Groups at increased risk of contracting HIV infection. When infection does not occur

HIV infection is a plague not only of the 20th, but also of the 21st century. Every year, the number of people infected with HIV, unfortunately, is steadily growing. Doctors around the world are sounding the alarm, calling on humanity to use common sense - the infection is spreading at cosmic speed, and now there are very few areas left in which there is not at least one sick person. However, despite the scale of the disaster, every attempt and compliance with precautions increases the chances of victory in this fight for the life and health of the population of the entire globe.

To know how to effectively fight the disease and prevent infection, it is important to first learn what HIV is. The ways of transmission of this infection, its differences from AIDS, symptoms and basic precautions are the topic of our conversation today. So...

What is HIV?

The abbreviation HIV stands for human immunodeficiency virus. Already based on the name, it becomes clear that pathogenic bacteria attack the immune system. The target is leukocytes, which help eliminate various harmful microorganisms and fungi from the body. Once the number of white blood cells decreases, a person becomes extremely susceptible to various types of infectious diseases.

People with HIV are doomed to death, since the immunodeficiency virus acts throughout life, and a person can die even from the most primitive ARVI. However, it is possible to survive with HIV infection for two to three years, or for ten years.

Are HIV and AIDS the same thing?

HIV should not be confused with AIDS. AIDS is the very last stage of the disease we are considering. The acronym stands for “acquired immunodeficiency syndrome,” and the statement that you can become infected with this disease is completely false. It is HIV that causes AIDS, so it is quite possible to eliminate the signs of the syndrome, but alas, it is possible to cure the virus itself. In this regard, AIDS is considered fatal, since it occurs at the very end of the disease and invariably leads to a tragic end.

Source or carrier of HIV infection

People infected with HIV are called carriers this virus, regardless of the stage of the disease, whether incubation or terminal period. Infection from the source of the disease is possible at any stage of the disease, but the greatest likelihood is contact with the carrier at the end of incubation and at a later date. Only a person can be HIV-infected.

Now that we have figured out what HIV is and who can become a carrier of the virus, let’s look at possible ways contracting this infection.

Routes of HIV transmission

HIV infection can be transmitted in only three ways:

1. From mother to newborn.
2. Sexually.
3. Through blood.

Theoretically, there is another method of infection - transplantation and transplantation various organs and tissues from one person to another, as well as artificial insemination of women. However, due to careful testing and numerous checks of biological material, the possibility of infection with the virus is thus reduced to absolute zero.

Note that the paths mentioned above are listed from least common to most relevant. Let's consider each of them separately.

Transmission of HIV from mother to newborn

HIV infection can occur both during pregnancy and childbirth, and subsequently during breastfeeding. This method of infection is currently the least possible of the three above, since modern medicine offers various preventive measures based on the use of chemotherapy. They reduce the risk of having HIV-infected children by several percent. As for breastfeeding, only artificial formula is used.

HIV infection can be confirmed in a child only after he reaches 1.5 years of age. However, it is possible to obtain some information earlier, during the first month of the baby’s life. To do this, the child's blood is taken for analysis, but the result will be only 90% reliable.

In this regard, every pregnant woman should be required to undergo an HIV test in order to avoid aggravation of the situation and transmission of infection to the fetus through inaction or, conversely, unwanted effects on the body by some medicines, the use of which is unacceptable in the above conditions.

Sexual transmission of HIV

Unprotected sexual intercourse is a real scourge among homosexuals, drug addicts, prostitutes, as well as those who practice casual sex. The risk of infection among representatives of this contingent is off the charts. Moreover, HIV is no less common in women than in men. According to statistics, more than 85% of respondents were infected through sexual contact. If, before contact with the carrier, a person already had any inflammatory diseases, then the risk of infection increases several times.

Transmission of HIV through blood

Infection with HIV infection through blood is the most common way of acquiring the disease. "Earn" dangerous virus possible via:

Shared use of disposable syringes and needles;

Non-sterile surgical instruments;

Violation of hygienic rules for the operation of cosmetology and dental equipment;

Transfusion of blood and plasma without prior testing.

How not to get infected with HIV

To be fully educated on this issue, you should know how you can’t get HIV. We described the routes of transmission of the virus above, but now let us remember factors that should in no way affect the position of an infected person in society:

Bodily contact, including kissing, provided that there are no open scratches, wounds, or abrasions on the skin;

Food and drinking liquids;

Household items;

Public toilets, showers, swimming pools, seats and handrails in transport;

Cough, sneezing, sweat, tears, breathing;

Animals and insects, including blood-sucking ones.

Despite this, there are many myths that you can catch the virus at any time. Even if you sleep with an infected person in the same bed and eat from the same plate, you will never be able to become infected with HIV - transmission routes work exclusively in three cases already known to us.

Conditions for HIV infection

Despite the ease with which one can catch a known virus, during its transmission certain conditions must be met:

The infection must enter the endangered organism with special biological secretions that have an increased concentration of bacteria;

For the lesion to grow, penetration into the body itself is necessary. If the covers are not damaged, this is simply impossible.

The virus is present in all fluids that the human body is capable of producing. But at the same time, its concentration in some secrets is much greater than in others. For example, saliva, sweat, tears. If urine enters a foreign body, it cannot transmit HIV. The route of transmission is not important only if the surface of the skin or mucous membranes is not damaged. In other cases, whole liters of such liquids will be required to infect a healthy body.

But secretions such as sperm, pre-ejaculate, vaginal secretions, as well as breast milk and blood already carry potential danger. After any of the mentioned liquids enters a fertile environment, the level of susceptibility of the affected organism comes into force. The virus will manifest itself in any case, but how early depends on genes, a person’s susceptibility to various diseases, the presence of aggravating conditions and other factors.

Symptoms of HIV

Now let's talk about how the virus can manifest itself externally. Despite the fact that HIV can be determined in men or women by initial stages in most cases it is impossible, but there are still some symptoms associated with this disease.

Each organism is individual, so determine characteristic features quite problematic. The latest HIV statistics indicate that the first symptoms can be detected both two weeks after infection and two months later. In some cases, symptoms can disappear for an indefinite period, only to subsequently reappear with renewed vigor.

If you experience symptoms such as:

Increase lymph nodes;

Regular occurrence of herpes;

Increased body temperature;

Stomatitis;

Dermatitis;

Dramatic weight loss;

Frequent respiratory diseases;

Feverish manifestations;

Indigestion;

Candidiasis and vaginal inflammation in women,

But you shouldn’t blame everything on various viral and colds. Carefully analyze your behavior Lately and availability possible factors, which could contribute to infection with the virus, and go to the doctor, and then donate blood for HIV.

It is worth remembering that the virus behaves very secretively in the initial stages. Even laboratory tests are unable to recognize a hidden infection. And only after a few years the disease can manifest itself so clearly that doctors no longer have any doubts about the person’s infection.

How long do people live with HIV?

This question is the most pressing for those who have received an HIV-positive result. If we compare the possibilities modern medicine With what was available 10-15 years ago, it is easy to notice that infected citizens began to live a little longer. However, the main criterion for this was not only the improvement of medications and technologies, but also the recognition and acceptance by patients of some undeniable requirements regarding the new way of life, which they now have to comply with.

The results of studying the life expectancy of HIV-infected people cannot be subsumed under any possible logical pattern. Some carriers of the virus can live up to old age, others do not last even 5 years. If we average all the indicators, it turns out that HIV-infected people live about 10-12 years, but all the boundaries are so blurry and relative that there is no point in clearly stating the duration.

The only thing that can help prolong the patient’s life is strict adherence to the following rules:

Eliminate (or at least significantly limit) the amount of nicotine, alcohol and drugs consumed;

Perform regularly physical exercise, ideally, go in for sports;

Take vitamin complexes and means to strengthen the immune system;

Switch to a healthy diet;

Visit your healthcare professional regularly.

Although it is too early to talk about a complete victory over the virus, the fact that scientists are currently able to control it speaks for itself.

Ways to protect yourself from HIV infection and precautions

Knowledge is the most important weapon against HIV. We already know the routes of transmission of infection, so now all that remains is to add to this awareness. Preventive measures to prevent infection with the virus are as follows:

Using condoms during sexual intercourse. Do not allow your partner’s sperm, blood, or vaginal fluid to enter your body;

Choose your sexual partners carefully. The more third-party and unprotected sexual relationships your boyfriend or girlfriend has, the higher the likelihood of getting an infection;

Be faithful to your partner yourself;

Avoid group sex;

Do not take other people's personal hygiene items (razors, toothbrushes);

Be extremely careful and attentive in unfamiliar areas in public places;

Watch what your children play with. There are frequent cases of used syringes being found on sites and in sandboxes;

Use only sterilized surgical instruments and syringes no more than once. Demand the same from tattoo artists and cosmetologists whose services you have applied for;

If you are a pregnant woman suspected of having the immunodeficiency virus, do not be lazy to donate blood for HIV. If you receive a positive result, seek help from a specialist. He will appoint necessary medications to minimize the risk of giving birth to an unhealthy child.

The most main danger HIV infection is that the virus does not manifest itself in any way for a very long time. During this period, the carrier of the disease can infect other people without suspecting anything about their condition. That is why it is important to know about the existence of a disease such as HIV, the ways of its spread and the precautions that must be taken in order to fully protect yourself and your loved ones from harm.

HIV takes everything every year more lives. The number of infected people is not decreasing. The virus has been studied quite well by doctors and ways to prolong the patient’s life have been identified, although there is still no vaccine to treat HIV infection. It is known how HIV is transmitted; It is known that without treatment the disease progresses to the most severe stage - AIDS. To protect yourself from infection, you need to know how HIV is transmitted.

The main danger of the human immunodeficiency virus is weakening immune system due to the destruction of its cells. The virus is detected only through laboratory tests.

How HIV is transmitted has long been known. The infection can be transmitted from person to person through biological fluids: breast milk, blood, seminal fluid, vaginal fluid. For the virus to spread, contact with a carrier of the disease is necessary and healthy person. Through this damage, virus cells enter the bloodstream and the person becomes infected.

HIV infection can be acquired in the following ways:

• sexual;
• parenteral;
• vertical (from mother to child).

There are also natural and artificial routes of infection.

TO artificial routes transmission of HIV infection include:

• (for example, for) without a sterilization process;
• transfusion of contaminated blood or components of this blood;
• organ or tissue transplantation from an HIV-infected donor;
• use of razors or other household appliances, .

Natural routes of transmission of HIV infection are associated with sexual contact, as well as with the mother-child system.

Infection with AIDS is impossible through ordinary household contact.

Sexual transmission of the disease

The most likely route of infection is sexual intercourse. The risk of becoming infected from an infected person is very high. When friction occurs, microdamages occur on the mucous membranes of the genitals. Through them, virus cells enter the blood of a healthy partner and begin their destructive effect. Unprotected sexual contact greatly increases the risk of infection. This is especially true for people who often change sexual partners.

The risk of developing a disease during anal sex is much higher than during traditional contact. There are no glands in the anal area capable of producing secretion. Anal sexual intercourse inevitably leads to microtrauma. The moment a condom breaks, you can easily become a carrier of the virus. It is easier for a woman to become infected from an infected man than vice versa.

If a couple is homosexual, then the risk of contracting HIV for the passive partner is higher than for the active partner. Among same-sex couples, lesbian sex is considered safe. Infection with a virus through a vibrator is unlikely. It is still recommended to wash the device with a hygiene product when using it together.

The probability of infection during regular sex without a condom with a carrier of the virus is one hundred percent.

The risk of HIV infection increases greatly if partners have ulcers, inflammatory processes on the mucous membranes of the genital organs, or if HIV infection is accompanied by sexually transmitted diseases.

Parenteral route of transmission of HIV infection

Over the past decade, the likelihood of contracting HIV through this route has decreased significantly. This risk of infection exists in people with drug addiction. Using one syringe for several people increases the likelihood of infection with the immunodeficiency virus.

There was a wide public outcry when, in a hospital in the Stavropol Territory, a nurse gave injections to children, presumably with one syringe.

Visiting beauty salons at home increases the possibility of acquiring infection through contaminated manicure instruments. It is especially dangerous to use needles without treatment in tattoo parlors. Sterilization of medical instruments eliminates the risk of infection.

Transfusion of untested blood laboratory conditions, also refers to the specified route of disease transmission. At the present stage of development of the security system, this risk has been minimized.

Vertical route of transmission of HIV infection

The myth that an exclusively sick child is born from a pregnant mother who is HIV-positive has been debunked. The likelihood of a child becoming infected from an HIV-infected mother is quite high.

Vertical transmission of the virus is possible from a sick mother to the fetus in utero; during the child's passage birth canal or after birth, through breast milk.

But proper management of pregnancy and delivery reduces the risk. HIV infection in a pregnant woman is an indication for childbirth by caesarean section. If the baby is not infected in the womb, operative delivery protects him from infection in the birth canal.

Up to three years, the mother's antibodies remain in the child's blood. If after the indicated age the antibodies disappear, it means that the pregnant mother did not transmit the virus to the child.

At-risk groups

Risk groups for HIV infection include:

• persons with drug addiction;
• people who prefer promiscuity and do not use barrier protection;
• women with reduced social responsibility;
• prisoners serving sentences in colonies;
• medical workers who work in health care organizations that are intended for people with HIV-positive status;
• medical personnel who have direct contact with various human biological fluids;
• persons in need of organ or tissue transplantation, blood transfusion;
• whose mothers are HIV-positive.

Subject to the most simple rules hygiene and careful attention to professional duties, the chance of contracting HIV is minimal. Surgeons, dentists, and laboratory technicians who are at risk for HIV infection should pay special attention to their health.

There are people who, knowing about their HIV-positive status, deliberately enter into unprotected sexual intercourse with a healthy partner. In Russia, criminal liability is provided for this act.

How not to get infected with HIV

• The possibility of contracting HIV through household means exists only in theory. Virus cells are unstable in the external environment. Practical sources do not describe a single case of household acquisition of the virus.
• HIV is not transmitted through saliva. Indeed, virus cells are found in saliva. However, their number is so small that it is not enough to cause infection.
• When hitting healthy skin No infection occurs through sweat or tears from an infected person.
• The immunodeficiency virus is not transmitted by airborne droplets.
• The risk of disease transmission in public places, during handshakes and hugs is reduced to zero.
• The likelihood of inheriting HIV is also zero.
• The likelihood of infection is small, but it still exists if oral cavity one or both partners have bleeding wounds or scratches. There are only a few precedents recorded in the world when a person became infected orally.
• In principle, it is impossible to become infected with AIDS. AIDS is not a separate disease, it is the final stage of HIV infection, when the immune system is completely suppressed. The development of this stage can be avoided if you consult a doctor in a timely manner and follow all instructions.

HIV prevention

The methods of transmission of HIV are known. This article describes ways in which the likelihood of contracting HIV is minimal or zero. The main preventive measures are aimed at health education of the population. Subject to basic rules of behavior and hygiene, an infected person will not be at risk of becoming infected.

HIV infection- an anthroponotic viral disease, the pathogenesis of which is based on progressive immunodeficiency and the development as a result of secondary opportunistic infections and tumor processes.

History of the discovery of HIV
The human immunodeficiency virus was discovered in 1983 as a result of research into the etiology of AIDS. The first official scientific reports on AIDS were two articles about unusual cases of Pneumocystis pneumonia and Kaposi's sarcoma in homosexual men, published in 1981. In July 1982, the term AIDS was first proposed to designate the new disease. In September of the same year, based on a series of opportunistic infections diagnosed in (1) homosexual men, (2) drug addicts, (3) patients with hemophilia A, and (4) Haitians, AIDS was first given full definition like diseases. Between 1981 and 1984, several works were published linking the risk of developing AIDS with anal sex or the influence of drugs. At the same time, work was carried out on a hypothesis about the possible infectious nature of AIDS. The human immunodeficiency virus was independently discovered in 1983 in two laboratories:
. at the Pasteur Institute in France under the direction of Luc Montagnier.
. at the National Cancer Institute in the USA under the leadership of Robert C. Gallo.

The results of studies in which a new retrovirus was first isolated from patient tissue were published on May 20, 1983 in the journal Science. These articles reported the discovery of a new virus belonging to the HTLV group of viruses. The researchers suggested that the viruses they isolated could cause AIDS.

On May 4, 1984, researchers reported the isolation of the virus, then called HTLV-III, from the lymphocytes of 26 of 72 examined AIDS patients and 18 of 21 patients with a pre-AIDS condition. The virus could not be detected in any of the 115 healthy heterosexual individuals in the control group. The researchers noted that the low percentage of virus isolation from the blood of AIDS patients is caused by a small number of T4 lymphocytes, cells in which HIV presumably multiplies.

In addition, scientists reported the discovery of antibodies to the virus, the identification of previously described and previously unknown HTLV-III antigens from other viruses, and the observation of virus multiplication in the lymphocyte population.

In 1986, it was discovered that the viruses discovered in 1983 by French and American researchers were genetically identical. The original names of the viruses were dropped and one was proposed common name- HIV.

In 2008, Luc Montagnier and Françoise Barré-Sinoussi were awarded the Nobel Prize in Physiology or Medicine “for their discovery of the human immunodeficiency virus.”

Reservoir and source of infection- a person infected with HIV, in all stages of infection, for life. Natural reservoir HIV-2 - African monkeys. The natural reservoir of HIV-1 has not been identified; it is possible that it could be wild chimpanzees. In laboratory conditions, HIV-1 causes a clinically silent infection in chimpanzees and some other species of monkeys, resulting in rapid recovery. Other animals are not susceptible to HIV.

The virus is found in large quantities in the blood, semen, menstrual flow and vaginal secretions. In addition, the virus is found in human milk, saliva, lacrimal and cerebrospinal fluids. The greatest epidemiological danger is represented by blood, semen and vaginal secretions.

The presence of foci of inflammation or disruption of the integrity of the mucous membranes of the genital organs (for example, cervical erosion) increases the likelihood of HIV transmission in both directions, becoming weekend or entrance gate for HIV. The probability of infection during a single sexual contact is low, but the frequency of sexual intercourse makes this route the most active. Household transmission of the virus has not been established. Transmission of HIV from mother to fetus is possible due to defects in the placenta, leading to the penetration of HIV into the bloodstream of the fetus, as well as trauma to the birth canal and child during childbirth.

The parenteral route is also implemented through transfusion of blood, red blood cells, platelets, fresh and frozen plasma. Intramuscular, subcutaneous injections and accidental injections with an infected needle account for an average of 0.3% of cases (1 case in 300 injections). Among children born from infected mothers or fed by them, 25-35% are infected. It is possible for a child to become infected during childbirth and through breast milk.

Natural sensitivity of people- high. Recently, the possibility of the existence of minor genetically different population groups, found especially often among Northern European peoples, who are less likely to become infected through sexual contact, has been considered. The existence of these deviations in susceptibility is associated with the CCR5 gene; people with a homozygous form of the gene are resistant to HIV. Recent data indicate that the cause of immunity to HIV infection may be specific IgA found on the mucous membranes of the genital organs. People infected over the age of 35 develop AIDS twice as quickly as those infected at a younger age.

The average life expectancy of those infected with HIV is 11-12 years. However, the advent of effective chemotherapy drugs has significantly extended the life of HIV-infected people. Among the cases, people of sexually active age predominate, mainly men, but the percentage of women and children increases every year. In recent years, Ukraine has been dominated by parenteral route infections (when one syringe is used by several people), mainly among drug addicts. At the same time, an increase in the absolute number of transmissions during heterosexual contacts is noted, which is understandable, since drug addicts become sources of infection for their sexual partners. The incidence of HIV infection among donors has increased sharply (more than 150 times compared to the beginning of the epidemic); in addition, donors who are in the “seronegative window” period are very dangerous. The detection of HIV among pregnant women has also increased sharply in recent years.

Main epidemiological features. The world is currently experiencing an HIV pandemic. If in the first years of the onset of the disease greatest number cases were registered in the United States, the infection is now most widespread among the population of African countries, Latin America, South-East Asia. In a number of countries in Central and Southern Africa, up to 15-20% of the adult population is infected with HIV. In Eastern European countries, including Ukraine, in recent years there has been an intensive increase in the infection rate of the population. The distribution of morbidity across the country is uneven. Large cities are the most affected.

The spread of HIV infection is associated mainly with unprotected sexual intercourse, the use of virus-contaminated syringes, needles and other medical and paramedical instruments, transmission of the virus from an infected mother to her child during childbirth or breastfeeding. In developed countries, mandatory testing of donated blood has greatly reduced the possibility of transmission of the virus through its use.

Timely initiation of treatment with antiretroviral drugs (HAART) stops the progression of HIV infection and reduces the risk of developing AIDS to 0.8-1.7%. However, antiretroviral drugs are widely available only in developed and some developing (Brazil) countries due to their high cost.

According to the Joint United Nations Program on HIV/AIDS (UNAIDS) and World Organization According to the WHO, from 1981 to 2006, 25 million people died from diseases associated with HIV infection and AIDS. Thus, the HIV pandemic is one of the most destructive epidemics in human history. In 2006 alone, HIV infection caused the death of approximately 2.9 million people. By the beginning of 2007, about 40 million people worldwide (0.66% of the world's population) were HIV carriers. Two thirds of the total number of people living with HIV live in sub-Saharan Africa. In the countries hardest hit by the HIV and AIDS pandemic, the epidemic is hampering economic growth and increasing poverty.

What causes HIV infection

HIV- AIDS virus, disease-causing- HIV infection, the last stage of which is known as acquired immunodeficiency syndrome (AIDS) - in contrast to congenital immunodeficiency.

Human immunodeficiency virus belongs to the family retroviruses(Retroviridae), genus of lentiviruses (Lentivirus). The name Lentivirus comes from the Latin word lente, meaning slow. This name reflects one of the features of viruses of this group, namely, the slow and unequal speed of development infectious process in the macroorganism. Lentiviruses also have a long incubation period.

The human immunodeficiency virus is characterized by a high frequency of genetic changes that occur during the process of self-reproduction. The error rate in HIV is 10−3 - 10−4 errors/(genome * replication cycle), which is several orders of magnitude higher than the same value in eukaryotes. The HIV genome is approximately 104 nucleotides in length. It follows from this that almost every virus differs by at least one nucleotide from its predecessor. In nature, HIV exists in the form of many quasi-species, while being one taxonomic unit. In the process of researching HIV, varieties were nevertheless discovered that differed significantly from each other in several ways, in particular, different genome structures. Varieties of HIV are designated by Arabic numerals. Today, HIV-1, HIV-2, HIV-3, HIV-4 are known.

. HIV-1- the first representative of the group, opened in 1983. Is the most common form.
. HIV-2- a type of human immunodeficiency virus identified in 1986. Compared to HIV-1, HIV-2 has been studied to a much lesser extent. HIV-2 differs from HIV-1 in genome structure. HIV-2 is known to be less pathogenic and less likely to be transmitted than HIV-1. It has been noted that people infected with HIV-2 have weak immunity to HIV-1.
. HIV-3- a rare variety, the discovery of which was reported in 1988. The discovered virus did not react with antibodies from other known groups, and also had significant differences in the structure of the genome. The more common name for this variant is HIV-1 subtype O.
. HIV-4- a rare type of virus discovered in 1986.

The global HIV epidemic is primarily driven by the spread of HIV-1. HIV-2 is predominantly distributed in West Africa. HIV-3 and HIV-4 do not play a significant role in the spread of the epidemic.

In the vast majority of cases, unless otherwise stated, HIV refers to HIV-1.

Structure of the HIV virion
HIV virions have the form of spherical particles, the diameter of which is about 100-120 nanometers. This is approximately 60 times less than the diameter of a red blood cell.

The capsid of the mature virion has the shape of a truncated cone. Sometimes there are "multinuclear" virions containing 2 or more nucleoids.

Mature virions contain several thousand protein molecules of various types.
Names and functions of the main structural proteins of HIV-1.

Inside the HIV capsid there is a protein-nucleic acid complex: two strands of viral RNA, viral enzymes (reverse transcriptase, protease, integrase) and p7 protein. The Nef and Vif proteins are also associated with the capsid (7-20 Vif molecules per virion). The Vpr protein was found inside the virion (and most likely outside the capsid). The capsid itself is formed by ~2,000 copies of the viral p24 protein. The stoichiometric ratio of p24:gp120 in the virion is 60-100:1, and p24:Pol is approximately 10-20:1. In addition, ~200 copies of cellular cyclophilin A, which the virus borrows from the infected cell, bind to the HIV-1 (but not HIV-2) capsid.

The HIV capsid is surrounded by a matrix shell formed by ~2,000 copies of the matrix protein p17. The matrix shell, in turn, is surrounded by a bilayer lipid membrane, which is the outer shell of the virus. It is formed by molecules captured by the virus during its budding from the cell in which it was formed. 72 glycoprotein complexes are embedded in the lipid membrane, each of which is formed by three transmembrane glycoprotein molecules (gp41 or TM), which serve as the “anchor” of the complex, and three surface glycoprotein molecules (gp120 or SU). With the help of gp120, the virus attaches to the CD4 receptor and coreceptor located on the surface of the cell membrane. gp41 and especially gp120 are being intensively studied as targets for HIV drug and vaccine development. The lipid membrane of the virus also contains cell membrane proteins, including human leukocyte antigens (HLA) classes I, II and adhesion molecules.

Pathogenesis (what happens?) during HIV infection

HIV Risk Groups
Groups increased risk:
. persons who use injection drugs and use common utensils for drug preparation (spread of the virus through a syringe needle and shared utensils for drug solutions); as well as their sexual partners.
. persons (regardless of sexual orientation) who practice unprotected anal sex (in particular, approximately 25% of cases of unprotected anal sex among seropositive gay men are so-called “barebackers” [comprising about 14% of all gay men in the studied sample] - persons who deliberately avoid using condoms , despite their awareness of the possibility of HIV infection; a small proportion among barebackers are “bug chasers” - individuals who purposefully seek to become infected with HIV and choose HIV-positive or potentially positive individuals, called “gift-givers”) as sexual partners
. persons who received a transfusion of untested donor blood;
. doctors;
. patients with other sexually transmitted diseases;
. persons associated with the sale and purchase of the human body in the field of sexual services (prostitutes and their clients)

HIV transmission
HIV can be contained in almost all biological fluids of the body. However, a sufficient amount of virus for infection is present only in blood, semen, vaginal secretions, lymph and breast milk(breast milk is dangerous only for babies - their stomach is not yet producing gastric juice, which kills HIV). Infection can occur when dangerous biological fluids enter directly into a person’s blood or lymph flow, as well as onto damaged mucous membranes (which is determined by the absorption function of the mucous membranes). If the blood of an HIV-infected person comes into contact with open wound As a rule, infection does not occur to another person from whom the blood flows.

HIV is unstable - outside the body, when the blood (sperm, lymph and vaginal secretions) dries, it dies. Infection does not occur through household means. HIV dies almost instantly at temperatures above 56 degrees Celsius.

However, when intravenous injections the probability of transmission of the virus is very high - up to 95%. Cases of HIV transmission to medical personnel through needle sticks have been reported. To reduce the likelihood of HIV transmission (to a fraction of a percent) in such cases, doctors prescribe a four-week course of highly active antiretroviral therapy. Chemoprophylaxis may also be prescribed to other people at risk of infection. Chemotherapy is prescribed no later than 72 hours after the probable entry of the virus.

Repeated use of syringes and needles by drug addicts with high probability leads to HIV transmission. To prevent this, special charity centers are being created where drug addicts can receive free clean syringes in exchange for used ones. In addition, young drug addicts are almost always sexually active and prone to unprotected sexual intercourse, which creates additional preconditions for the spread of the virus.

Data on HIV transmission through unprotected sex by various sources differ considerably. The risk of transmission depends largely on the type of contact (vaginal, anal, oral, etc.) and the role of the partner (injector/receiver).

Risk of HIV transmission (per 10,000 unprotected sexual contacts)
for the inserting partner during fellatio - 0.5
for the receiving partner during fellatio - 1
for the inserting partner during vaginal sex - 5
for the receiving partner during vaginal sex - 10
for the inserting partner during anal sex - 6.5
for the receiving partner during anal sex - 50

Protected sexual intercourse in which the condom breaks or its integrity is damaged is considered unprotected. To minimize such cases, it is necessary to follow the rules for using condoms, as well as use reliable condoms.

Vertical transmission from mother to child is also possible. With HAART prophylaxis, the risk of vertical transmission of the virus can be reduced to 1.2%.

HIV is not transmitted through
. bites of mosquitoes and other insects,
. air,
. handshake,
. kiss (any)
. dishes,
. clothes,
. use of a bathroom, toilet, swimming pool, etc.

HIV primarily infects cells of the immune system (CD4+ T lymphocytes, macrophages and dendritic cells), as well as several other types of cells. CD4+ T lymphocytes infected with HIV gradually die. Their death is due mainly to three factors
1. direct destruction of cells by the virus
2. programmed cell death
3. killing of infected cells by CD8+ T lymphocytes. Gradually, the subpopulation of CD4+ T-lymphocytes decreases, as a result of which cellular immunity decreases, and when the number of CD4+ T-lymphocytes reaches a critical level, the body becomes susceptible to opportunistic (opportunistic) infections.

Once in the human body, HIV infects CD4+ lymphocytes, macrophages and some other types of cells. Having penetrated into these types of cells, the virus begins to actively multiply in them. This ultimately leads to the destruction and death of infected cells. The presence of HIV over time causes disruption of the immune system due to its selective destruction of immunocompetent cells and suppression of their subpopulation. Viruses that leave the cell are introduced into new ones, and the cycle repeats. Gradually, the number of CD4+ lymphocytes decreases so much that the body can no longer resist pathogens of opportunistic infections, which are not dangerous or little dangerous for healthy people with a normal immune system.

The basis of HIV pathogenesis is still not very clear. Recent evidence suggests that hyperactivation of the immune system in response to infection is a major factor in the pathogenesis of HIV. One of the features of pathogenesis is the death of CD4+ T cells (T helpers), the concentration of which slowly but steadily decreases. The number of dendritic cells, professional antigen-presenting cells, which basically begin the immune response to the pathogen, also decreases, which may be even more important in terms of the consequences for the immune system strong factor rather than the death of T helper cells. The causes of dendritic cell death remain unclear.

Some reasons for the death of helpers:
1. Explosive reproduction of the virus.
2. Fusion of the membranes of infected and non-infected helpers with the formation of non-viable simplasts (helpers become sticky). Symplasts have only been detected in vitro under cell culture conditions.
3. Attack of infected cells by cytotoxic lymphocytes.
4. Adsorption of free gp120 on CD4+ uninfected helper cells with their subsequent attack of cytotoxic lymphocytes.

The main cause of T cell death during HIV infection is programmed cell death (apoptosis). Even at the AIDS stage, the level of infection of T4 cells is 1:1000, which suggests that the virus itself is not capable of killing the same number of cells that die during HIV infection. It is also impossible to explain such a massive death of T cells by the cytotoxic effect of other cells.

The main reservoir of HIV in the body is macrophages and monocytes:
1. Explosive reproduction does not occur in them.
2. Exit occurs through the Golgi complex.

Symptoms of HIV infection

Incubation period(the period of seroconversion - until the appearance of detectable antibodies to HIV) - the period from the moment of infection until the appearance of the body’s reaction in the form of clinical manifestations of “acute infection” and/or the production of antibodies. Its duration usually ranges from 3 weeks to 3 months, but in isolated cases can drag on for up to a year. During this period, HIV actively multiplies, but there are no clinical manifestations of the disease and antibodies to HIV have not yet been detected. The diagnosis of HIV infection at this stage is made on the basis of epidemiological data and must be confirmed in the laboratory by the detection of human immunodeficiency virus, its antigens, and HIV nucleic acids in the patient’s blood serum.

Stage 2. “Stage primary manifestations» . During this period, active replication of HIV in the body continues, but the body’s primary response to the introduction of this pathogen is already manifested in the form of clinical manifestations and/or the production of antibodies. The early stage of HIV infection can occur in several forms.

2A. "Asymptomatic", when there are no clinical manifestations of HIV infection or opportunistic diseases developing against the background of immunodeficiency. The body's response to the introduction of HIV is manifested only by the production of antibodies.

2B. "Acute HIV infection without secondary diseases» may manifest with a variety of clinical symptoms. Most often this is fever, rashes (urticarial, papular, petechial) on the skin and mucous membranes, swollen lymph nodes, pharyngitis. There may be an enlargement of the liver, spleen, and diarrhea. Broad plasma lymphocytes (“mononuclear cells”) can be detected in the blood of patients with acute HIV infection.

Acute clinical infection observed in 50-90% of infected individuals in the first 3 months after infection. The onset of the period of acute infection, as a rule, precedes seroconversion, i.e. the appearance of antibodies to HIV. During the acute infection stage, a transient decrease in the level of CD4 lymphocytes is often observed.

2B. "Acute HIV infection with secondary diseases". In 10-15% of cases in patients with acute HIV infection, secondary diseases appear against the background of a decrease in the level of CD4 lymphocytes and the resulting immunodeficiency of various etiologies(angina, bacterial and Pneumocystis pneumonia, candidiasis, herpetic infection, etc.).

The duration of clinical manifestations of acute HIV infection varies from several days to several months, but usually it is 2-3 weeks. In the vast majority of patients, the initial stage of HIV infection enters the latent stage.

Stage 3. “Latent”. It is characterized by a slow progression of immunodeficiency, compensated by modification of the immune response and excessive reproduction of CD4 cells. Antibodies to HIV are detected in the blood. The only clinical manifestation of the disease is an enlargement of two or more lymph nodes in at least two unrelated groups (not counting the inguinal ones).

Lymph nodes are usually elastic, painless, not fused with the surrounding tissue, and the skin over them is not changed.

The duration of the latent stage can vary from 2-3 to 20 or more years, on average 6-7 years. During this period, there is a gradual decrease in the level of CD4 lymphocytes, on average at a rate of 0.05-0.07x109/l per year.

Stage 4. “Stage of secondary diseases”. Continued replication of HIV, leading to the death of CO4 cells and depletion of their populations, leads to the development of secondary (opportunistic) diseases, infectious and/or oncological, against the background of immunodeficiency.

Depending on the severity of secondary diseases, stages 4A, 4B, 4C are distinguished.

The stages of secondary diseases include phases progression(against the background of the absence of antiretroviral therapy or against the background of antiretroviral therapy) and remission(spontaneous or against the background of antiretroviral therapy).

Stage 5. “Terminal stage”. At this stage, secondary diseases present in patients acquire an irreversible course. Even adequately conducted antiviral therapy and therapy for secondary diseases are not effective, and the patient dies within a few months. This stage is characterized by a decrease in the number of CD4 cells below 0.05x109/l.

It should be noted that the clinical course of HIV infection is highly variable. The sequence of progression of HIV infection through all stages of the disease is not required. The duration of HIV infection varies widely - from several months to 15-20 years.

In users of psychoactive substances, the course of the disease has some peculiarities. In particular, fungal and bacterial lesions skin and mucous membranes, as well as bacterial abscesses, phlegmon, pneumonia, sepsis, septic endocarditis may develop against the background normal level CD4 lymphocytes. However, the presence of these lesions contributes to a more rapid progression of HIV infection.

Peculiarities of the HIV clinic in children
The most common clinical manifestation of HIV infection in children is a delay in the rate of psychomotor and physical development.

In children, more often than in adults, recurrent bacterial infections occur, as well as interstitial lymphoid pneumonitis and hyperplasia of the pulmonary lymph nodes, and encephalopathy. Thrombocytopenia is common, clinically manifested by hemorrhagic syndrome, which can cause death in children. Anemia often develops.

HIV infection in children born to HIV-infected mothers is characterized by a more rapidly progressive course. In children infected after one year of age, the disease usually develops more slowly.

Diagnosis of HIV infection

The course of HIV infection is characterized by a long absence of significant symptoms of the disease. The diagnosis of HIV infection is made on the basis of laboratory data: when antibodies to HIV are detected in the blood (or the virus is directly detected!). Antibodies to HIV are usually not detected during the acute phase. In the first 3 months. after infection, antibodies to HIV appear in 90-95% of patients after 6 months. - for the rest 5-9%, and in more late dates- only 0.5-1%. During the AIDS stage, a significant decrease in the level of antibodies in the blood is recorded. The first weeks after infection represent the “seronegative window period,” when antibodies to HIV are not detected. That's why negative result testing for HIV during this period does not mean that a person is not infected with HIV and cannot infect others.

Virus isolation is not carried out in practice. IN practical work methods for determining antibodies to HIV are more popular. Initially, antibodies are detected by ELISA. If the ELISA result is positive, the blood serum is examined by immunoblotting. It allows you to detect specific antibodies to particles of the protein structure of HIV that have a strictly defined molecular weight. Antibodies to HIV antigens with molecular weights of 41,000, 120,000 and 160,000 are considered the most characteristic of HIV infection. When they are identified, a final diagnosis is made.

A negative immunoblotting result in the presence of clinical and epidemiological suspicions of HIV infection does not exclude the possibility of this disease and requires repetition laboratory research. This is explained, as already mentioned, by the fact that in incubation period There are no antibodies yet, but in the terminal stage, due to the depletion of the immune system, they cease to be produced. In these cases, the most promising is the polymerase chain reaction (PCR), which makes it possible to detect RNA particles of the virus.

When a diagnosis of HIV infection is made, multiple studies of the immune status are carried out over time to monitor the progression of the disease and the effectiveness of treatment.

To diagnose lesions of the oral mucosa in HIV-infected patients, a working classification approved in London in September 1992 was adopted. All lesions are divided into 3 groups:
. Group 1 - lesions clearly associated with HIV infection. This group includes the following nosological forms:
o candidiasis (erythematous, pseudomembranous, hyperplastic, atrophic);
o hairy leukoplakia;
o marginal gingivitis;
o ulcerative-necrotizing gingivitis;
o destructive periodontitis;
o Kaposi's sarcoma;
o non-Hodgkin's lymphoma.
. Group 2 - lesions less clearly associated with HIV infection:
o bacterial infections;
o diseases of the salivary glands;
o viral infections;
o thrombocytopenic purpura.
. Group 3 - lesions that may occur with HIV infection, but are not associated with it.

The most interesting and most common lesions are those belonging to group 1.

In Ukraine, when a diagnosis of HIV infection is made, the patient is given pre-test and post-test counseling and an explanation of the basic facts about the disease. The patient is invited to register with the territorial center for the prevention and control of AIDS for free dispensary observation infectious disease doctor. It is recommended to undergo tests approximately once every six months (for immune status and viral load) to monitor health status. In case of significant deterioration of these indicators, it is recommended to take antiretroviral drugs(therapy is free, available in almost all regions).

Treatment of HIV infection

To date, no treatment has been developed for HIV infection that could eliminate HIV from the body.

The modern method of treating HIV infection (the so-called highly active antiretroviral therapy) slows down and practically stops the progression of HIV infection and its transition to the AIDS stage, allowing an HIV-infected person to live a full life. If treatment is used and the effectiveness of the drugs is maintained, a person's life expectancy is not limited by HIV, but only by the natural processes of aging. However, after prolonged use of the same treatment regimen, after several years, the virus mutates, acquiring resistance to the drugs used, and to further control the progression of HIV infection, it is necessary to use new treatment regimens with other drugs. Therefore, any current treatment regimen for HIV infection sooner or later becomes ineffective. Also, in many cases, the patient cannot take individual drugs because of individual intolerance. That's why proper application therapy delays the development of AIDS indefinitely. Today, the emergence of new classes of drugs is mainly aimed at reducing the side effects of therapy, since the life expectancy of HIV positive people Those taking therapy are almost equal to the life expectancy of the HIV-negative population. During the later development of HAART (2000-2005), the survival rate of HIV-infected patients, excluding patients with hepatitis C, reaches 38.9 years (37.8 for men and 40.1 for women).

Importance is given to maintaining the health of HIV-positive people non-drug means(proper nutrition, healthy sleep, avoidance severe stress and prolonged exposure to the sun, a healthy lifestyle), as well as regular (2-4 times a year) monitoring of health status by HIV specialists.

Resistance (immunity) to HIV
Several years ago, a human genotype resistant to HIV was described. The penetration of the virus into an immune cell is associated with its interaction with a surface receptor: CCR5 protein. But deletion (loss of a gene section) of CCR5-delta32 leads to the immunity of its carrier to HIV. It is believed that this mutation arose approximately two and a half thousand years ago and eventually spread to Europe.
Now, on average, 1% of Europeans are actually resistant to HIV, 10-15% of Europeans have partial resistance to HIV.

Scientists at the University of Liverpool explain this unevenness by saying that the CCR5 mutation increases resistance to bubonic plague. Therefore, after the Black Death epidemics of 1347 (and in Scandinavia also in 1711), the share of this genotype increased.

There is a small percentage of people (about 10% of all HIV-positive people) who have the virus in their blood, but do not develop AIDS for a long time (so-called non-progressors).

It was discovered that one of the main elements of the antiviral defense of humans and other primates is the TRIM5a protein, which is capable of recognizing the capsid of viral particles and preventing the virus from multiplying in the cell. This protein in humans and other primates has differences that determine the innate resistance of chimpanzees to HIV and related viruses, and in humans - innate resistance to the PtERV1 virus.

Another important element antiviral defense - interferon-induced transmembrane protein CD317/BST-2 (bone marrow stromal antigen 2), also called “tetherin” for its ability to suppress the release of newly formed daughter virions by retaining them on the cell surface. CD317 is a type 2 transmembrane protein with an unusual topology - a transmembrane domain near the N-terminus and glycosylphosphatidylinositol (GPI) at the C-terminus; Between them is the extracellular domain. It has been shown that CD317 directly interacts with mature daughter virions, “tethering” them to the cell surface. To explain the mechanism of this “binding”, four alternative models have been proposed, according to which two CD317 molecules form a parallel homodimer; one or two homodimers bind simultaneously to one virion and cell membrane. In this case, either both membrane “anchors” (transmembrane domain and GPI) of one of the CD317 molecules, or one of them, interact with the virion membrane. The spectrum of activity of CD317 includes at least four families of viruses: retroviruses, filoviruses, arenaviruses, and herpesviruses. The activity of this cellular factor is inhibited by the proteins Vpu of HIV-1, Env of HIV-2 and SIV, Nef of SIV, the envelope glycoprotein of the Ebola virus and the K5 protein of Kaposi's sarcoma herpesvirus. A cofactor of the protein CD317 was discovered - cellular protein BCA2 (Breast cancer-associated gene 2; Rabring7, ZNF364, RNF115) - E3 ubiquitin ligase of the RING class. BCA2 enhances the internalization of HIV-1 virions tethered to the cell surface by the CD317 protein into CD63+ intracellular vesicles with their subsequent destruction in lysosomes.

CAML (calcium-modulated cyclophilin ligand) is another protein that, like CD317, inhibits the release of mature daughter virions from the cell and whose activity is suppressed by the HIV-1 Vpu protein. However, the mechanisms of action of CAML (a protein localized in the endoplasmic reticulum) and antagonism by Vpu are unknown.

People living with HIV
The term People Living with HIV (PLHIV) is recommended to refer to a person or group of people who are HIV-positive, as it reflects the fact that people can live with HIV for decades while leading active and productive lives. The expression “victims of AIDS” is extremely incorrect (this implies helplessness and lack of control), including incorrectly calling children with HIV “innocent victims of AIDS” (this implies that someone living with HIV is “to blame” for their HIV status or "deserved" it). The expression “AIDS patient” is only acceptable in a medical context, since PLHIV do not spend their lives in a hospital bed. The rights of HIV-infected people are no different from the rights of other categories of citizens: they also have the right to receive medical care, freedom of work, education, personal and family privacy, and so on.

Prevention of HIV infection

WHO identifies 4 main areas of activity aimed at combating the HIV epidemic and its consequences:
1. Prevention of sexual transmission of HIV, including such elements as teaching safe sexual behavior, distributing condoms, treating other STDs, teaching behavior aimed at consciously treating these diseases;
2. Prevent bloodborne transmission of HIV by providing safe blood products.
3. Prevention of perinatal transmission of HIV by disseminating information on the prevention of HIV transmission by providing medical care, including counseling women infected with HIV and chemoprophylaxis;
4. Organization of medical care and social support HIV patients, their families and others.

Sexual transmission of HIV can be interrupted by teaching the population about safe sexual behavior, and intra-hospital transmission can be interrupted by observing the anti-epidemic regime. Prevention includes proper sex education of the population, prevention of promiscuity, propaganda safe sex(use of condoms). Special direction - preventative work among drug addicts. Since it is easier to prevent HIV infection among drug addicts than to rid them of drug addiction, it is necessary to explain how to prevent infection during parenteral drug administration. Reducing drug addiction and prostitution is also part of the HIV prevention system.

To prevent the transmission of HIV through blood, blood, sperm, and organ donors are examined. To prevent infection of children, pregnant women should be tested for HIV. Patients with STDs, homosexuals, drug addicts, and prostitutes are examined mainly for surveillance purposes.

The anti-epidemic regime in hospitals is the same as in viral hepatitis B, and includes ensuring the safety of medical procedures, donated blood, medical immunobiological preparations, biological fluids, organs and tissues. Prevention of HIV infection medical personnel comes down mainly to compliance with the rules for working with cutting and piercing tools. In case of contact with HIV-infected blood, it is necessary to treat the skin with 70% alcohol, wash with soap and water and re-treat with 70% alcohol. As a preventive measure, it is recommended to take azidothymidine for 1 month. The person exposed to the threat of infection is under the supervision of a specialist for 1 year. Means of active prevention have not yet been developed.

31.07.2018

In St. Petersburg, the AIDS Center, in partnership with the City Center for the Treatment of Hemophilia and with the support of the Hemophilia Society of St. Petersburg, launched a pilot information and diagnostic project for patients with hemophilia infected with hepatitis C.

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Despite the fact that HIV infection has been spreading throughout the globe for more than 30 years and the flow of information about it is quite extensive, not everyone knows how HIV infection is transmitted and how HIV infection occurs.

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More than 40 million people on Earth are affected by HIV, and the rate of infection is not decreasing at all. Therefore, it is impossible to ignore and remain indifferent to this problem. In the current situation, everyone should clearly know how one can become infected with HIV in order to protect themselves and their loved ones.

Features of HIV

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HIV is a retrovirus that enters the human body and does not manifest itself in any way; the infected person does not even suspect it. Once the virus enters the body, it can behave differently. In 70% of infected people (about a month later), an acute phase of HIV infection develops, which manifests itself with symptoms reminiscent of mononucleosis or a common acute respiratory infection, and therefore is not diagnosed.

It would be possible to diagnose the disease using PCR, but this rather expensive test would need to be prescribed to every patient with acute respiratory infections. The patient recovers fairly quickly and feels absolutely normal, unaware of his infection. This phase is called asymptomatic.

Antibodies to the virus do not begin to be produced immediately after the infection enters the body. Sometimes it takes 3, and sometimes 6 months until specific antibodies confirming the disease begin to be detected in the blood. The maximum duration of this period, when the virus is already in the body, but there are no antibodies yet, is 12 months. This is called the seroconversion period or seronegative window.

This period imaginary well-being may last 10 or more years. But an infected person can infect others in various ways transmission of HIV infection.

To do this, it is only necessary to achieve a certain concentration of the virus in the infected person’s body. And since the virus multiplies at tremendous speed, soon all the biological fluids of the infected person contain HIV, only in different concentrations.

Fortunately, the virus is not resistant outside the human body. It dies when heated to 57 0 C in half an hour, and when boiled in the first minute. Detrimental effect Alcohol, acetone, and conventional disinfectants also have properties. On the surface of intact skin, the virus is destroyed by enzymes and other bacteria.

The difficulty of fighting HIV is that it is very mutant, even in the same organism it has different structural variants. Therefore, a vaccine against HIV has not yet been created. Once HIV enters the body, it infects immune cells, making a person defenseless against any type of infection.

Ways of spreading the disease

How HIV infection occurs is a concern for many people who live or work near infected people. Experts have proven that the concentration of the virus sufficient to infect another person is present in the blood, semen and vaginal discharge, in breast milk. The modes of transmission of HIV are associated with these biological substances.

There are 3 ways of transmitting HIV:

1. The most common way of contracting HIV is sexual path. Infection occurs through unprotected sexual contact. Moreover, the variety of ways of transmitting HIV infection is striking - through homosexual contact, vaginal, oral, anal sex.

Numerous relationships with prostitutes, homosexual relationships are the most dangerous. During anal sex, microtraumatic injuries occur in the rectum, which increase the risk of infection. Women who have sexual contact with an HIV-infected partner are more vulnerable: they become infected 3 times more. more often than a man from an infected partner.

The presence of cervical erosion, inflammatory process in the genitals increase the possibility of infection. There are about 30 known sexually transmitted diseases or STDs. Many of them involve an inflammatory process, so STDs significantly increase the likelihood of HIV transmission. The possibility of infection increases for both partners during sex during menstruation.

With oral sexual contact, the likelihood of infection is somewhat less, but it does exist. Many people are interested in: is it possible to transmit HIV through one sexual contact? Unfortunately, the infection can be transmitted in this case too. That is why one of the indications for emergency drug prevention of infection is the rape of a woman.

1. HIV is also easily transmitted through blood. This route is called parenteral. With this method of infection, transmission of the virus is possible through blood transfusion, organ or tissue transplantation, or manipulation of non-sterile instruments (including syringes).

For infection, it is enough for one ten-thousandth of a milliliter of blood to enter another body - such an amount is invisible to the human eye. If the slightest particle of blood from an infected person enters the body of a healthy person, then the probability of infection is almost 100%.

Such situations can arise when applying a tattoo, ear piercing, piercing not in a specialized salon, but random people. Infection can also occur when performing a manicure/pedicure with untreated instruments. Washing with water is not enough to remove residual blood. Instruments must undergo complete processing (disinfection and sterilization).

Infection through donated blood is unlikely, since the collected blood is rechecked not only after collection, but also donors are additionally examined after 6 months in order to exclude the period of seroconversion at the time of blood donation. The collected blood remains in the blood bank of the transfusion stations all this time and is issued only after rechecking.

IN dental offices and clinics, in the surgical service, instruments are, in addition to disinfection, sterilized in dry-heat ovens or autoclaves. Therefore, the risk of infection by them in medical institutions minimized.

Most actual way HIV infection through blood is for consumers narcotic drugs by injection. Many of them try to reassure themselves about the issue of HIV infection by using disposable syringes. However, when purchasing a dose from a drug distributor, they cannot be sure that the disposable syringe they bring does not contain a previously infected substance.

Sometimes drug users use a shared syringe, changing only the needles, although with intravenous injections, blood necessarily enters the syringe and infects it.

In everyday life, infection can occur when using someone else's or a shared razor. Family members of an infected person can also become infected from him when providing assistance without rubber gloves in the event of an injury or cut.

1. Vertical HIV infection is the transmission of the virus from an infected mother to her child. How is HIV transmitted in this case? There can be different ways for a child to become infected with HIV:

• firstly, the virus is able to overcome the placental barrier and then infection of the fetus occurs in utero;
• secondly, infection can occur directly during childbirth;
• thirdly, the mother can infect the child through breast milk.

You can prevent your baby from getting infected with a free preventive treatment antiviral drugs, if the woman promptly contacted the antenatal clinic during pregnancy and underwent all the necessary tests.

To reduce the risk of infection of the child, in some cases, delivery is performed by caesarean section. The baby also receives for 28 days antiviral drugs, issued free of charge.

After birth, it is recommended to feed the baby with formula milk. There are, however, cases when tests during pregnancy were negative, since there was a period of seronegative window (seroconversion). In this case, the child will receive the virus through milk during breastfeeding.

When infection does not occur

Despite the fact that the virus is present in any body fluid, its concentration in them is different. Thus, tears, sweat, saliva, feces and urine do not play an epidemiological role, since they do not lead to infection of another person. It would take liters of tears or sweat, for example, so that if they come into contact with the damaged skin of a healthy person, they could transmit the virus. True, infection is possible through kissing if blood gets into the saliva due to bleeding gums.

Infection does not threaten in the following cases:

1. Fortunately, HIV is not an airborne virus. Staying in the same room with an infected person is not dangerous.
2. It is not dangerous to use the same toilet, bathtub, shared utensils or towels.
3. You can't get infected in the pool.
4. You can safely use one phone and not be afraid of shaking hands with an infected person.
5. HIV is not transmitted by animals or insect bites.
6. Water and food routes of infection are also excluded.

Risk group

Considering the possible ways of spreading the disease, doctors identify a risk group, which includes:

• injection drug users;
• persons with non-traditional sexual orientation(homosexuals);
• persons engaged in prostitution;
• persons with promiscuous sex, practicing unprotected sex (without a condom);
• patients with sexually transmitted diseases;
• blood product recipients;
• children born from an HIV-positive mother;
• health workers providing care to patients with HIV.

HIV infection is a special disease that may not have clinical manifestations for a number of years, but sooner or later leads to a state of immunodeficiency, that is, to AIDS. At this stage, it is quite difficult to fight the disease; a person can die from any common infection. Therefore, everyone should clearly know how HIV is transmitted and protect themselves as much as possible.