooping cough, dysentery, and cholera.
2. Animals. A large group of infectious and invasive human diseases are zoonoses (from the Greek zoos - animals), in which the source of infection is various types of domestic and wild animals and birds. Zoonoses include brucellosis, anthrax, glanders, foot-and-mouth disease, etc.
There is also a group of zooatroponotic infections, in which both animals and people can serve as the source of infection (plague, tuberculosis, salmonellosis).
Pathogen transmission factors. Pathogens are transmitted to healthy people in one or more of the following ways:
1. Air– influenza and measles are transmitted only through the air; for other infections, air is the main factor (diphtheria, scarlet fever), and for others it is a possible factor in the transmission of the pathogen (plague, tularemia);
2. Water – typhoid fever, dysentery, cholera, tularemia, brucellosis, glanders, anthrax, etc.;
3. Soil– anaerobes (tetanus, botulism, gas gangrene), anthrax, intestinal infections, worms, etc.;
4. Food products- all intestinal infections. Causative agents of diphtheria, scarlet fever, tularemia, plague, etc. can also be transmitted with food;
5. Labor and household items, infected by a sick animal or person, can serve as a factor in transmitting the infectious principle to healthy people;
6. Arthropods– are often carriers of pathogens of infectious diseases. Ticks transmit viruses, bacteria and rickettsiae; lice – typhus and relapsing fever; fleas - plague and rat typhus; flies – intestinal infections and worms; mosquitoes - malaria; ticks - encephalitis; midges - tularemia; mosquitoes – leishmaniasis, etc.;
7. Biological fluids ( blood, nasopharyngeal secretions, feces, urine, semen, amniotic fluid) - AIDS, syphilis, hepatitis, intestinal infections, etc.
The main epidemiological characteristics of the occurrence and spread of an infectious disease are determined by the speed of spread, the vastness of the epidemic territory and the mass coverage of the disease in the population.
Options for the development of the epidemic process:
1. Sporadia(sporadic incidence). Isolated, unrelated cases of infectious diseases occur that do not significantly spread among the population. The ability of an infectious disease to spread in the environment of the sick person is minimally expressed (for example, Botkin's disease).
2. Endemic- group flash. Occurs, as a rule, in an organized team, in conditions of constant and close communication between people. The disease develops from one common source of infection and in a short time affects up to 10 or more people (an outbreak of mumps in a kindergarten group).
3. Epidemic outbreak. Mass spread of an infectious disease that occurs from a number of group outbreaks and covers the entirety of one or several organized groups with a total number of sick people of 100 or more people (intestinal infections and foodborne toxic infections).
4. Epidemic. Mass morbidity of the population, spreading over a vast territory in a short time, covering a city, district, region and a number of regions of the state. The epidemic develops from many epidemic outbreaks. The number of sick people amounts to tens and hundreds of thousands of people (epidemics of influenza, cholera, plague).
5. Pandemic. Global spread of epidemic morbidity among people. The epidemic covers vast territories of various countries on many continents of the globe (influenza pandemics, HIV infections).
Natural focality of infectious diseases- spread of the disease within certain territorial zones.
This phenomenon, when a disease is recorded with great consistency in a certain territory, is called endemic. As a rule, this is zoonotic infections that spread in the corresponding territorial foci among animals with the help of insects that carry the infectious agent. The doctrine of the natural focality of infectious diseases was formulated in 1939 by academician E.N. Pavlovsky. Natural foci of infectious diseases are called nosohabits, and infectious diseases characteristic of territories are called natural focal infections (hemorrhagic fevers, tick-borne encephalitis, plague, tularemia, etc.).
We can call them environmentally caused diseases, since the cause of endemicity is natural factors that favor the spread of these diseases: the presence of animals - sources of infection and blood-sucking insects that act as carriers of the corresponding infection. The nosoareal of cholera is India and Pakistan. Humans are not a factor that can support the existence of a focus of natural infection, since such centers were formed long before the appearance of people in these territories. Such outbreaks continue to exist after people leave (after completion of geological exploration, road and other temporary work). The undoubted priority in the discovery and study of the phenomenon of natural focality of infectious diseases belongs to domestic scientists - Academician E.N. Pavlovsky and academician A.A. Smorodintsev.
Epidemic focus. The object or territory where the epidemic process is unfolding is called an epidemic focus. An epidemic outbreak may be limited to the boundaries of the apartment where the sick person lives, may cover the territory of a preschool institution, school, university, or include the territory of a settlement or region. The number of sick people in an outbreak can vary from one or two to many hundreds and thousands of cases of the disease.
Elements of an epidemic focus:
1. Sick people and healthy bacteria carriers are sources of infection for surrounding people;
2. Persons who have been in contact with sick people (“contacts”), who, if they develop a disease, become a source of spread of infection;
3. Healthy people who, by the nature of their work activities, represent a group at increased risk of spreading infection - the “decreed group of the population” (workers of public catering, water supply enterprises, medical workers, teachers, etc.);
4. The room in which the sick person is or has been, including furnishings and everyday items located in it that contribute to the transmission of the infectious principle to susceptible people;
5. Environmental factors, especially in suburban conditions, that can contribute to the spread of infection (sources of water use and food supplies, the presence of rodents and insects, waste and sewage collection sites);
6. The healthy population in the outbreak area, which has not had contact with patients and bacteria carriers, as a contingent susceptible to infection, not immune from possible infection in the conditions of an epidemic outbreak.
All of the listed elements of the epidemic focus reflect the three main links of the epidemic process: source of infection – transmission routes (mechanism of infection) – susceptible population.
Appropriate anti-epidemic measures should be directed at all elements of the epidemic focus in order to most quickly and effectively solve two interrelated tasks: 1) strictly localize the outbreak within its borders,
prevent “spreading” of the boundaries of the outbreak; 2) ensure the speedy elimination of the outbreak itself in order to prevent mass disease of the population.
Mechanism of transmission of infection consists of 3 phases:
2) presence of the pathogen in the external environment,
3) introduction of the pathogen into a new organism.
With air mechanism infection the infection can be transmitted as by airborne droplets, so and airborne dust. The causative agents of infectious diseases are released into the air from the nasopharynx of a sick person when breathing, when talking, but especially intensely when sneezing and coughing, spreading with droplets of saliva and nasopharyngeal mucus several meters from the sick person. Thus, acute respiratory viral infections (ARVI), whooping cough, diphtheria, mumps, scarlet fever, etc. spread. Airborne dust path spread of infection, when pathogens with air currents are able to spread over significant distances from a sick person, typical for “flying” viral infections (chicken pox, measles, rubella, etc.). With airborne infection, the pathogen enters the body mainly through the mucous membranes of the upper respiratory tract (through the respiratory tract) and then spreads throughout the body.
Fecal-oral mechanism infection differs in that the infectious agents, released from the body of a sick person or a bacteria carrier with its intestinal contents, enter the environment. Then, through contaminated water, food products, soil, dirty hands, and household items, the pathogen enters the body of a healthy person through the gastrointestinal tract (dysentery, cholera, salmonellosis, etc.).
Blood mechanism infection differs in that the main factor in the spread of infection in such cases is infected blood, which penetrates into the bloodstream of a healthy person in various ways. Infection can occur through blood transfusion, as a result of unskilled use of reusable medical instruments, intrauterine transmission from a pregnant woman to her fetus (HIV infection, viral hepatitis, syphilis). This group of diseases includes transmission infections spread through the bites of blood-sucking insects (malaria, tick-borne encephalitis, tick-borne boreliosis, plague, tularemia, hemorrhagic fevers, etc.).
Contact mechanism infection can be carried out both through direct and through indirect (indirect) contact - through infected everyday items (a variety of skin diseases and sexually transmitted diseases - STDs).
Some infectious diseases are characterized by pronounced seasonality (intestinal infections in the hot season).
A number of infectious diseases are age-specific, for example, childhood infections (whooping cough).
Main directions of anti-epidemic measures
As indicated, the epidemic process arises and is maintained only in the presence of three links: the source of infection, the mechanism of transmission of the pathogen, and the susceptible population. Consequently, the elimination of one of the links will inevitably lead to the cessation of the epidemic process.
The main anti-epidemic measures include:
1. Measures aimed at eliminating the source of infection: identification of patients, bacteria carriers, their isolation and treatment; detection of persons who communicated with sick people for subsequent monitoring of their health status in order to promptly identify new cases of diseases and promptly isolate sick people.
2. Measures aimed at stopping the spread of infection and to prevent the expansion of the outbreak boundaries:
A) regime restrictive measures– observation and quarantine. Observation– specially organized medical surveillance of the population in the source of infection, including a number of measures aimed at timely detection and isolation of sick people in order to prevent the spread of the epidemic. At the same time, emergency prophylaxis is carried out with the help of antibiotics, the necessary vaccinations are given, and strict adherence to the rules of personal and public hygiene is monitored. The observation period is determined by the length of the maximum incubation period for a given disease and is calculated from the moment of isolation of the last patient and the end of disinfection in the outbreak. Quarantine– this is a system of the most stringent isolation and restrictive anti-epidemic measures carried out to prevent the spread of infectious diseases;
b) disinfection measures, including not only disinfection, but also disinsection, deratization (destruction of insects and rodents);
3. Measures aimed at increasing the population’s immunity to infection, among which the most important are methods of emergency prevention of the occurrence of the disease:
A) immunization of the population according to epidemic indications;
b) use of antimicrobial agents for prophylactic purposes(bacteriophages, interferons, antibiotics).
The indicated anti-epidemic measures in the conditions of an epidemic outbreak are necessarily complemented by a number of organizational measures aimed at limiting contacts among the population. Sanitary, educational and educational work is carried out in organized groups, and the media are involved. The educational and health education work of teachers with students is becoming important.
Disinfection methods in an epidemic outbreak. Disinfection is a set of measures aimed at destroying pathogens and eliminating sources of infection, as well as preventing further spread. Disinfection measures include:
1) disinfection(methods of destroying pathogens),
2) disinfestation(methods for exterminating insects that carry infectious diseases),
3) deratization(methods of extermination of rodents - sources and spreaders of infection).
In addition to disinfection, there are other ways to destroy microorganisms: 1) sterilization(boiling instruments for 45 minutes prevents infection with epidemic hepatitis), 2) pasteurization– heating liquids to 50-60 degrees for the purpose of disinfecting them (for example, milk). Within 15-30 minutes, vegetative forms of E. coli die.
Disinfection methods. Physical and chemical disinfection methods are used for disinfection. TO physical methods include boiling, autoclaving, heat treatment in dry-heat ovens, disinfection chambers, and ultraviolet irradiation. Chemical methods disinfection is carried out using chemicals with high bactericidal activity (bleach, chloramine, calcium and sodium hypochlorites, Lysol, formaldehyde, carbolic acid). Soap and synthetic detergents also have a disinfecting effect. Biological methods Disinfection is the destruction of microorganisms by biological means (for example, with the help of antagonistic microbes). Used for disinfection of wastewater, garbage and waste.
To carry out focal current and final disinfection in foci of intestinal infections, a 0.5% solution of chlorine-containing disinfectants is used, for airborne infections - 1.0%, in foci of active tuberculosis - 5.0%. When working with disinfectants, you must be careful (use protective clothing, goggles, mask, gloves).
FEDERAL LAW “ON IMMUNOPREVENTION OF INFECTIOUS DISEASES” dated September 17, 1998 No. 157-FZ.
Immunoprophylaxis of infectious diseases– a system of measures carried out to prevent, limit the spread and eliminate infectious diseases through preventive vaccinations.
Preventive vaccinations– introduction of medical immunobiological drugs into the human body to create specific immunity to infectious diseases.
Medical immunobiological preparations– vaccines, toxoids, immunoglobulins and other medicines intended to create specific immunity to infectious diseases.
– a normative act establishing the timing and procedure for carrying out preventive vaccinations for citizens.
Post-vaccination complications caused by preventive vaccinations included in the national calendar of preventive vaccinations, and preventive vaccinations for epidemic indications - severe and persistent health problems due to preventive vaccinations.
Certificate of preventive vaccinations– a document in which preventive vaccinations of citizens are registered.
State policy in the field of immunization(extracts from article 4).
1. State policy in the field of immunization is aimed at preventing, limiting the spread and eliminating infectious diseases.
In the field of immunization, the state guarantees:
availability of preventive vaccinations for citizens;
free provision of preventive vaccinations included in the National Calendar of Preventive Vaccinations, and preventive vaccinations for epidemic indications in organizations of the state and municipal healthcare systems;
social protection of citizens in the event of post-vaccination complications;
use of effective medical immunobiological drugs for immunoprophylaxis.
1. When carrying out immunoprophylaxis, citizens have the right to:
obtaining from medical workers complete and objective information about the need for preventive vaccinations, the consequences of refusing them, and possible post-vaccination complications;
choice of state, municipal or private healthcare organizations or citizens engaged in private practice;
free preventive vaccinations included in the National Calendar of Preventive Vaccinations, and preventive vaccinations for epidemic indications in organizations of the state and municipal healthcare systems;
free medical examination, and, if necessary, medical examination before preventive vaccinations in state and municipal health care organizations;
free treatment in state and municipal healthcare organizations in the event of post-vaccination complications;
social protection in the event of post-vaccination complications;
refusal of preventive vaccinations.
a ban on citizens traveling to countries where, in accordance with international health regulations or international treaties of the Russian Federation, their stay requires specific preventive vaccinations;
temporary refusal to admit citizens to general education and health institutions in the event of the occurrence of mass infectious diseases or the threat of epidemics;
refusal to employ citizens or removal from work, the performance of which is associated with a high risk of contracting infectious diseases.
follow the instructions of medical professionals;
confirm in writing the refusal of preventive vaccinations.
The specified preventive vaccinations are carried out to all citizens of the Russian Federation within the time limits established by the National Calendar of Preventive Vaccinations. (Extracts from Article 9).
Preventive vaccination calendar(Drawed up in accordance with the order of the Ministry of Health of the Russian Federation dated December 18, 1997 No. 375 “On the vaccination calendar)
THE CONCEPT OF IMMUNITY AND ITS TYPES
Organs of the immune system:
· central: bone marrow and thymus (thymus gland);
· peripheral: accumulations of lymphoid tissue in the intestines, lungs, genitourinary system (tonsils, Peyer's patches), lymph nodes, spleen. Peripheral organs of the immune system, like watchtowers, are located on the path of possible movement of genetically foreign substances.
Protective factors are divided into nonspecific and specific.
Nonspecific mechanisms of immunity– these are general factors and protective devices of the body. These include: impermeability of healthy skin and mucous membranes;
impermeability of histo-hematological barriers; the presence of bactericidal substances in biological fluids (saliva, tears, blood, cerebrospinal fluid); excretion of viruses by the kidneys; phagocytic system; barrier function of lymphoid tissue; hydrolytic enzymes; interferons; lymphokines; complement system, etc.
Intact skin and mucous membranes of the eyes, respiratory tract, gastrointestinal tract, and genitals are impermeable to most microbes. The secretions of the sebaceous and sweat glands have a bactericidal effect against many infections (except for pyogenic cocci).
Peeling of the skin - the constant renewal of the top layer - is an important mechanism for its self-cleansing from microbes and other contaminants. Saliva contains lysozyme, which has an antimicrobial effect. The blinking reflex of the eyes, the movement of the cilia of the epithelium of the respiratory tract in combination with the cough reflex, intestinal peristalsis - all this helps to remove microbes and toxins. Thus, intact skin and mucous membranes are first protective barrier for microorganisms.
If a breakthrough infection occurs (trauma, burn, frostbite), then the following line of defense comes into play - second barrier – inflammatory reaction at the site of introduction of microorganisms.
The leading role in this process belongs to phagocytosis (factors of cellular immunity). Phagocytosis, first studied by I.I. Mechnikov, is the absorption and enzymatic digestion of microbes or other particles by macro- and microphages - cells of mesodermal origin - resulting in the liberation of the body from harmful foreign substances. Reticular and endothelial cells of lymph nodes, spleen, bone marrow, Kupffer cells of the liver, histiocytes, monocytes, polyblasts, neutrophils, eosinophils, basophils have phagocytic activity.
Each of these factors and adaptations is directed against all microbes. Nonspecific protective factors neutralize even those substances that the body has not previously encountered. The body's defense system is very vulnerable. The main factors that reduce the body's defenses include: alcoholism, smoking, drugs, psycho-emotional stress, physical inactivity, lack of sleep, and excess body weight. A person’s susceptibility to infection depends on his individual biological characteristics, on the influence of heredity, on the characteristics of a person’s constitution, on the state of his metabolism, on the neuroendocrine regulation of life support functions and their functional reserves; on the nature of nutrition, vitamin supply of the body, on climatic factors and the season of the year, on environmental pollution, living conditions and activities, on the lifestyle that a person leads.
Specific mechanisms of immunity- This is antibody formation in the lymph nodes, spleen, liver and bone marrow. Specific antibodies are produced by the body in response to the artificial introduction of an antigen (vaccination) or as a result of a natural encounter with a microorganism (infectious disease).
Antigens– substances that bear a sign of foreignness (proteins, bacteria, toxins, viruses, cellular elements). These substances are capable of: a) causing the formation of antibodies, b) interacting with them.
Antibodies- proteins that can bind to antigens and neutralize them. They are strictly specific, that is, they act only against those microorganisms or toxins in response to the introduction of which they were produced. Antibodies include: antitoxins (neutralize microbial toxins), agglutinins (glue microbial cells together), precipitins (precipitate protein molecules), opsonins (dissolve microbial cells), virus-neutralizing antibodies, etc. All antibodies are modified globulins or immunoglobulins (Ig), protective substances, elements of humoral immunity. 80-90% of antibodies are found in gamma globulins. So IgG and IgM protect against viruses and bacteria, IgA protects the mucous membranes of the digestive, respiratory, urinary and reproductive systems, IgE is involved in allergic reactions. The concentration of Ig M increases during acute inflammatory processes, Ig G - during exacerbation of chronic diseases. Factors of humoral immunity include interferons and interleukins, which are secreted by a lymphocyte when a viral infection enters the body.
The human body is able to respond with antibody formation to 30 or more antigens simultaneously. This property is used to make combination vaccines.
The “antigen + antibody” reaction occurs both in the human or animal body and in a test tube if the patient’s blood serum is mixed with a suspension of the corresponding microbes or toxins. These reactions are used to diagnose many infectious diseases: the Widal reaction for typhoid fever, etc.
Vaccines, serums. Even in ancient times, people, describing the epidemic, pointed out: “whoever suffered the disease was already safe, because no one got sick twice.” Long before civilization, Indians rubbed smallpox scabs into the skin of their children for preventive purposes. In this case, smallpox was usually mild. The scientific basis for this issue was first given by the English doctor E. Jenner (1749 - 1823), who prepared a smallpox vaccine on calves. After the publication of his work in 1798, smallpox vaccination quickly began to spread throughout the world. In Russia, Catherine the Second was the first to be vaccinated against smallpox. Since 1980, mandatory vaccination against smallpox in Russia has been abolished due to the complete elimination of this disease in the country. Currently, a large number of vaccines and serums are available to prevent infectious diseases by artificially creating immunity in people.
Vaccines– these are preparations from microbial cells or their toxins, the use of which is called vaccination. 1-2 weeks after the administration of vaccines, antibodies appear in the human body.
Vaccinal prevention– the main practical purpose of vaccines. Modern vaccine preparations are divided into 5 groups:
1. Vaccines from live pathogens with weakened virulence (against smallpox, anthrax, rabies, tuberculosis, plague, measles, mumps, etc.). These are the most effective vaccines. They create long-lasting (several years) and intense immunity. The introduced weakened live pathogen multiplies in the body, which creates a sufficient amount of antigen for the production of antibodies.
2. Vaccines made from killed microbes prepared against typhoid fever, cholera, whooping cough, polio, etc. Duration of immunity is 6-12 months.
3. Chemical vaccines – these are preparations not from whole microbial cells, but from chemical complexes of their surface structures (against typhoid fever, paratyphoid fevers A and B, tetanus).
4. Toxoids prepared from exotoxins of the corresponding pathogens (diphtheria, tetanus, staphylococcal, gas gangrene, etc.).
5. Associated vaccines, that is, combined (for example, DTP - associated pertussis-diphtheria-tetanus vaccine).
Serums more often used for treatment (serotherapy) for infectious patients and less often - for the prevention (seroprophylaxis) of infectious diseases. The earlier the serum is administered, the more effective its therapeutic and preventive effect. The duration of the protective effect of serums is 1-2 weeks. Serums are prepared from the blood of people who have recovered from an infectious disease or by artificially infecting animals (horses, cows, donkeys) with microbes. Main types:
1. Antitoxic serums neutralize microbial poisons (antidiphtheria, antitetanus, antisnake, etc.).
2. Antimicrobial serums inactivate bacterial cells and viruses and are used against a number of diseases, most often in the form of gamma globulins.
Gamma globulins from human blood are available against measles, polio, infectious hepatitis, etc. These are safe drugs, since they do not contain pathogens or unnecessary ballast substances. Gamma globulins are also prepared from the blood of hyperimmunized horses against anthrax, plague, smallpox, rabies, etc. These drugs can cause allergic reactions.
Immune serums contain ready-made antibodies and are effective from the first minutes after administration.
Interferon occupies an intermediate position between general and specific mechanisms of immunity, since, being formed upon the introduction of one type of virus into the body, it is also active against other viruses.
Specific immunity divided into congenital (species) and acquired .
Innate immunity inherent in a person from birth, inherited from parents. Immune substances pass through the placenta from mother to fetus. A special case of innate immunity can be considered the immunity received by a newborn through mother's milk.
Acquired immunity occurs (acquired) during life and is divided into natural and artificial.
Natural acquired immunity occurs after suffering an infectious disease: after recovery, antibodies to the causative agent of this disease remain in the blood. Often people, having had measles or chickenpox in childhood, for example, later either do not get sick with this disease at all, or get sick again in a mild, erased form.
Artificial immunity is developed through special medical measures, and it can be active or passive.
Active artificial immunity occurs as a result of preventive vaccinations, when a vaccine is introduced into the body - or weakened pathogens of a particular disease ("live" vaccine), or toxins - waste products of pathogenic microorganisms ("dead" vaccine). In response to the introduction of the vaccine, a person seems to fall ill with the disease, but in a very mild, almost imperceptible form. His body actively produces protective antibodies. And although active artificial immunity does not appear immediately after the vaccine is administered (antibodies take some time to develop), it is quite strong and lasts for many years, sometimes throughout life. The closer a vaccine immunopreparation is to a natural infectious agent, the higher its immunogenic properties and the stronger the resulting post-vaccination immunity.
Vaccination with a live vaccine, as a rule, provides complete immunity to the corresponding infection for 5-6 years, vaccination with an inactivated vaccine creates immunity for the next 2-3 years, and the introduction of a chemical vaccine and toxoid provides protection of the body for 1-1.5 years. At the same time, the more the vaccine is purified, the less likely it is that unwanted, side reactions will occur after its introduction into the human body. Examples of active immunity include vaccinations against polio, diphtheria, and whooping cough.
Passive artificial immunity occurs as a result of the introduction into the body of serum - defibrinated blood plasma that already contains antibodies to a particular disease. Serum is prepared either from the blood of people who have recovered from the disease, or, more often, from the blood of animals that are specially inoculated with the disease and in whose blood specific antibodies are formed. Passive artificial immunity occurs almost immediately after the administration of serum, but since the injected antibodies are essentially foreign, i.e. have antigenic properties, over time the body suppresses their activity.
Therefore, passive immunity is relatively unstable. Immune serum and immunoglobulin, when introduced into the body, provide artificial passive immunity that retains a protective effect for a short time (4-6 weeks). The most typical example of passive immunity is anti-tetanus and anti-rabies serum. The bulk of vaccinations are carried out in preschool age. At school age, revaccination is carried out aimed at maintaining the proper level of immunity. An immunization schedule is a rule-prescribed sequence of vaccinations with a specific vaccine, which specifies the age of the child to be immunized, prescribes the number of required vaccinations against a given infection, and recommends certain time intervals between vaccinations. There is a special, legally approved vaccination calendar for children and adolescents (general schedule of immunization regimens). The administration of serums is used in cases where the likelihood of a particular disease is high, as well as in the early stages of the disease, to help the body cope with the disease. For example, vaccinations against influenza when there is a threat of an epidemic, vaccinations against tick-borne encephalitis before leaving for field practice, after a bite from a rabid animal, etc.
Reactions to vaccination. In response to the introduction of a vaccine into the body, a general, local or allergic reaction (anaphylactic shock, serum sickness) may develop. The general reaction is characterized by chills, fever, general weakness, body aches, and headache. A local reaction usually occurs at the site of injection or inoculation of the immunologic drug and is characterized by skin redness, swelling, and tenderness at the site of vaccine administration. This is often accompanied by itchy skin. Typically, vaccination reactions are mild and short-lived. Severe reactions to the vaccine, requiring hospitalization and special medical supervision, occur quite rarely. Allergic reactions to vaccinations are manifested by an itchy rash, swelling of the subcutaneous tissue, joint pain, temperature reaction, and less commonly, difficulty breathing. Vaccinations to persons who have previously had allergic reactions are allowed only under special medical supervision.
Indications and contraindications for immunization. The main indication for planned, unscheduled and emergency immunoprophylaxis of infectious diseases is the need to create immunity to infection by stimulating the production of specific immunity by the body's immune system.
Contraindications are:
1. Allergic reactions to previous vaccinations. The decision to vaccinate in this case is made by the doctor, and it is carried out in an allergy hospital;
2. Other allergic reactions: respiratory allergies, food and insect allergies. Vaccinations are carried out under the supervision of an allergist;
3. Chronic diseases that occur with disruption of the vital functions of the body; respiration, blood circulation, liver, kidneys, central nervous and endocrine systems;
4. Any acute diseases (flu, sore throat, acute respiratory disease during the acute period and within 1 month after recovery).
If contraindications are identified in some children that provide grounds for an exemption from vaccination for health reasons (medical exemption), the issue of the possibility of vaccination is decided by medical specialists collectively. The rest of the children must be vaccinated, otherwise the infectious disease in the conditions of a children's institution may become widespread.
GENERAL PRINCIPLES FOR PREVENTION OF INFECTIOUS DISEASES
Primary prevention includes the following activities: observance of personal hygiene rules, hardening, preventive and routine sanitary supervision, promotion of knowledge about infectious diseases and methods of their prevention, preventive vaccinations, healthy lifestyle.
Secondary prevention is the early detection of sick people and monitoring of persons who were in contact with patients (hence, knowledge of the signs of the disease), regime-restrictive measures (quarantine, observation), isolation of patients.
Tertiary prevention measures should include timely, adequate and effective treatment.
| Major infectious diseases. Classification, routes of transmission and prevention
Basics of life safety
Grade 10
Lesson 21
Major infectious diseases. Classification, routes of transmission and prevention
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A person is surrounded by microorganisms throughout his life. They are found in the air, water, soil, and are deposited on all objects, including food products. Microbes live and multiply on the skin, in the mouth and nose, on the mucous membrane of the upper respiratory tract, in the intestine, especially in its thick section.
Microorganisms play an important role in life not only of humans, but of the entire organic world of the Earth. They, for example, cleanse soil and water from dead bodies through rotting, fermentation, and decomposition. At the same time, when they get into wounds, they can cause suppuration, and when they penetrate into the internal environment of the human body, they can cause an infectious disease.
Classification of microorganisms and infectious diseases
The entire variety of microorganisms known to modern science from the point of view of their influence on the human body is divided into three types, shown in Diagram 25.
Our country has adopted a classification of infectious diseases, which is based on the mechanism of transmission of the infectious principle and its localization in the body. According to this classification, all infectious diseases are divided into five groups (Table 3).
This or that infectious disease is associated with the penetration of a certain microorganism into the body. For example, the pertussis bacillus causes only whooping cough, the dysentery bacillus causes dysentery, the diphtheria bacillus causes diphtheria, and vibrio cholerae causes cholera.
The emergence and spread of infectious diseases Infectious diseases differ from all others in that they spread quite quickly among people. The massive spread of an infectious disease, significantly exceeding the normal incidence rate, is called an epidemic. If it covers the territory of an entire state or several countries, it is called a pandemic.
To prevent an infectious disease, you need to know how it occurs and how it spreads among people.
All infectious diseases are contagious and are transmitted from a sick person or sick animal to a healthy one. But a healthy person can also serve as a source of infectious disease. After an illness, for still unclear reasons, a paradoxical situation arises. The person recovers and feels well, but the pathogenic microbe continues to be present in his body. An amazing union arises when one organism does not notice the other. This can go on for as long as you like. This is not dangerous for the body itself, but it is extremely dangerous for others, since the pathogenic microbe remains unharmed for a long time and is released into the external environment. This phenomenon is called bacilli carriage, and humans are called bacilli carriers.
Currently known at least five ways of transmission(Fig. 44):
All intestinal infections are transmitted through the fecal-oral route (“diseases of dirty hands”); a pathogenic microbe with feces, vomit of a sick person or a carrier of the bacilli gets onto food, water, dishes, and then through the mouth enters the gastrointestinal tract of a healthy person, causing disease (this is how, in particular, the spread of dysentery occurs);
all viral diseases of the upper respiratory tract, primarily influenza, are spread by airborne droplets: the virus with mucus, when sneezing or talking, enters the mucous membranes of the upper respiratory tract of a healthy person, who becomes infected and becomes ill;
the liquid transmission route is typical for so-called blood infections; The carriers of this group of diseases are blood-sucking insects: fleas, lice, ticks, mosquitoes (this is how plague and typhus are transmitted);
wild and domestic animals serve as carriers of zoonotic infections; infection occurs through bites or through close contact with a sick animal (a typical representative of such diseases is rabies);
Most sexually transmitted diseases are contracted through contact or household contact, through close contact between a healthy person and a sick person (fungal diseases on the skin and nails are also transmitted through the same route).
Immunity
The difference between infectious diseases and all others is that the human body, after recovery, becomes immune to the re-introduction of the microorganism that caused the disease. This immunity is called immunity.
From a biological point of view, immunity is a way of protecting the internal constancy of the body from living bodies or substances that carry signs of genetically foreign information. These bodies and substances are called antigens. These include pathogenic microorganisms, cells and tissues of one’s own body that have become foreign, pollen, some plants, and some food products. In response to their introduction, the body begins to produce specific protein substances - antibodies.
Immunity is a set of protective and adaptive reactions of the human body that occur in response to a strictly defined antigenic stimulus in the form of an infectious disease agent or an artificially introduced antigen (vaccine or toxoid).
The body's immune response is the interaction of an antigen with an antibody. An important feature of immunity is the recognition and distinction of self from foreign.
Immunity is closely related to the functional state of the body and largely depends on environmental factors. Fasting, lack or absence of vitamins (vitaminosis), long-term illness, serious injuries, frequent stressful situations can contribute to a decrease in the body's resistance and the development of an infectious disease.
As a result of an infectious disease or artificial immunization (when an artificially weakened pathogen is introduced into the body), antibodies directed against a specific antigenic stimulus appear in a person’s blood. The number of antibodies is extremely high.
The organs of the human immune system include the bone marrow, liver, spleen and lymphatic system.
Nature provides several types of immunity. Hereditary immunity is associated with a person’s species. It is inherited from parents to their child.
Next, a distinction is made between naturally acquired and artificially acquired immunity. The first is formed as a result of a previous illness. The second is formed actively or passively. During the active formation of artificial immunity, a vaccine is introduced into the body. This is a pathogenic microorganism that has been weakened in some way, but has retained all its harmful properties. Its introduction into the human body causes an infectious disease that occurs in a mild form, but with a very pronounced immune reaction. With the passive formation of artificial immunity, ready-made antibodies (serum or gamma globulin) are introduced into the body.
Immunity formed in one way or another has a certain duration. For passive immunity, it ranges from several weeks to two to three months. Active immunity lasts longer. For example, smallpox vaccination (vaccination) provides a complete guarantee that a person will never get smallpox. The diphtheria or tetanus vaccine (when vaccinated three times) guarantees protection for 10 years. Then repeated vaccination (re-vaccination) is required. We must always remember that a single vaccination for some types of infectious diseases does not provide a lifetime guarantee.
Prevention of infectious diseases
To prevent the spread of infectious diseases, it is necessary to break the links connecting the elements of the general epidemiological chain and simultaneously influence each of its elements.
First element- a sick person or animal. If an infectious disease is suspected, a sick person is isolated and treated. A sick animal is treated differently: if it is an animal valuable to humans, it is treated, in all other cases it is euthanized. The situation is more complicated with bacilli carriers. These are completely healthy people who would never even think of going to the doctor. Therefore, bacteria carriers must be actively identified. It is almost impossible to screen all people for bacillary carriage. Therefore, the survey is carried out selectively. It is subjected to those groups of people who are employed in catering units (buffets, canteens, restaurants) and in child care institutions.
Second element epidemiological chain - mechanisms of its transmission. To prevent the spread of infection, it is necessary to put a barrier on the routes of its transmission and destroy the mechanisms of its spread. To do this, you must follow the following rules in everyday life:
All food products must be cooked; plates, cups, forks, knives must be washed using household chemicals, then rinsed with copious amounts of water; fruits and vegetables must be thoroughly washed in running water; We must not forget about washing our hands before eating and after using the toilet;
for colds, a simple and reliable way to prevent the disease is a regular three-layer gauze bandage, which can be used both at work and at home; It is necessary to allocate individual dishes for the patient and wash them using disinfectants; the patient's handkerchiefs should be boiled and carefully ironed;
an effective way to prevent the spread of blood infections is to destroy or repel insects;
Zoonotic infections need to be prevented in several ways: valuable animals on animal farms must regularly undergo veterinary control; sick animals need to be treated; with a significant increase in the number of carriers and keepers of many infectious zoonotic diseases (these are mice, rats, etc.), they are deratized (destructed);
the reduction of diseases transmitted through contact and household methods can be achieved by increasing the hygienic culture of people, strengthening morality and ethics, stimulating public intolerance towards all manifestations of anticulture, violation of ethical norms and rules (an important element in this process is the education and upbringing of children and adolescents, instilling in them culture of health and healthy lifestyle).
Third element in the general epidemiological chain is directly related to you and me. Currently, the only reliable way to protect yourself from an infectious disease is known: promptly and carefully follow the recommendations of doctors for vaccination and revaccination.
Good nutrition, reasonable physical activity, and a healthy lifestyle also reduce the risk and likelihood of disease.
In all cases of the occurrence of an infectious disease in a team, a system of measures aimed at preventing the spread of the disease, the so-called quarantine, is mandatory. In a simplified form, this is a strict restriction of movement and contacts of people among whom the disease was detected. The duration of quarantine depends on the latent (incubation) period of the identified disease and is calculated from the moment of isolation of the last patient (the incubation period for cholera is 5 days, for dysentery - 7 days, for typhus - 21 days, etc.).
A comprehensive impact on all parts of the epidemiological process of any infectious disease prevents its spread. This requires the efforts of not only medical specialists, but also you and me. Getting vaccinated on time, maintaining a hygienic culture, a culture of health, and cultivating a hygienic worldview is in the interests of each of us.
External signs of an infectious disease
Most infectious diseases are accompanied by fever, chills, weakness throughout the body, and headache. Coughing, sneezing, profuse nasal discharge, sometimes vomiting, repeated loose stools, and pain in the abdominal area often appear. A distinctive feature of many infectious diseases is the appearance of a rash in the form of small reddish spots on the skin in various parts of the body. Sometimes a small bubble filled with clear liquid is visible in the center of the spot. As a rule, the diagnosis of an infectious disease is made on the basis of a bacteriological examination of the patient’s natural wastes (throat swab, genital secretions, skin scrapings, rectal smear).
External signs of an infectious disease do not appear immediately from the moment the pathogenic microbe enters the body, but only after some time. The time from the introduction of a microorganism to the manifestation of the disease is called the incubation period. The duration of the incubation period for each infectious disease is different: from several hours to several weeks and even years.
Incubation or latent period does not mean that nothing happens in the body during this period. On the contrary, there is a fierce struggle between the pathogenic microbe and the body.
In the development of an infectious disease, several successively changing periods are traced: latent (incubation) period, onset of the disease, active manifestation of the disease, recovery. The duration of the periods varies and depends on the nature of the infection.
