is an abbreviation for the term Human Immunodeficiency Virus. The virus infects the immune system of the human body, introducing HIV infection into it. Developing, this infection manifests itself with various symptoms, combined in the “acquired immunodeficiency syndrome” or AIDS.
Fundamental differences between AIDS and HIV infection:
AIDS (AIDS) is a state of immunity in which the body is practically defenseless against the harmful effects of the environment and the development of oncological processes. Any infection that is harmless to a healthy person, in an AIDS patient, transforms into a serious illness with subsequent death from complications, inflammation of the brain,;
HIV infection is a slowly developing viral infection that has a long-term course. All currently known methods of treating HIV infection do not lead to a complete cure. The disease affects the immune system, which protects the human body from the negative effects of the external environment. The virus, having entered the body from a carrier of the disease, may not manifest itself in any way for a long time, but for several years it consistently destroys the immune system.
Facts, history and statistics of HIV infection
The danger and pace of the spread of HIV infection are so great that it has been called the "plague of the 20th century." Every day, about 5,000 people die from the consequences of this disease in the world. Until recently, nothing was known about this deadly disease to mankind. Only in the 70s of the last century were the first cases of the disease with symptoms similar to AIDS registered.
The first facts of official recognition of the existence of HIV infection:
1981 - publication of scientific articles describing the unusual course of pneumocystis pneumonia caused by a yeast-like fungus and malignant skin lesions (Kaposi's sarcoma) in men with a non-traditional sexual orientation;
July 1982 - the emergence of the term "AIDS";
1983 - the simultaneous discovery of the virus in two independent laboratories: at the French Institute. Louis Pasteur (research leader - Luc Montagnier) and at the US National Cancer Institute (research leader - Robert Gallo);
1985 - development of a method for enzyme immunoassay, which determines the presence of antibodies to the immunodeficiency virus in the blood;
1987 - the first person infected with HIV appeared in the USSR. The man worked as a translator in African countries, had homosexual relationships;
About the history of HIV
There are several hypotheses for the emergence of the human immunodeficiency virus. One of them is infection from great apes. From the blood of chimpanzees living in Central Africa, researchers have isolated a virus that can cause in the human body. It is possible that a person could become infected by a monkey bite or by contact with raw animal meat.
This type of virus is not capable of causing significant harm to the human body, since the immune defense is able to destroy it within 7 days. In order for it to acquire the properties characteristic of HIV infection, it is required to transfer it to another person within this short period. In this case, mutations occur with the virus, and it acquires characteristics that are dangerous for humans.
In addition to this hypothesis, it is suggested that AIDS existed long before its official discovery by science, affecting the indigenous people of Central Africa. Its rapid spread across countries and continents began due to active migration in the twentieth century.
Statistical data on the number of HIV-infected people
Ukraine - about 410 thousand,
Kazakhstan - about 20 thousand,
Belarus - more than 30 thousand,
Moldova - 17800,
Georgia - 6600,
Armenia - 4000,
Tajikistan - 16400,
Azerbaijan - 4171,
Kyrgyzstan - about 10 thousand,
Turkmenistan - official authorities claim that there are isolated cases of HIV infection in the country,
Uzbekistan - about 33 thousand.
Worldwide, as of December 1, 2016, the number of infected people was 36.7 million.
In Russia, as of December 2016, there were about 800,000 people, with 90,000 identified in 2015. In the same year, more than 25,000 people died of AIDS in Russia, and over 200,000 over the entire observation period since 1987.
For the CIS countries (data for 2015):
Since the statistics record only officially detected cases, the real picture is much worse. A huge number of people do not even suspect that they are HIV-infected, and continue to infect others.
Since the beginning of the spread of the infection, the number of deaths from AIDS worldwide has exceeded 36 million. This epidemic is being contained and even reduced in annual death rates by HAART (highly active antiretroviral therapy).
Famous people who died as a result of AIDS:
Rudolf Nureyev - the famous ballet soloist of world renown, passed away in 1993;
Gia Karanji - American top model, was addicted to hard drugs, died in 1986;
Michael Wastphal, a promising tennis player, passed away at the age of 26.
Freddie Mercury is a legend of rock music, the lead singer of the band Queen. Passed away in 1991;
Ryan White is the first child to be infected with AIDS. He gained fame thanks to the fight for the rights of HIV-infected people to a normal life, which he led with the support of his mother. He became infected at the age of 13 during a blood transfusion, which he needed due to a hereditary disease - hemophilia. He passed away at the age of 18, in 1990, leaving a memory of himself as a person who proved that HIV-infected people do not pose a threat to society if precautions are taken.
Despite close attention to the nature of the virus and the recognition of its exceptional danger to humans, scientists have made little progress in the search for an effective cure for AIDS. A feature of HIV is that it mutates extremely quickly, changing at a rate of 1000 mutations per gene. For comparison, influenza virus mutations occur 30 times less frequently. The rapid modification of HIV has affected the fact that a vaccine against this infection has not yet been created, there is no one hundred percent effective drug for the treatment of AIDS. Additional problems create a variety of strains of the virus.
The structure of the human immunodeficiency virus
Main types of HIV:
HIV-1 or HIV-1 - causes typical symptoms, is very aggressive, is the main causative agent of the disease. Opened in 1983, found in Central Africa, Asia and Western Europe, North and South America.
HIV-2 or HIV-2 - the symptoms of HIV are not as intense, it is considered a less aggressive strain of HIV. Opened in 1986, found in Germany, France, Portugal and West Africa.
HIV-2 or HIV-2 are extremely rare.
The virus has the shape of a sphere measuring 100-120 nanometers. Its dense shell consists of a double layer of lipids, has peculiar “spikes”, and a p-24-capsid protein layer is enclosed under the fat-like top layer.
Elements of the virus under the capsule:
Ribonucleic acid (RNA), which stores genetic information;
Virus enzymes: integrase, protease, reverse transcriptase;
The human immunodeficiency virus belongs to the family of retroviruses that do not synthesize protein and do not have a cellular structure. The reproduction of such a virus occurs extremely slowly, exclusively in the cells of the human body.
Thanks to one of their enzymes, reverse transcriptase, retroviruses convert their own RNA molecule into DNA. Then they introduce this custodian and transmitter of genetic information into the cells of the organism in which they are located.
Resistance to the external environment:
Outside the carrier dies within a few minutes;
At t above 56 ° C, it dies in half an hour;
When boiled, it dies instantly;
It dies very quickly under the influence of ether, acetone, 5% hydrogen peroxide solution, 70% alcohol, chloramine solution;
In the dried state at t + 22 ° C, it lasts from 4 to 6 days;
Heroin solution lasts up to 3 weeks;
In the cavity of a medical needle, it remains viable for several days.
The virus is not affected by ultraviolet and ionizing radiation; after freezing, it remains active.
Features of the life cycle of the virus - prefers to introduce cells of the immune system:
Macrophages - absorbers and utilizers of pathogenic viruses and microorganisms;
T-lymphocytes (helpers) - stimulants of the immune system, producing substances to counteract foreign cells: viruses, fungi, microbes, allergens;
Monocytes are cells that digest pathogenic cells after their death;
Cells of the nervous system with special receptors - CD4 cells.
Phases of the HIV life cycle (on the example of a T-lymphocyte)
The virus enters the body, finds a T-lymphocyte and binds on its surface with special receptors - CD4 cells. Having got into the cage with their help, he throws off his protective outer shell;
With the help of the reverse transcriptase enzyme, one strand of DNA is synthesized on the RNA template of the virus, then it is completed into a 2-stranded molecule;
With the help of the integrase enzyme, the DNA molecule is introduced into the nucleus of the T-lymphocyte and integrated into its DNA;
A molecule can remain dormant for several months or even years. A test for antibodies to the virus at this stage can already detect its presence in the body;
An infection of any etiology can provoke further reproduction of the virus by transferring information from a copy of the DNA to the RNA template of the virus;
With the help of cell ribosomes, HIV proteins are synthesized on viral RNA;
New viruses are assembled from the RNA template and new synthesized proteins. Leaving the cell, they destroy it;
New viruses find themselves new cells for introduction (other T-lymphocytes), the cycle repeats.
Without countermeasures in the form of treatment, the human immunodeficiency virus reproduces its own kind at a rate of 10 to 100 billion per day.
Ways and risks of HIV infection
No one is safe from HIV infection, a person of any gender, age, social status, sexual orientation and financial situation is a target for the virus. The source of its spread is an HIV-infected person, regardless of the stage of development of the disease.
The medium that transmits the virus is blood, semen, breast milk, vaginal discharge, cerebrospinal fluid, that is, the biological fluids of the human body. It is impossible to get HIV by airborne droplets. The infectious dose is at least 10 thousand viral particles that enter the bloodstream.
Ways of getting HIV infection:
Heterosexual contacts that are not protected. Vaginal sex is the most common way of transmission of the virus from person to person (70-80% of the total number of infected people worldwide). In Russia, 40% of those infected with HIV received the virus in this way.
A single sexual contact with ejaculation carries a minimal risk. For a passive partner, it is 0.1-0.32%, for an active one - from 0.01 to 0.1%. These values increase if one of the partners has a sexually transmitted disease (chlamydia, gonorrhea, syphilis, trichomoniasis, etc.). In the focus of inflammation there is always a high concentration of cells of the immune system, for example, T-lymphocytes. The human immunodeficiency virus will definitely take advantage of such a situation.
With sexual infections, the mucous membrane of the reproductive organs is often prone to inflammation and microtrauma in the form of sores, cracks and erosions. This is another factor in the increased risk of contracting HIV.
Regularly repeated sexual contacts significantly increase the risk of infection. A man infected with HIV within 3 years in 45-50% of cases necessarily infects his permanent partner, and a woman with HIV infection infects a permanent partner in 35-40% of cases. For women, this risk is higher because infected semen has longer contact with the vaginal mucosa and covers a larger area.
intravenous drug use. For Russia, this route of infection is typical in 57.9% of cases, global statistics are 5-10%. Infection of drug addicts occurs through common needles for injecting drugs that are not subject to sterilization, possibly through a common container for preparing an intravenous solution. It is this route of infection that is typical for 30-35% of cases. The remaining indicators are related to infection due to promiscuity of persons addicted to intravenous drugs.
Unprotected anal sex. The route of infection is characteristic of both homosexual and heterosexual contacts. Even with a single act, the risk of infection for a passive partner is 0.8-3.2%, and for an active one - 0.06%. This difference is explained by the vulnerability and good blood supply to the rectum.
Unprotected oral sex. With a single contact that ended in ejaculation, the risk of infection for a passive partner is 0.03-0.4%, and for an active one it is practically safe. However, such contact becomes more dangerous if there are defects in the mucous membrane such as “jam”, sores, and wounds in the oral cavity.
Transmission of the virus to a child from an HIV-infected mother. In 25-35% of cases, children become infected during childbirth through contact with fragments of the placenta, as well as during breastfeeding. A healthy woman can get the virus from an infected baby while breastfeeding if the baby has damage to the oral mucosa, and the woman has cracked nipples.
Accidental injuries during medical manipulations, subcutaneous and intramuscular injections. The probability of infection is 0.2-1%, provided that there was contact with any biological fluid of an infected person.
Blood transfusion and organ transplant. The probability of infection from an infected donor is almost 100%.
The higher the immune status of a healthy person, the lower the risk of getting an infection when in contact with an HIV-infected patient. Conversely, weak immunity will lead to an increased risk of infection and a severe course of the resulting disease. A high viral load in a person who has HIV in the body increases his risk as a carrier of the disease several times.
HIV symptoms in men and women
It is almost impossible to identify the specific symptoms of HIV infection, as they are masked as manifestations of other diseases. And the first sign and symptom of HIV in men and women as such does not exist at all. In addition, HIV infection has a different course depending on the state of the immune system of patients.
Stages of HIV infection in accordance with the clinical classification of V.I. Pokrovsky, adopted in Russia:
Symptoms of HIV at stage 1
Incubation lasts from the moment of infection to 1-1.5 months (in some cases up to a year), characterized by active reproduction of the virus.
The first symptoms of HIV, both in men and women, are absent, testing does not detect antibodies to the virus. Suspicion of the onset of infection exists in the presence of a dangerous situation: unprotected sex, blood transfusion.
HIV symptoms in stage 2
There is an immune response to the invasion and reproduction of the virus. The first symptoms of HIV infection may appear before seroconversion. The second stage lasts from 2-3 weeks to several months.
There are 3 options for the course of stage 2:
Symptoms of HIV in stage 4
Kaposi's sarcoma is a malignant tumor of the skin;
Symptoms in Stage 4B
Stage 4B develops 10-12 years after infection. It is characterized by the appearance of diseases that threaten life. The course of infections is extremely severe, they are difficult to treat. However, this stage is also reversible with HAART.
Characteristic symptoms of HIV and disease at stage 4B:
Extreme exhaustion, accompanied by weakness, patients are forced to spend most of the time in bed;
Pneumocystis pneumonia is a characteristic symptom of HIV infection, caused by a fungus;
recurrent herpes;
Fungal infection of the skin and internal organs: esophagus, respiratory organs;
Cryptococcal meningitis caused by a soil fungus does not occur in a healthy person;
Mycobacterioses, which target the gastrointestinal tract, brain, lungs, central nervous system, are characteristic of HIV infection;
Diseases of the central nervous system (clumsiness in movements, dementia, absent-mindedness, impaired memory, intelligence) are the result of complications and the effect of the virus on the cells of the nervous system;
Damage to the heart and kidneys;
Oncological diseases.
Symptoms of HIV at stage 5
The terminal stage develops as the patient's condition worsens. Symptoms of stage 5 HIV progress due to ineffective treatment of secondary infections. Frequent deaths within a few months.
All stages and manifestations of HIV infection are given for the average case. Not all infected people pass through them sequentially, they may skip some stages or linger on some of them. The duration of the disease depends on the state of the patient's immune system and the type of virus, it can last from 7-9 months to 20 years.
This Pokrovsky classification is not the only one; there is a less structured WHO classification. However, experts use a more detailed structure.
Features of HIV symptoms in men, women and children
In men, the symptoms do not have any specificity. Women are noted with cycle disorders, an increased risk of malignant degeneration of the tissues of the cervix. Inflammatory diseases of the pelvic organs in women infected with HIV occur 3 times more often, have a more severe course.
Children infected with HIV are mentally and physically delayed compared to their peers.
An effective drug for a complete cure for this disease has not yet been created. However, there are many effective drugs that reduce the viral load and improve the quality of life of patients with HIV. With strict adherence to the recommendations for their intake, an increase in CD4 cells is noted and a minimum HIV titer is recorded with the most sensitive diagnostic methods.
This result is easy to achieve with the developed self-discipline of the patient: timely and continuous medication, observing the correct dosage.
The main directions of therapy:
Maintaining the quality of life of HIV-infected people;
Prevention and temporary delay of conditions that threaten the life of the patient;
Achieving remission with HAART and prevention of secondary infections;
Practical and psychological support for patients;
Providing free medicines.
Principles of prescribing HAART according to the stages of the disease:
At the first stage, treatment is not carried out; in case of contact with HIV, chemoprophylaxis is carried out;
In the second stage, treatment is carried out depending on the level of CD4-lymphocytes present;
At the third stage, HAART is prescribed if the patient actively desires or if the RNA level exceeds 10,000 copies and the level of CD4-lymphocytes is less than 200 CD4/mm3;
At the fourth stage, treatment is prescribed when the level of RNA is more than 100 thousand copies and the level of CD4-lymphocytes is less than 200 CD4/mm3;
The fifth stage is always accompanied by treatment.
The current standards of HIV care may change in line with recent research showing that early HAART initiation leads to better outcomes.
At the moment, therapy includes a combination of the following groups of drugs:
HIV protease inhibitors,
Nucleoside inhibitors of HIV reverse transcriptase,
Non-nucleoside inhibitors of HIV reverse transcriptase.
There is evidence of the development of a new drug for the treatment of HIV infection - Quad, which is more effective and has fewer side effects. The drug is taken once a day and replaces several drugs.
HIV prevention measures
It has become an axiom that it is easier to prevent a disease than to treat it later. This is true for the prevention of AIDS and HIV infection.
Hetero- and homosexual relationships:
Have one HIV-negative sexual partner;
Protect sexual intercourse with a reliable condom (latex with standard lubrication).
Even such a condom cannot give a 100% guarantee of safe intercourse, since the virus can penetrate through the pores of the latex. In addition, when rubbed, they can expand. You can significantly reduce the risk of infection with the correct use of a condom: choosing the appropriate size, putting it on before intercourse, avoiding a gap (removing air between the latex layer and the genitals). Condoms made from other materials are completely unreliable.
Intravenous injections for drug addiction and the inability to stop taking drugs:
Use for injections of disposable spitz once;
Preparation of a solution for intravenous injection in an individual container.
Reducing the risk of conceiving a fetus in an HIV-infected woman:
Using the method of self insemination (with a partner who does not have HIV);
Semen disinfection for further fertilization (with an HIV-infected partner);
IVF (in vitro fertilization).
Before conception, a woman who decides to become a mother with a positive HIV status is informed about the possible risk to her health and the health of the fetus. Further, STDs, chronic pathologies are necessarily treated, factors that reduce the protective properties of the placenta are excluded: smoking, alcoholism, drug addiction. The key to successful bearing and birth of a healthy child is the exact implementation of the recommendations of doctors, protecting yourself from infection, diagnosing the viral load and the level of CD4 cells.
The pregnant woman is taking the following medications:
HAART for the treatment and prevention of infection;
Iron preparations;
Multivitamins.
Pregnancy with HIV infection is resolved by caesarean section in order to exclude contact of the child with cervical mucus and placenta containing a large number of viruses.
Protection of medical personnel from infection:
Use of personal protective equipment (mask, goggles, gloves, clothing);
Disposal of used needles in special containers with puncture protection;
In case of accidental contact with infected biological fluids - HAART chemoprophylaxis;
In case of accidental contact of damaged skin with a presumably infected environment - do not stop bleeding from a puncture or cut for several seconds, treat with alcohol with a strength of at least 70%;
In case of accidental contact of intact skin with the biological environment - wash with soap under running water, wipe with 70% alcohol;
If swallowed, rinse with 70% alcohol;
In case of contact with eyes, rinse with running water;
In case of contact with shoes or clothes, wipe with a disinfectant solution or soak in it, wipe the skin under clothing with alcohol;
In case of contact with tiled floors and walls - pour disinfectant for half an hour, wipe.
HIV: answers to questions
Infection occurs from an HIV-infected patient, regardless of the stage of the disease. A healthy person becomes infected when a sufficient dose of the virus enters his bloodstream to cause infection.
How the virus is transmitted:
Heterosexual and homosexual unprotected intercourse with an HIV-infected partner. Most often, infection occurs in those who have promiscuous sex. The risk is increased with anal sex, regardless of the orientation of sexual partners;
In drug addicts with intravenous drug injections with non-sterile syringes, using one container for preparing a solution for injection;
Children from HIV-infected mothers during pregnancy, during childbirth, while breastfeeding;
During medical manipulations, injections associated with contact with infected biological fluids;
In blood transfusion and donor organ transplantation, the situation may arise with a false negative result in the donor during the “window period”.
According to the law on the protection of the rights of HIV-infected people, information about their status must be kept secret and cannot be transferred to third parties. Such a measure allows not to be afraid of discrimination in case of a positive result.
An HIV blood test is carried out free of charge in two ways:
Anonymously. The test is assigned a number to obtain the result, and the name of the person taking the test remains secret;
Confidentially. Laboratory staff maintain medical secrecy, although they know the name and surname of the person being tested for HIV.
Testing is carried out:
At the regional AIDS prevention center;
In the polyclinic at the place of residence in the anonymous testing room,
In a private medical center with special facilities (for a fee).
Before and after testing, psychological support and counseling are provided for a person who decides to undergo an HIV diagnosis. Test results can be obtained on the same day, or 2-3 to 14 days after diagnosis.
What to do if the HIV test is positive?
If the result is positive, an anonymous conversation is held with the doctor about the course of the disease, the necessary additional studies and treatment methods, about possible risks and complications. Such advice can be obtained from an infectious disease doctor at the place of residence or at the regional center for the prevention and control of AIDS.
Required research:
To determine the level of CD4 cells;
The presence or absence of viral hepatitis;
on viral load;
For the p-24 capsid antigen.
According to the indications, studies of the general immune status, STD pathogens, markers of malignant neoplasms, CT, etc. are carried out.
Airborne (when sneezing and coughing);
When using shared cutlery;
In the bath, sauna, steam room;
When swimming in a pool, a common pond;
When bitten by an animal or insect;
During the medical examination;
In public places, in transport;
When using one toilet;
Through a kiss or a handshake.
Patients with viral hepatitis, for example, are much more dangerous to others than people infected with HIV.
These are people who deny the existence of the human immunodeficiency virus.
Their beliefs are based on the following arguments:
The virus has not been identified and not cultivated outside the human body. No one has seen HIV, so far only a set of proteins has been isolated, it is arguable that they belong to the same virus. In fact, there are a large number of photographs of the virus taken using an electron microscope;
Patients die more frequently from antiviral therapy for AIDS than without treatment. Indeed, the first drugs for the treatment of HIV infection had many side effects. But modern drugs are effective and safe, besides, new, even more effective developments are constantly appearing;
AIDS is a conspiracy of pharmaceutical concerns. If this were true, then companies would offer a remedy for the disease, which is not available until today;
AIDS is an autoimmune disease that is not viral in nature. Allegedly, immunodeficiency is caused by toxic poisoning, stress, radiation and other causes. The argument against this statement is that after the start of taking HAART, patients improve. Such statements disorientate patients, some of them refuse treatment. In fact, special therapy started on time allows HIV-infected people to lead a normal life, have healthy children, and work. At the same time, the course of the disease slows down, life expectancy is preserved. All this is possible with timely diagnosis and timely initiation of HAART.
About the doctor: From 2010 to 2016 practicing physician of the therapeutic hospital of the central medical unit No. 21, the city of Elektrostal. Since 2016, she has been working at the diagnostic center No. 3.
However, antiretroviral drugs are widely available only in developed and some developing (Brazil) countries.
The Joint United Nations Program on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that 25 million people have died from diseases associated with HIV infection and AIDS since to 25 million. Thus, the HIV pandemic is one of the most devastating epidemics in human history. In 2006 alone, HIV infection caused about 2.9 million deaths. By the beginning of 2007, about 40 million people worldwide (0.66% of the world's population) were carriers of HIV. Two-thirds of the total number of people living with HIV live in sub-Saharan Africa. In countries hardest hit by the HIV and AIDS pandemic, the epidemic hinders economic growth and increases poverty
Discovery history
Transmission electron microscope image of viruses. The structure of the virus is visible, inside of which there is a cone-shaped nucleus.
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 on unusual cases of pneumocystis pneumonia and Kaposi's sarcoma in homosexual men, published in. In July, the term AIDS was proposed for the first time to refer to a new disease. In September of that year, based on a series of opportunistic infections diagnosed in (1) gay men, (2) drug addicts, (3) hemophilia A patients, and (4) Haitians, AIDS was first fully defined as a disease. Between 1981 and 1984, several papers were published linking the danger of developing AIDS with anal sex or with the influence of drugs. In parallel, work was underway on the hypothesis of the possible infectious nature of AIDS. The human immunodeficiency virus was independently discovered in 1983 in two laboratories:
- in France under the direction of Luc Montagnier (fr. Luc Montagnier).
- at the National Cancer Institute in the United States under the direction of Robert Gallo (Eng. Robert C. Gallo).
The results of studies in which a new retrovirus was isolated from patient tissues for the first time were published May 20 in the journal Science. These articles reported the discovery of a new virus belonging to the HTLV group of viruses. The researchers hypothesized that the viruses they isolated could cause AIDS.
In addition, the scientists reported the detection of antibodies to the virus, the identification of previously described in other viruses and previously unknown HTLV-III antigens, and the observation of virus replication in a population of lymphocytes.
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".
Biology of HIV
Once in the human body, HIV infects CD4+ lymphocytes, macrophages, and some other cell types. 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 a violation 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 that are not dangerous or slightly dangerous for healthy people with a normal immune system.
Classification
The human immunodeficiency virus belongs to the family of retroviruses ( Retroviridae), a genus of lentiviruses ( Lentivirus). Name Lentivirus comes from the Latin word lente- slow. This name reflects one of the features of the viruses of this group, namely, the slow and uneven rate of development of the infectious process in the macroorganism. Lentiviruses also have a long incubation period.
Related viruses
in the genus Lentivirus the following types are distinguished (according to data for 2008).
| Abbreviation | English name | Russian name |
|---|---|---|
| EIAV | Equine infectious anemia virus | Equine infectious anemia virus |
| OOP | Ovine Progressive Pneumonia | Sheep copper visna virus |
| CAEV | Caprine-ovine arthritis-encephalitis virus | Arthritis-encephalitis virus of goats and sheep |
| BIV | Bovine immunodeficiency virus | bovine immunodeficiency virus |
| FIV | Feline immunodeficiency virus | Feline Immunodeficiency Virus |
| PLV | puma lentivirus | Lentivirus pum |
| SIV | Simian immunedeficiency virus | Simian immunodeficiency virus. Several strains of this virus are known. Each strain is characteristic of one primate species: SIV-agm, SIV-cpz, SIV-mnd, SIV-mne, SIV-mac, SIV-sm, SIV-stm |
| HIV-1 | Human immunodeficiency virus-1 | AIDS virus |
| HIV-2 | Human immunodeficiency virus-2 | Human immunodeficiency virus-2 |
The most well studied is HIV.
Varieties of HIV
The human immunodeficiency virus is characterized by a high frequency of genetic changes that occur in 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 in eukaryotes. The length of the HIV genome is approximately 10 4 nucleotides. 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 HIV research, nevertheless, varieties were found that differed significantly from each other in several ways, in particular, by a different genome structure. Varieties of HIV are indicated by Arabic numerals. To date, HIV-1, HIV-2, HIV-3, HIV-4 are known.
The global HIV epidemic is driven primarily by the spread of HIV-1, with HIV-2 predominating 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 specified, HIV refers to HIV-1.
The structure of the virion
The HIV capsid is surrounded by a matrix coat 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. There are 72 glycoprotein complexes built into the lipid membrane, each of which is formed by three molecules of a transmembrane glycoprotein ( gp41 or TM), serving as the "anchor" of the complex, and three molecules of surface glycoprotein ( gp120 or SU) . Via gp120 the virus attaches to the antigen-CD4 receptor and Co-receptor located on the surface of the cell membrane. gp41 and in particular 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.
HIV genome
HIV genome
The genetic material of HIV is represented by two unconnected strands of positive RNA. The HIV genome contains 9,000 base pairs. The ends of the genome are represented by long terminal repeats (LTRs), which control the production of new viruses and can be activated by both viral proteins and infected cell proteins.
HIV infection
| HIV | |
|---|---|
| ICD-10 | B20. , B21. , B22. , B23. , B24. |
| ICD-9 | - |
The period from infection with the human immunodeficiency virus to the development of AIDS lasts an average of 9-11 years. Statistical data from numerous studies conducted in various countries over a period of more than two decades confirm this conclusion. These figures are valid only for cases where HIV infection is not subjected to any therapy.
High risk groups:
- people who inject drugs using shared utensils for drug preparation (spread of the virus through a syringe needle and shared utensils for drug solutions); as well as their sexual partners.
- men - homosexuals and bisexuals, practicing unprotected anal sex;
- heterosexuals of both sexes who practice unprotected anal sex;
- individuals who received a transfusion of unverified donor blood;
- patients with other venereal diseases;
- persons involved in the sale and purchase of the human body in the field of sexual services (and their clients)
Pathogenesis
PreAIDS- Duration 1-2 years - the beginning of the suppression of cellular immunity. Often recurrent herpes - long-term healing ulceration of the oral mucosa, genital organs. Leukoplakia of the tongue (growth of the papillary layer - "fibrous tongue"). Candidiasis - oral mucosa, genital organs.
Resistance (immunity) to HIV
A few years ago, a human genotype resistant to HIV was described. The penetration of the virus into the immune cell is associated with its interaction with the surface receptor: the CCR5 protein. But the deletion (loss of a gene section) of CCR5-delta32 leads to the immunity of its carrier to HIV. It is assumed that this mutation arose about 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.
Epidemiology
Brief global data on the epidemic of HIV infection and AIDS
According to the December 2006 report of the Joint United Nations Program on HIV/AIDS.
Number of people living with HIV in 2006 Total - 39.5 million (34.1 - 47.1 million) Adults - 37.2 million (32.1 - 44.5 million) Women - 17.7 million ( 15.1 - 20.9 million) Children under 15 - 2.3 million (1.7 - 3.5 million) Number of people infected with HIV in 2006 Total - 4.3 million (3.6 - 6, 6 million) Adults - 3.8 million (3.2 - 5.7 million) Children under 15 - 530,000 (410,000 - 660,000) Number of deaths from AIDS in 2006 Total - 2.9 million (2.5 - 3 .5 million) Adults - 2.6 million (2.2 - 3.0 million) Children under 15 - 380,000 (290,000 - 500,000)
Adult HIV prevalence by country 15–50% 5–15% 1–5% 0.5–1.0% 0.1–0.5%<0.1% нет данных
At the same time, of the total number of infected, two-thirds (63% - 24.7 million) of all adults and children with HIV in the world live in sub-Saharan Africa, mainly in southern Africa. One third (32%) of all people living with HIV in the world live in this subregion, and 34% of all AIDS-related deaths in 2006 occurred here.
Overview of the global epidemiology of HIV/AIDS
In total, about 40 million people in the world are living with HIV infection. Over two-thirds of them inhabit sub-Saharan Africa. The epidemic began here in the late 1970s and early 1980s. The epicenter is considered to be a strip stretching from West Africa to the Indian Ocean. Then HIV spread south. Most of the HIV carriers in South Africa - about 5 million. But on a per capita basis, the figure is higher in Botswana and Swaziland. In Swaziland, one in three adults is infected.
With the exception of countries in Africa, HIV is spreading fastest today in Central Asia and Eastern Europe. Between 2002 and 2002, the number of infected people here almost tripled. These regions contained the epidemic until the late 1990s, and then the number of infected people began to increase sharply - mainly due to drug addicts.
HIV infection in Russia
The first case of HIV infection in the USSR was discovered in 1986. From this moment begins the so-called period of the emergence of the epidemic. The first cases of HIV infection among citizens of the USSR, as a rule, occurred as a result of unprotected sexual contacts with African students in the late 70s of the XX century. Further epidemiological measures to study the prevalence of HIV infection in various groups living on the territory of the USSR showed that the highest percentage of infection at that time was among students from African countries, in particular from Ethiopia. The collapse of the USSR led to the collapse of the unified epidemiological service of the USSR, but not the unified epidemiological space. A short outbreak of HIV infection in the early 90s among men who have sex with men did not spread further, also due to the high level of organization and educational level of this risk group. In general, this period of the epidemic was distinguished by an extremely low level of infection (for the entire USSR less than 1000 detected cases) of the population, short epidemic chains from infecting to infected, sporadic introductions of HIV infection and, as a result, a wide genetic diversity of detected viruses. At that time, in Western countries, the epidemic was already a significant cause of death in the age group from 20 to 40 years.
This prosperous epidemic situation led to complacency in some now independent countries of the former USSR, which was expressed, among other things, in the curtailment of some broad anti-epidemic programs, as inappropriate for the moment and extremely expensive. All this led to the fact that in 1993-95 the epidemiological service of Ukraine was unable to localize two outbreaks of HIV infection in time among injecting drug users (IDUs) in Nikolaev and Odessa. As it turned out later, these outbreaks were independently caused by different viruses belonging to different subtypes of HIV-1. Moreover, the transfer of HIV-positive prisoners from Odessa to Donetsk, where they were released, only contributed to the spread of HIV infection. The marginalization of IDUs and the unwillingness of the authorities to carry out any effective preventive measures among them greatly contributed to the spread of HIV infection. In only two years (1994-95) in Odessa and Nikolaev, several thousand HIV-infected people were identified, in 90% of cases - IDUs. From that moment on the territory of the former USSR, the next stage of the HIV epidemic begins, the so-called concentrated stage, which continues to the present (2007). This stage is characterized by the level of HIV infection of 5 percent or more in a certain risk group (in the case of Ukraine and Russia, this is IDUs). In 1995, there was an outbreak of HIV infection among IDUs in Kaliningrad, then successively in Moscow and St. Petersburg, then outbreaks among IDUs followed one after another throughout Russia in the direction from west to east. The direction of the concentrated epidemic and molecular epidemiological analysis have shown that 95% of all studied cases of HIV infection in Russia have their origin in the initial outbreaks in Nikolaev and Odessa. In general, this stage of HIV infection is characterized by the concentration of HIV infection among IDUs, low genetic diversity of the virus, and the gradual transition of the epidemic from the risk group to other populations.
About 60% of HIV infections among Russians occur in 11 out of 86 Russian regions (Irkutsk, Saratov regions, Kaliningrad, Leningrad, Moscow, Orenburg, Samara, Sverdlovsk and Ulyanovsk regions, St. Petersburg and the Khanty-Mansi Autonomous District).
| Year | Identified cases of infection | The total number of HIV-infected |
| 1995 | 203 | 1 090 |
| 1996 | 1 513 | 2 603 |
| 1997 | 4 315 | 6 918 |
| 1998 | 3 971 | 10 889 |
| 1999 | 19 758 | 30 647 |
| 2000 | 59 261 | 89 908 |
| 2001 | 87 671 | 177 579 |
| 2002 | 49 923 | 227 502 |
| 2003 | 36 396 | 263 898 |
| 2004 | 32 147 | 296 045 |
| 2005 | 35 554 | 331 599 |
| 2006 | 39 589 | 374 411 |
| 2007 | 42 770 | 416 113 |
| 2008 | 33 732 (01.10.2008) | 448 000 (01.11.2008) |
By September 2005, more than 31,000 HIV-infected people were registered in institutions that are part of the Federal Penitentiary Service of the Russian Federation, which is a thousand more than in 2004.
Virus transmission
HIV can be found in almost all body fluids. However, the amount of virus sufficient for infection is present only in blood, semen, vaginal secretions, lymph and breast milk (breast milk is dangerous only for babies - their stomach does not yet produce gastric juice, which kills HIV). Infection can occur when dangerous biological fluids enter directly into the blood or lymph flow of a person, as well as on damaged mucous membranes (which is due to the suction function of the mucous membranes). If the blood of an HIV-infected person comes into contact with an open wound of another person, from which blood flows, infection usually does not occur.
HIV is an unstable virus - it dies outside the body when the blood (sperm, lymph and vaginal secretions) dries out. Domestic infection does not occur. HIV almost instantly dies at temperatures above 56 degrees Celsius.
However, with intravenous injections, the probability of transmitting the virus is very high - up to 95%. Cases of transmission of HIV to medical staff through needle sticks have been reported. To reduce the likelihood of HIV transmission (to fractions of a percent) in such cases, doctors are prescribed a four-week course of highly active antiretroviral therapy. Chemoprophylaxis may also be given to other individuals 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 is highly likely to lead to HIV transmission. To prevent this, special charitable points are being created where drug addicts can receive clean syringes for free in exchange for used ones. In addition, young drug addicts are almost always sexually active and prone to unprotected sex, which creates additional prerequisites for the spread of the virus.
Data on HIV transmission through unprotected sex differ greatly from source to source. The risk of transmission largely depends on the type of contact (vaginal, anal, etc.) and the role of the partner (introducer/receiver).
Protected intercourse, in which the condom broke or its integrity was violated, is considered unprotected. To minimize such cases, it is necessary to follow the rules for the use of condoms, as well as use reliable condoms.
A vertical route of 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%.
The content of the virus in other biological fluids - saliva, tears - is negligible; there is no information on cases of infection through saliva, tears, sweat. Breastfeeding can cause infection because breast milk contains HIV, so HIV-positive mothers are advised not to breastfeed their babies.
Immature and mature forms of HIV (stylized image)
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.
Anti-HIV creams and gels
The Times, referring to the findings of scientists from the University of Minnesota, reports that "glycerol monolaurate" or "lauric ester" used as a food additive, which is part of cosmetics, probably interferes with the signaling processes in the immune system of monkeys, blocking the virus at a key stage of potential Infection". When the virus enters the body, it captures T-cells and spreads through the blood vessels, and lauric ester acts so that the inflammatory reaction does not develop.
People living with HIV
The term People Living with HIV (PLHIV) is recommended for a person or group of people who are HIV positive, as it reflects the fact that people can live with HIV for many years, leading an active and productive life. 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 from PLHIV is “himself to blame” for their HIV status or "deserved" it). The expression “AIDS patient” is only acceptable in a medical context, because most of the life of PLHIV is not spent in a hospital bed.
Legal Consequences of Infecting Another Person with HIV
Infecting another person with HIV infection or putting him or her at risk of contracting HIV infection is criminalized in a significant number of states. In Russia, the corresponding penalties are provided for in article 122 of the Criminal Code of the Russian Federation.
Sources of information
- Palella F. J. et al. Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. HIV Outpatient Study Investigators. The New England journal of medicine, 1998, v. 338, p. 853-860.
- UNAIDS/WHO AIDS Epidemic Update: December 2006 . PDF file, 2.7 MB
- Greener, R. "AIDS and macroeconomic impact", in S, Forsyth (ed.): State of The Art: AIDS and Economics, IAEN, - 2002, p. 49-55.
- Wolfgang Hübner (2009). "Quantitative 3D Video Microscopy of HIV Transfer Across T Cell Virological Synapses". Science 323: 1743-1747. DOI:10.1126/science.1167525 http://www.sciencemag.org/cgi/content/full/323/5922/1743
- Wolfgang Hübner (2009). "Quantitative 3D Video Microscopy of HIV Transfer Across T Cell Virological Synapses". Science 323: 1743-1747. DOI:10.1126/science.1167525 (Photo) http://www.sciencemag.org/content/vol323/issue5922/images/small/323_1743_F1.gif
- Wolfgang Hübner (2009). "Quantitative 3D Video Microscopy of HIV Transfer Across T Cell Virological Synapses". Science 323: 1743-1747. DOI:10.1126/science.1167525 (Video) http://www.youtube.com/watch?v=1wTCYnWYsCQ
- Kaposi's sarcoma and Pneumocystis pneumonia among homosexual men--New York City and California. Morbidity and Mortality Weekly Report, 1981, v. 30, p. 305.(English)
- Centers for Disease Control. Pneumocystis Pneumonia--Los Angeles. Morbidity and Mortality Weekly Report, 1981, v. 30, p. 250.(English)
- The history of AIDS 1981-1986
- Centers for Disease Control. Current trends update on acquired immune deficiency syndrome (AIDS) --United States. Morbidity and Mortality Weekly Report, 1982, v. 31, p. 507.(English)
- Gottlieb et al. Pneumocystis carinii pneumonia and mucosal candidiasis in previously healthy homosexual men: evidence of a new acquired cellular immunodeficiency; N. Engl. J. Med. 1981, 305 1425-1431
- Durack D. T. Opportunistic infections and Kaposi's sarcoma in homosexual men; N. Engl. J. Med. 1981, 305 1465-1467
- Goedert et al. Amyl nitrite may alter T lymphocytes in homosexual men; Lancet 1982, 1 412-416
- Jaffe et al. National case-control study of Kaposi's sarcoma and Pneumocystis carinii pneumonia in homosexual men: Part 1, Epidemiologic results; Ann. Int. Med. 1983, 99 145-151
- Mathur Wagh et al. Longitudinal study of persistent generalized lymphadenopathy in homosexual men: Relation to acquired immunodeficiency syndrome; Lancet 1984, 1, 1033-1038
Many people ask the question: What is AIDS? This is the final stage of the disease caused by the human immunodeficiency virus - HIV (see photo below). Thus, from what has been said, we can conclude the difference between these two concepts.
HIV and AIDS: what's the difference
So how is HIV different from AIDS? The difference is that the first abbreviation denotes the name of the virus - the cause of the disease, and the second - the disease itself, manifested in the form of acquired immunodeficiency syndrome. Do not confuse these two concepts, as they are not identical!
What is HIV infection
HIV infection is a disease caused by. This virus contains two identical RNA molecules, each containing complete genetic information. An important feature of the causative agent of AIDS is pronounced lymphotropism, especially to T-lymphocytes "helpers". A certain relationship between the virus and the histocompatibility antigens of the HLA system was revealed.
The stages of the HIV replication cycle are shown in the figure below.
Specific interaction of the virus on the surface of the cell membrane (1) with subsequent penetration into the cell (2); synthesis of a DNA copy of the RNA genome of the virus using reverse transcriptase (3); the transition of virus-specific DNA from the cytoplasm of an infected cell to its nucleus (4) and the incorporation of virus-specific DNA into the genome of the host cell (5); assembly and budding of newly formed particles (6). Under the influence of viral gene expression products, the host cell undergoes degeneration or neoplastic transformation. These cytopathic effects are an important feature of HIV infection and are uncharacteristic of most retroviruses. The cytopathic effect of the infectious agent is associated with the presence of a virus-specific transactivating factor.
How HIV is transmitted from person to person
The human immunodeficiency virus is isolated in almost all body fluids: from saliva to cerebrospinal fluid. It is found directly in brain tissue, lymph nodes, bone marrow cells and skin. But, despite the vastness of localizations, only through blood and semen can HIV be transmitted from person to person. Therefore, the common question among the population “is HIV transmitted through saliva” can only be answered in the negative.
Infection in the vast majority of cases occurs sexually with homo- and heterosexual contacts. The virus can be transmitted by transfusion of whole blood, red blood cells and plasma. Most cases of AIDS in children are associated with congenital from a sick mother to a child, as well as with transplacental infection. A number of cases of the disease are due to the transmission of the human immunodeficiency virus by intramuscular, intravenous and subcutaneous injections, medical scarifications or tattoos.
Groups at risk of HIV infection
- Homosexuals
- Bisexuals
- People who use drugs
- Patients with hemophilia
- Prostitutes
- Children of mothers with AIDS
- Patients with venereal diseases
The key mechanism for the diverse disorders of the cellular and humoral immune status in HIV is that the AIDS virus primarily affects T-helpers as a result of its cytopathic effect of the etiological factor.
The main manifestations of impaired functioning of the immune system in AIDS are presented below.
Immune system disorders in human immunodeficiency virus
- Decrease in the total number of circulating lymphocytes
- Decrease in the number of T-helpers and changes in the content of T-suppressors, leading to a decrease in the ratio of T-helpers / T-suppressors in AIDS - less than 1; normal - about 2
- Decreased delayed-type hypersensitivity reaction Decreased production of lymphokines
- Increased levels of serum immunoglobulins and circulating immune complexes
- Functional disorders of monocytes / macrophages: reduced chemotaxis, spontaneous increase in the production of such as interleukin-1 and prostaglandin E 2
- High serum titer of altered acid-labile interferon alpha
The incubation period of HIV before the onset of the first symptoms and the development of manifest forms of AIDS can be quite long and depends on the ways and nature of infection, the size of the infectious dose of the pathogen, as well as other factors that contribute to the reproduction of the virus in the body.
The average incubation period is 12-15 months, with fluctuations from 2 weeks to 2-4 years or more.
A shorter incubation period is observed with homosexual and parenteral routes of infection and in children born from sick parents.
Antibodies to HIV can be determined as early as 2-8 weeks after infection, but the seronegative period is sometimes delayed up to 6 or more weeks.
Depending on the characteristics of the symptoms, the course of the infectious process in AIDS can be:
- asymptomatic
- clinically pronounced
- rapidly progressing.
The first symptoms of HIV
The first symptoms of AIDS are as follows:
- Fever up to 1 month or more
- Generalized lymphadenopathy
- Weight loss (10% or more)
- Long term (at least 2 months)
- Anemia
- Opportunistic infections:
- :
- generalized candidiasis,
- herpes infection,
- kaposi's sarcoma,
- cytomegalovirus and bacterial infections,
- tuberculosis
- :
- HIV-associated CNS lesions:
- dementia,
- myelopathy,
- peripheral neuropathy,
- aseptic meningitis
- Pneumocystis pneumonia
- Laboratory indicators:
- lymph and leukopenia,
- thrombocytopenia,
- erythropenia,
- signs of deficiency of humoral and cellular immunity
Diagnosis of HIV infection
For the serological diagnosis of HIV infection, methods of enzyme immunoassay have found application primarily. Two modifications of this method have been developed in Russia. A common disadvantage of enzyme immunoassay methods for studying AIDS is the rather high frequency of false positive reactions. They are due to the very nature of this particular disease, in which the decay of virus-affected cells is accompanied by the release of various cellular antigens into the blood, to which antibodies are produced. A positive AIDS enzyme immunoassay is a primary screening method and must be confirmed by immunoblotting.
Immunoblot for HIV
The meaning of the immunoblot is as follows:
The purified virus is destroyed with a detergent, its proteins are separated by gel electrophoresis, and then they are transferred to nitrocellulose strips. The reaction is set by immersing the strip with the virus protein in the test serum, diluted in a buffer solution, adding a conjugate of antibodies to human immunoglobulins, washing, staging and recording the enzymatic reaction.
The immunoblot reaction in AIDS is quite specific, since after the separation of proteins by electrophoresis, each of them occupies a strictly defined place depending on its molecular weight.
The Institute of Immunology of the Russian Academy of Medical Sciences has developed a highly sensitive and safe test system "Peptoscreen", based on the use of synthetic antigens for antibodies against the virus.
When using any diagnostic AIDS tests, in order to increase the reliability of positive test results for the presence of antibodies to HIV, it is advisable to repeat the reactions with the same reagents or additionally carry out a parallel reaction under identical conditions.
During the initial examination of risk groups, as well as in the absence of data in dynamics, the test results obtained cannot yet reliably indicate the absence or presence of AIDS. Primary positive results require increased attention when conducting a repeated in-depth study of a sick or suspected donor, including epidemiological, immunological and clinical methods.
The survey of the population and donors for the diagnosis of HIV infection is the most important, but not the only, but rather the first link in the overall system for tracking the spread of the disease and identifying individuals - sources of infection.
HIV treatment
Groups of drugs for antiretroviral therapy of AIDS (photo clickable) Treatment of HIV patients should be carried out in a hospital with subsequent dispensary observation and periodic hospitalization. An AIDS patient should be informed about the diagnosis and warned about the criminal liability for infecting others.
Infected, but not sick, are subject to periodic (at least 1 time per quarter) re-examination to identify the dynamics of the infectious process and the possible detection of symptoms of AIDS in an active form or, conversely, recovery.
Persons with antibodies to the human immunodeficiency virus who do not have the expression of the virus should be re-examined at least once every 6-10 months. They must be warned that they cannot donate blood.
The list of drugs for antiretroviral therapy for human immunodeficiency virus is presented in the photo above.
The combination of medicines and the frequency, as well as the duration of their intake, should be determined exclusively by the doctor!
HIV is curable or not?
This question worries many, especially those infected with AIDS. Unfortunately, despite the achievements of scientists in the development of drugs for antiretroviral therapy of the human immunodeficiency virus, there is still no drug that can cure HIV. AIDS can only be put into remission, but the body cannot be rid of it.
Today it is one of the most dangerous diseases, and it is still impossible to cure it. To understand why this happens, you need to find out which cells the AIDS virus infects. First of all, the main blow is taken by the human immune system, as a result of which the pathologies of various internal organs begin to constantly develop.
As soon as vital structures are affected, the patient's condition begins to deteriorate rapidly, bringing death closer. To avoid such a manifestation, or at least to postpone it as much as possible, it is necessary to carry out diagnostics in a timely manner and adhere to retroviral therapy.
What cells does HIV infect?
It is worth remembering that T-lymphocytes are primarily affected in HIV infection. Which cells the virus that causes AIDS infects depends on their structure. The main targets are structures that contain CD4 receptors. They contribute to the attachment of the pathogen.
As a rule, the AIDS virus infects helper cells, less often monocytes and macrophages suffer. This is explained by the fact that only these structures have CD4 receptors. Through them, the pathogen enters the nucleus and is introduced into the DNA. From that moment on, a person is infected, the disease begins to develop.
After the introduction of the disease actively develops, the virus gradually spreads throughout the body and can damage the heart, liver, kidneys and other vital organs. Over time, AIDS affects target cells and leads to their death, as a result, immunity gradually decreases, which provokes the development of secondary pathologies.
Not every person knows which cells are affected by AIDS. This question is actually not so important, while the signs of the disease must always be remembered. This will allow you to suspect infection in a timely manner and proceed with therapeutic measures.
The AIDS virus infects white cells in human blood, this is what people call lymphocytes, which are protective. Their main function is the fight against infectious processes of any etiology. If pathology starts in the body, the number of lymphocytes increases dramatically, and they are sent directly to the problem area. When the HIV virus infects lymphocyte cells, this process cannot take place in a full-fledged way. This is the reason for the often recurring diseases in AIDS.
HIV lesions from the nervous system
In about 90% of all cases, the nervous system suffers in an immunodeficient state. Manifestations can occur both at the beginning and during the transition of the disease to the stage of secondary manifestations. In some cases, neurological symptoms are the only sign of AIDS.
If HIV infection is present, damage may occur at an early stage. Then the following pathological conditions can be observed in the body:
- Meningoencephalitis.
- Dementia.
- Polyneuropathy.
- Neuropathy of the facial nerve.
- Myelopathy.
- Disorder of the peripheral nervous system.
- Guillain-Barré syndrome.
During the period of secondary signs, the AIDS virus also affects the nervous system. In this case, the following problems are observed:
- Meningomyelitis.
- Meningitis.
- brain abscess.
- Various innovations.
- Infarction of individual parts of the brain.
The lesions of HIV infection listed above should not be ignored. Each of them requires indispensable treatment, otherwise the lethal outcome becomes much closer.
Are the lungs affected?
Analyzing how the respiratory organs react to the pathogen, it is worth noting that, first of all, the immunodeficiency virus (HIV) affects the lungs. Almost every patient has pneumocystis pneumonia. It is accompanied by an unproductive cough, fever, shortness of breath, chest pain. On the radiograph, it is possible to detect areas of infiltration.
When the immunodeficiency virus infects the lungs, bronchitis often develops. Cough is accompanied by sputum production. It is not difficult to cure the pathology, but it is prone to constant relapses.
Various fungi, cytomegalovirus, bacteria can also provoke lung pathologies. As a result, patients often suffer coccidioidomycosis, histoplasmosis. At later stages, tumors develop, among them Kaposi's sarcoma and non-Hodgkin's lymphoma are most often diagnosed.
Although HIV predominantly affects protective cells in the human body, such a terrible disease as tuberculosis is often observed from the respiratory organs. It can occur at any stage of AIDS. It manifests itself with classic symptoms and requires mandatory treatment.
How does HIV affect the heart and blood vessels?
After entering the body, HIV infects T-lymphocyte cells that are in the blood, but a small number of them are also located in the myocardium. Therefore, the heart also suffers when entering this infection.
Unfortunately, it is not yet possible to prevent the development of pathologies of the cardiovascular system, since retroviral therapy helps to reduce the risk of secondary lesions, but at the same time it itself has a detrimental effect on the state of the heart muscle.
If the virus that causes AIDS infects the heart, patients experience myocarditis, cardiopathy. Also, often as a result of a bacterial or viral infection, secondary pathologies, it is possible to detect an effusion in the pericardial sac. Sometimes it goes away on its own without treatment.
In some cases, when the human body is affected by the immunodeficiency virus, rapidly developing cardiac tamponade is observed. The appearance of such a problem is the reason for the appointment of an HIV test. In the last stages of AIDS, thrombotic processes and thromboembolic complications often develop.
Does the human immunodeficiency virus infect the kidneys?
Answering the question: which organs are affected by HIV, one cannot but note the effect on the kidneys. Very often, patients suffer from kidney failure. Various kinds of nephropathy are accompanied by significant proteinuria. A distinctive feature of such pathologies is that they progress in a fairly short time due to the detrimental effect of the virus on the interstitial tissue of the organ.
Not uncommon are glomerulonephritis, which occurs in association with hepatitis B or C. The body of an infected person becomes quite susceptible to various bacteria, viruses, fungi, it is this microflora that often causes kidney damage, which results in inflammatory processes.
It is also worth knowing that HIV in the body affects the kidneys not only by infectious processes. Against its background, malignant neoplasms can develop, sometimes the organ suffers from metastases of tumors that spread from other structures.
To eliminate the pathological process, complex treatment is used, it must necessarily contain powerful antiviral drugs.
Does the alimentary canal suffer?
The digestive organs suffer from AIDS in almost every patient, and the virus is able to infect the canal along its entire length. First of all, there are changes in the oral cavity. Stomatitis is predominantly of fungal origin. Herpes, hairy leukoplakia of the oral cavity is also noted, in most cases it is asymptomatic, sometimes it can be accompanied by pain.
In advanced stages in the palate, changes characteristic of Kaposi's sarcoma can be detected - red or brown foci, painful, may be flat or protrude slightly above healthy surfaces.
However, the most common manifestation of damage to the digestive system is diarrhea. In most cases, it develops as a result of the addition of intestinal infections (salmonellosis, dysentery, and others).
Hepatitis C and B are often diagnosed in patients who use drugs. Also, these diseases can be triggered by cytomegalovirus, Epstein-Barr virus, the use of medications during retroviral therapy.
Thus, it can be argued that the human immunodeficiency virus affects not only individual cells that protect the body from infections, but also almost every organ. Therefore, therapeutic measures should begin immediately after the diagnosis of a serious illness. This will help reduce the rate of progression of AIDS and reduce the likelihood of developing secondary pathologies.
In 1983, a group of scientists from the University of Paris, and then their American colleagues, isolated the human immunodeficiency virus (HIV) from the blood of AIDS patients. It attacks the human immune system, rendering it unable to protect the body from disease. For the third decade there has been a fight against dangerous pathogenic protozoa, but we have not yet fully figured out HIV. It still remains a mystery how the AIDS virus infects the defense system and why some patients infected with this infection remain completely healthy people for a long time.
Features of cell infection
Only HIV can infect and then kill the cellular tissue of the human immune system. When the virus first enters the blood or mucous membranes, immune cells begin to fight it, but they always lose. HIV can only infect macromeres (cells) that contain special proteins (CD4 receptors) on their surface. A number of human cell tissues contain everything necessary for the virus to be able to penetrate them.
What cells are affected by the AIDS virus? The main target for HIV are T-helpers. But CD4 receptors are also found on the outer surface of other cells (eg, thymocytes, macrophages, intestinal epithelium, cervix).
All of them also serve as target cells for HIV. The impact of the immunodeficiency virus on macromeres depends on their type. So, penetrating into a nerve cell, it almost does not damage its sheath. Therefore, having become infected, it continues to work for a considerable time and serve as a refuge for the virus. Cells that live for a long time can contain many pathogenic organisms and be their repository. In them, HIV is not vulnerable to the action of drugs and the immune system. And for storage cells, this does not pass without a trace, their structure is greatly modified.
The difference between HIV infection and AIDS
Some believe that HIV and AIDS are one and the same. Is it so? HIV (human immunodeficiency virus) damages the immune system, and it ceases to protect the body from infections.
A few years after contracting HIV, a weakened patient develops serious illnesses, then he is diagnosed with AIDS (acquired immunodeficiency syndrome). This means that HIV is a virus that depresses the immune system, and AIDS is a whole bunch of diseases caused by the causative agent of the AIDS virus.
Risk factors
Immunodeficiency is a dangerous and incurable disease. Infection with HIV in most cases occurs due to the wrong behavior of people, and not because they belong to a certain group that has an increased risk of developing the disease.
There are several risk factors that contribute to contracting AIDS.
Main:
- use of one syringe by different persons;
- promiscuous sex;
- unverified donor material;
- contact of medical staff with an infected patient;
- prostitution.
Biological:
- the presence of sexually transmitted diseases (gonorrhea, syphilis, chlamydia, trichomoniasis);
- defects in the structure of the genital organs (injured, narrow, with neoplasms);
- high viral loads (the more virus in the blood, the greater the possibility of infection);
- weak immune system;
- violations of the skin and mucous membranes;
- genetic characteristics of the virus (different strains have different speed of movement, aggressiveness, the ability to defeat cellular material).
Psychological:
- personal qualities of character (pedantry, impulsiveness, risk-taking, ardor, inability to control oneself);
- attitudes towards HIV and AIDS;
- communication style;
- mental disorders;
- depressive state.
How the AIDS virus spreads
Only when a person comes into contact with biological fluids (blood, semen, vaginal secretions) and tissues or organs that contain the virus can AIDS spread.
- The most dangerous is contact with blood. After a single transfusion of infected blood, human infection occurs in almost 100% of cases.
- Vertical transmission of the virus (from mother to fetus) ranks second (about 30%).
- With a single use of medical instruments (needles, syringes) containing HIV-infected blood, the probability of being infected with the AIDS virus is about 1%.
- HIV infection is much less common through sexual contact. Moreover, it was found that infection of a woman from a man happens twice as often as infection of the stronger sex from the weak. It is noticed that the use of condoms significantly reduces the likelihood of infection during sexual contact.
- The very low possibility of contracting an infection from an accidental needle stick, it is only 0.3%.
HIV incubation period
In the first stage, AIDS patients do not show any signs of the disease. The virus has just entered the body and did not have time to gain a foothold. It can only be detected by a blood test. The latent period of the disease lasts approximately three months. It depends on the immune system of the patient.
Symptoms
In AIDS patients, the onset of the disease is very difficult to detect. Its earliest symptoms are:
- swollen lymph nodes;
- pathological conditions similar to influenza (cough, fever, appetite disappears, body aches, fatigue, general weakness).
These symptoms may also be present in other diseases. But if a person had sexual intercourse or there was some kind of medical intervention, then a blood test for HIV infection should be taken. An infected patient may not have symptoms, but despite this, he can already infect another person. Sometimes only a few years after infection, when the AIDS virus attacks immune cells, late signs of the disease appear:
- constant night sweats and fever;
- constant fatigue;
- loss of weight and appetite for no reason;
- enlarged and painful lymph nodes;
- tumor formations on the skin, in the mouth and nose of a dark red color;
- frequent acute respiratory infections;
- dry cough, shallow breathing.
Fighting AIDS in men and women
The male sex is much less concerned about their health than the female. Symptoms of HIV infection in them appear earlier, but are blurred and are often perceived as signs of colds. Not taking the problem seriously, men do not go to the doctor in time, and the diagnosis is made when the AIDS virus already infects the cells of the immune system.
Women are much more attentive to their health, and the disease process in them is much slower than in men. Along with the general symptoms of the disease, female representatives may experience vaginal discharge with a mucous structure, pain during menstruation, and breast enlargement. Unlike men, they often have an increase in lymph nodes in the genital area. All this causes a feeling of discomfort, anxiety, insomnia, depression. A woman is forced to see a doctor with existing symptoms that may indicate the presence of the immunodeficiency virus.
Is it true that the AIDS virus dies quickly?
About the "survivability" of HIV, the existing data are often contradictory. It is known that in the open air after a few minutes the virus ceases to exist. But in the inner part of the syringe, its vital activity continues much longer. How long does the AIDS virus live outside the human body? Answering this question, it should be noted that there are many misconceptions and misinterpretations of scientific research.
Under laboratory conditions, when the concentration of the virus exceeds the real value by 100,000 times, the survivability of HIV is from one to three days from the moment the liquid dries. According to these data, the virus outside the body can live only a few minutes. For this reason, infection by domestic means does not occur. But the survivability of pathogenic organisms in a hollow needle and inside a syringe depends on:
- volume of blood in the needle;
- the amount of virus in the blood;
- temperature.
According to the results of the research, it was found that with a high concentration of viral particles in the blood, it can exist for up to 48 days, gradually reducing its vital activity. With low blood volumes, small amounts of virus, and high temperatures, the lifespan of HIV is greatly reduced.
Temperature and HIV
The belief that a virus outside the human body is instantly destroyed at room temperature is erroneous. Of course, HIV is not a bacterium, does not contain spores, and therefore does not live in soil and water for months. Nevertheless, it is covered with a protein shell and in a dry drop of mucus or blood can live for several days, and under suitable conditions for several weeks. Over time, the number of pathogenic organisms decreases significantly, so a small number of them are not able to infect a person. Yes, and the virus from the external environment enters the skin, lungs or digestive tract, and not into the blood.
At what temperature does the AIDS virus die? The immunodeficiency virus is really unstable to elevated temperature. When the infected material is heated to 56 degrees for 30 minutes, almost all pathogenic organisms are killed, and when boiled, their death occurs almost instantly. In the presence of a high content of viral particles (blood clots), boiling should be carried out a little longer to neutralize.
Is there a cure for AIDS?
A patient with an immunodeficiency virus, without resorting to treatment, can live from 5 to 10 years. A magic vaccine for AIDS patients has not yet been found, but scientists are successfully working on its invention. There are already medicines that do not allow the virus to multiply, stop the disease, preventing the transition of HIV into AIDS. Patients using medications are in a satisfactory condition and can work. Doctors believe that their life expectancy will increase significantly.
Prevention
While the search for an effective vaccine against the immunodeficiency virus is underway, the only effective means of combating infection is educational activities among the population. The most effective and effortless method of AIDS prevention is cleanliness in personal relationships. For this you should:
- use only your own personal hygiene products;
- have one partner;
- use condoms;
- avoid sexual intercourse with strangers;
- avoid group contact.
The second direction of prevention is activities in medical institutions:
- examination and control over donors, patients at risk, pregnant women;
- monitoring childbearing of infected women;
- use only sterile medical instruments, disposable syringes and blood transfusion systems.
A healthy lifestyle based on physical activity, reasonable nutrition, real rest, rejection of bad habits and stress is the best prevention of AIDS.
