How the infection is transmitted give examples. Ways of transmission of infection (artifactual, transmissible, parenteral, airborne, contact, fecal-oral)

1978 was officially marked by the discovery of the stamp of one of the most dangerous viruses in the world - HIV. Until now, scientists are not able to overcome a deadly infection that destroys the human immune system. However, there is a therapy that can maximize the patient's life (up to 15 years from the date of acquisition of the virus). There are several ways to get infected, therefore, in order to prevent a death sentence, it is necessary to become familiar with them and adhere to preventive measures.

Medicine knows three main ways of getting HIV infection into the body:

1. Sexual (if intercourse occurred without barrier contraception).
2. Parenteral (on contact with contaminated blood).
3. Vertical (the process of infection from mother to child, namely in the prenatal period, during childbirth and during feeding).

Attention! HIV infection cannot be transmitted through saliva during kissing. Despite the fact that the virus is transmitted through most human fluids (semen, vaginal discharge, blood), its concentration in saliva is minimal.

During sexual intercourse

It has been determined that it is during unprotected sexual intercourse that HIV infection occurs most often. Semen or vaginal secretions contain enough virus for transmission to a healthy person. Therefore, if there was sexual intercourse without using a condom (the main means of barrier contraception that can protect against the deadly virus), then 100% infection can be confirmed. Once the virus enters the body, it is no longer possible to eliminate or block it.

It is important! A sufficient amount of the virus for infection is found in menstrual blood. If it gets on the mucous membrane of the genital organs of a healthy person (if there are wounds), a mandatory infection will occur.

Oral and anal sex - what's the danger?

Don't forget that oral and anal sex are not safe. With oral contact, if there is damage to the mucous membrane, then HIV can easily enter the body. Therefore, any oral sex with a carrier of the virus increases the risk of infection.

Anal sex is considered more dangerous. At the peak of HIV activation, homosexuals were the main carriers of the virus. This is explained by the fact that the rectum (namely, its mucous membrane) can be easily injured upon penetration, therefore, a favorable condition is created for the direct entry of the virus into the bloodstream.

Risk factors for sexual transmission

If a person has STDs such as gonorrhea, chlamydia, or syphilis, then the likelihood of infection is five times greater. In addition, women are the main risk group; they are the ones who are much more likely to become infected with HIV. This is explained by the fact that the area of \u200b\u200bthe mucous membrane (through which penetration into the body occurs) is much larger than that of men.

This is dangerous! In semen, the concentration of the immunodeficiency virus is higher, so it is more dangerous for a woman to have sex with a sick man. In addition, the vaginal secretion contains much less HIV infection.

When a woman has inflammatory processes, unprotected intercourse is prohibited in order to avoid infection with dangerous infections, as well as HIV. It has been established that with a diagnosis of uterine erosion, a woman becomes infected with the virus much more often. HIV infection is especially dangerous for women during menstruation.

Parietal infection

The penetration of the virus occurs through the use of an infected syringe. Mostly at risk are drug addicts who practice injections with one syringe. Contact of the needle with contaminated blood, and then with healthy blood, leads to HIV infection.

Note! HIV infection through the use of disposable needles has decreased to the extent of the minimum prices for disposable syringes.

In medical practice, there have been cases of infection during surgery, blood transfusion, injections. However, in the modern world, there is practically no such possibility. All blood donors undergo detailed screening for infection (in particular HIV and hepatitis viruses). For injections, only disposable syringes are used. When performing surgical procedures, instruments are used that undergo thorough sterilization and disinfection (several stages of processing).

Statistics! Almost half a percent of carriers of the virus are medical workers who became infected through careless contact with infected blood. Infection is not excluded even if the blood with the virus gets into the eyes.

Vertical infection

Most people, in a measure of ignorance, believe that an infected mother always gives birth to an infected child. However, scientists have found that in this case, only 30% of sick children are born, the remaining 70% remain unaffected by the virus. Basically, infection occurs transplacentally, during the passage of the baby through the birth canal, as well as during breastfeeding.

It is worth considering that a child born to an infected mother is not diagnosed with HIV until the age of three. During these years, antibodies to the virus from the mother may remain in children's blood. After three years, when they disappear, the child is considered healthy. If the child's body develops antibodies to a viral infection, the diagnosis of HIV is confirmed.

An increased risk of infection arises if the mother experiences the following:

• HIV or the final stage - AIDS, manifests itself painfully in a woman;
• inflammatory processes are observed in the reproductive system;
• an increased concentration of the virus is noted in the vaginal secretion;
• negative social status (a woman leads an unhealthy lifestyle, does not eat well, refuses the necessary therapy).

Reference! If the baby is not full-term or is post-term, then the probability of infection is very high.

How can you not get infected?

There are many myths that false HIV transmission routes claim. To dispel misconceptions, you should read the detailed information.

The false path of infection	Why can't you get HIV?
Handshake, hug, touch	If a healthy and infected person does not have lesions on the skin, which are accompanied by bleeding, then infection is impossible. Thus, an integral mucous membrane and skin are a guarantee of health.
Kissing	Despite the fact that saliva is a liquid where the virus can activate, its quantitative indicator is not able to infect another person
Household items (dishes, bedding, personal belongings, etc.)	HIV infection, to the extent of its danger to the body, is not able to exist for a long time in the external environment
Public places	Visiting public places, for example, baths, saunas and other institutions, does not pose a risk of HIV infection, even if a sick person has visited it
Dental services and manicure	Such a possibility is not excluded by contact of instruments with blood. However, in history, not a single case of infection by this route has been noted, since the death of the virus occurs during disinfection

In order to consult a doctor in a timely manner in case of infection and the use of the necessary therapy, you need to know the primary symptoms of HIV, a video will tell about it.

Video - The first symptoms of HIV

Prevention of infection

When entering the body, the virus is activated in all biological fluids. But a sufficient amount to infect a healthy person can be found exclusively in semen, vaginal discharge (menstrual blood), blood, breast milk. Therefore, there are several points of prevention:

1. Avoid contact with body fluids.
2. Have sex only with trusted partners or always use barrier contraception.
3. Use only disposable syringes for injections.
4. If this is a medical worker, then special methods of protection must be used with infected materials (blood, semen).
5. During pregnancy, if a woman is a carrier of the virus, then special therapy is carried out to prevent infection of the fetus.
6. To prevent the baby from becoming infected while passing through the birth canal, specialists perform a cesarean section.

Attention! Women who are diagnosed with HIV are strictly prohibited from breastfeeding. It is best to raise a child on artificial feeding.

If there is a suspicion of HIV or a risk factor for infection, then an urgent need to contact a specialist for further examination of the body. Any atypical colds should be suspected (thus, HIV manifests itself in the early stages). It is recommended to undergo an HIV test every six months, so that in case of confirmation of the diagnosis, ART therapy can be applied in a timely manner and slow down the viral processes in the body. Otherwise, if therapy is abandoned, life expectancy is significantly reduced. Provided that therapy is applied and a healthy lifestyle is observed, an HIV carrier can live a little more than fifteen years (cases of twenty years have been noted).

Epidemic process - This is the process of the emergence and spread of specific infectious conditions among the population: from asymptomatic carriage to manifest diseases caused by a pathogen circulating in the collective.

Epidemiology- a science that:

studies the conditions and mechanisms of the formation of the epidemic process,

develops anti-epidemic measures aimed at preventing and reducing infectious diseases.

The epidemic process determines the continuity of the interaction of its 3 elements:

source of infection;

mechanisms, ways and factors of transmission;

receptivity of the collective.

Turning off any of these links leads to the interruption of the epidemic process.

Social factors of the environment play a decisive role in the development of the epidemic process.

Let us now consider the individual links of the epidemic process.

Source of infection

Source of the causative agent - it is a living or abiotic object, which is the place of natural activity of pathogenic microbes, from which people or animals are infected.

The source of infection can be:

the human body (patient or carrier),

the body of an animal (sick or carrier),

abiotic objects of the environment (water, food, etc.).

Infections in which only a person is the source of infection are called anthroponous .

Infections in which the source is sick animals, but a person can also get sick - zoonotic .

Infections in which environmental objects are the source of infection - sapronous .

Transmission mechanism - a way of moving the causative agent of infectious and invasive diseases from an infected organism to a susceptible one.

This mechanism includes a sequential change of 3 stages:

removing the pathogen from the host's body into the environment;

the presence of the pathogen in environmental objects (biotic or abiotic);

introduction of the pathogen into a susceptible organism.

The following transmission mechanisms are distinguished:

fecal-oral,

aerogenic (respiratory),

blood (transmissible),

pin

vertical (from one generation to another, i.e. from mother to fetus transplacentally)

Transmission factors - these are elements of the external environment that ensure the transfer of microbes from one organism to another.

These include water, food, soil, air, live arthropods, and environmental objects.

Transmission routes - these are specific elements of the external environment or their combination, ensuring the entry of the pathogen from one organism to another under certain external conditions.

The fecal-oral transmission mechanism is characterized by:

alimentary (food),

1. contact (indirect contact) transmission path.

The aerogenic transmission mechanism is characterized by:

airborne

air and dust.

The transmission gear mechanism is characterized by:

parenteral

The contact (direct) transmission mechanism is characterized by:

1. contact-sexual (direct contact).

The transplacental pathway is characteristic of the vertical transmission mechanism.

The Russian scientist-epidemiologist L.V. Gromashevsky formulated the law of the correspondence of the transmission mechanism with the localization of the pathogen in the body.

According to this law, all infectious diseases by the mechanism and main routes of transmission are classified as follows:

intestinal infections;

respiratory tract infections (respiratory)

vector-borne (or blood-borne) infections;

infections of the outer covers.

In accordance with this division, for each of the groups, the main routes of transmission of infection are inherent:

for intestinal infections - it is alimentary, water and contact-household;

for respiratory - airborne and airborne dust;

for transmissive - through vectors, parenteral and sexual;

for infections of the outer covers - wound and contact-genital transmission.

In addition to these basic mechanisms, with some infections, a vertical route of transmission of the infection from the mother to the fetus and through the germ cells is possible.

There are 5 main routes of transmission, which will be listed below.

The artifactual route of transmission is ...

An artifactual route of transmission is an artificial infection in which the spread of an infectious agent occurs as a result of iatrogenic human activity. An example is infection or hepatitis during operations or hemoplasmotransfusion.

The transmission route of infection is ...

The vector-borne route of infection is infection through insects:

• flies (Botkin's disease, typhoid fever, dysentery, anthrax),
• lice (typhus),
• bedbugs (relapsing fever),
• fleas (plague),
• mosquito - anopheles ().

It is necessary to destroy these insects, keep them out of living quarters and prevent flies from coming into contact with water and food.

The parenteral route of transmission is ...

The parenteral route of transmission is a type of artifactual infection mechanism, in which the pathogen enters the bloodstream directly.

Airborne transmission of infection is ...

Airborne droplet transmission of infection is an infection through the air, into which at a distance of 1-1.5 m when talking, coughing and sneezing of patients, the smallest splashes and drops of saliva and nasal mucus containing pathogens - droplet infection (, tonsillitis, diphtheria , whooping cough, measles, scarlet fever,). When these splashes and drops dry, pathogens remain in the dust for a long time (tuberculosis) - a dust infection. Infection occurs by inhalation of pathogens.

The contact route of transmission is ...

The contact route of transmission of infection is, as the name implies, the spread of an infectious agent through direct contact. It can be carried out by several mechanisms:

• Contact with a sick person (smallpox, chickenpox, measles, scarlet fever, mumps, Botkin's disease, etc.). Therefore, it is forbidden to enter an apartment where there are patients.
• Infection from bacilli. The causative agents of some infectious diseases (typhoid fever, diphtheria, scarlet fever) continue to live in the body of a recovered person for a long time. Bacillary carriers can also be people who have not had this infectious disease, but carry its pathogen, for example, during an epidemic of diphtheria, up to 7% of healthy schoolchildren have diphtheria bacilli in their throat or nose. Bacillary carriers are the distributors of pathogens.

The fecal-oral route of transmission is ...

The fecal-oral route of transmission of infection is a mechanism of infection in which the pathogen enters the digestive tract. Infectionists distinguish three main mechanisms of transmission of infection:

1. Through the discharge of patients: feces (typhoid fever, dysentery), urine (gonorrhea, scarlet fever, typhoid fever), saliva, nasal mucus. Infection also occurs when pathogens enter the mouth, so it is imperative to educate children in the habit of thoroughly washing their hands before eating.
2. Contact with objects that an infectious patient touched (linen, water, food, dishes, toys, books, furniture, room walls). Therefore, disinfection is carried out and it is recommended to use only your own dishes and things.
3. Pathogens of gastrointestinal diseases (paratyphoid fever, typhoid fever, dysentery, Botkin's disease) and tuberculosis penetrate into the body through unboiled water and milk, unwashed fruits and vegetables. Water and milk must be boiled, and fruits and vegetables must be doused with boiling water or peeled.

Types of transmission of the pathogen

There are six main types of transmission mechanisms for the pathogen:

• airborne (aerosol)
• contact
• transmissible
• fecal-oral (alimentary)
• vertical (including transplacental)
• blood contact

Airborne

Airborne transmission mechanism - the mechanism of transmission of infection, in which pathogens are localized in the mucous membrane of the respiratory tract, from where they enter the air (when coughing, sneezing, etc.), stay in it in the form of an aerosol and are introduced into the human body when the infected air is inhaled.

Contact

Contact mechanism of transmission - the mechanism of transmission of infection, in which pathogens are localized on the skin and its appendages, on the mucous membrane of the eyes, oral cavity, genitals, on the surface of wounds, from them to the surface of various objects and upon contact with a susceptible person (sometimes through direct contact with source of infection) are introduced into his body.

Transmissible

Transmissive mechanism of infection transmission (also called "blood-borne") - a transmission mechanism in which the pathogen is in the bloodstream and lymph, is transmitted by the bites of specific and non-specific vectors: the bite of a blood-sucking arthropod (insect or tick).

Fecal-oral

Fecal-oral transmission mechanism - the mechanism of transmission of infection, in which the localization of the causative agent of the infection mainly in the intestine determines its excretion from the infected organism with feces (feces, urine) or vomit. Penetration into a susceptible organism occurs through the mouth, mainly by ingestion of contaminated water or food, after which it is again localized in the digestive tract of the new organism.

Transplacental

Transplacental transmission of infection - in which the pathogen is transmitted from mother to fetus during pregnancy.

Hemocontact

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See what the "Mechanism of transmission of the pathogen" is in other dictionaries:

THE MECHANISM OF TRANSMISSION OF THE INFECTION AGENT - the mechanism of transmission of the causative agent of infection, the evolutionarily developed biological adaptability of each type of pathogenic microbes to certain paths of movement from the source of the causative agent of the infection to healthy susceptible animals (people), which ... ... Veterinary encyclopedic dictionary

ACUTE INTESTINAL INFECTIONS - honey. Acute intestinal infections (AEI) are a group of infectious diseases caused by various microorganisms (bacteria, viruses), united by a similar nature of clinical manifestations in the form of gastrointestinal dysfunction and symptoms of extraintestinal disorders. ... ... Handbook of diseases

- (late lat. infectio infection) a group of diseases that are caused by specific pathogens, characterized by infectiousness, cyclic course and the formation of post-infectious immunity. The term "infectious diseases" was introduced ... ... Medical encyclopedia

I The epidemic process is defined as a chain of successive infectious conditions, from asymptomatic carriage to manifest diseases caused by infectious agents circulating in the collective (invasion). It appears as ... ... Medical encyclopedia

A / H1N1 virus under an electron microscope. The diameter of the virus is 80 120 nm. ... Wikipedia

- [Greek. meninx, meningos meninges + kokkos grain, bone (fetus); infection] infectious disease, for which the most typical lesion of the nasopharyngeal mucosa and generalization in the form of specific septicemia and purulent ... ... Medical encyclopedia

A / H1N1 virus under an electron microscope. The diameter of the virus is 80 120 nm. "Swine influenza" is a conventional name for a disease in humans and animals caused by strains of the influenza virus, which are characterized by an epidemic ... ... Wikipedia

Under an electron microscope. The diameter of the virus is 80 120 nm. "Swine influenza" is a conventional name for a disease in humans and animals caused by strains of the influenza virus, which are characterized by epidemic spread in ... ... Wikipedia

Fecal-oral transmission mechanism

The law of epidemiology on the correspondence of the transmission mechanism to the specific localization of the pathogen in the human body

The localization of the pathogen in the body and the mechanism of its transmission from one host to another is a continuous chain of mutually conditioning phenomena that ensures the preservation of the pathogen in nature.

Transmission mechanism - an evolutionarily developed way of moving a pathogen from one host organism to another, providing it with the maintenance of a biological species.

Transmission routes - a set of environmental factors that ensure the transfer of the pathogen from one organism to another in the specific conditions of the epidemiological situation. Assessed by the end factor that caused the infection.

The transmission mechanism corresponds to the main localization of the pathogen in the host organism.

Phases of the pathogen transmission mechanism:

1. Isolation of the pathogen from the body

3. Introduction into a new organism

Transmission mechanisms:

1. Fecal-oral - gastrointestinal tract (typhoid fever, cholera, dysentery, HAV, HEV)

2. Aerogenic - respiratory tract infections (diphtheria, whooping cough, scarlet fever, measles, rubella ...)

3. Transmissible - pathogen in the blood (tularemia, HFRS, tick-borne encephalitis, malaria ...)

4. Contact - external integuments, mucous membranes (anthrax, tetanus, rabies, foot and mouth disease, STIs)

5. Vertical

6. Artificial (artifical)

1-5 - natural mechanisms.

Transmission factors- elements of the external environment that ensure the transfer of the pathogen from one organism to another

ü Food products

ü Live vectors

ü Household and household items

It is characteristic of intestinal infections, the causative agent of which is located in the digestive tract.

Transmission routes:

1. Alimentary (food) - salmonellosis, shigellosis, yersineosis, typhoid fever, etc.

2. Water - cholera, Escherichiosis, HAV, etc.

3. Contact-household - shigellosis, Escherichiosis, less often other AEI.

Transmission factors:

ü Plumbing

ü Well

ü Spring

ü Marine

2. Food products

ü Dairy (milk, sour cream, cottage cheese, butter, cheese, ice cream)

ü Cream

ü Meat (salmonellosis) - primary (when slaughtering livestock), secondary (infection of meat products with bacteria carriers)

ü Beer (Shigella flexnera)

3. Household appliances (dishes, household items, dirty hands, toys, banknotes, common items)

Transmission routes:

1. Airborne - with microorganisms unstable in the external environment (meningococcus, ARVI ...)

2. Air-dust - with stable, maintaining viability for a long time (mycobacterium tuberculosis)

Transmission factor: air.

Phases:

1. The act of excretion of the pathogen (when sneezing, coughing, breathing, talking)

Spray can

ü Droplet phase (meningococcus, pertussis virus, measles, rubella, chickenpox)

ü Drying

ü Subsidence

ü Dust phase

2. Stay in the external environment

3. Penetration into a susceptible organism (inhalation)

This mechanism can be used as a bioterrorist act.