- What is HIV infection
- What triggers / Causes of HIV infection
- Pathogenesis (what is happening) during HIV infection
- The symptoms of HIV infection
- Diagnosis of HIV infection
- Treatment of HIV infection
- Prevention of HIV infection
- Which doctors should be consulted if You have HIV infection
What is HIV
HIV - antropos viral disease, the pathogenesis of which is a progressive immunodeficiency and development as a consequence of secondary opportunistic infections and neoplastic processes.
The history of the discovery of HIV,
The human immunodeficiency virus was discovered in 1983, the study of the etiology of AIDS. The first official scientific reports of AIDS were two articles about unusual cases of Pneumocystis pneumonia and Kaposi's sarcoma in male homosexuals, published in 1981. In July 1982 for the first time to designate a new disease has been proposed, the term AIDS (AIDS). In September of the same year based on the number of opportunistic infections were diagnosed in (1) male homosexual activities, (2) addicts, (3) patients with hemophilia A and (4) Haitians, AIDS was first given a full definition of how the disease. In the period from 1981 to 1984 he published several papers linking the risk of AIDS from anal sex or the influence of drugs. In parallel, work was carried out on the hypothesis of the possible infectious nature of AIDS. The human immunodeficiency virus independently opened in 1983 in two laboratories:
. at the Pasteur Institute in France under the leadership of Luc Montagnier (FR. Luc Montagnier).
. the National cancer Institute in the USA under the leadership of Robert Gallo (eng. Robert C. Gallo).
The results of studies in which tissues from patients for the first time managed to allocate a new retrovirus, were published on 20 may 1983 in the journal Science. In these articles reported the discovery of a new virus belonging to the group of HTLV viruses. Researchers have suggested that isolated them viruses can cause AIDS.
May 4, 1984, the researchers reported the isolation of the virus, which bore at that time the name HTLV-III, lymphocytes from 26 of 72 AIDS patients and 18 out of 21 patients with pre-AIDS condition. None of 115 healthy heterosexual individuals of the control group, the virus could not be found. The researchers noted that a small percentage of virus isolation from the blood of AIDS patients caused by the low number of T4 lymphocytes, cells in which, presumably, HIV multiplies.
In addition, scientists reported the detection of antibodies to the virus, identification previously described in other previously unknown viruses and antigens of HTLV-III and on the observation of virus reproduction in a population of lymphocytes.
In 1986 it was discovered that the virus, discovered in 1983 by French and American researchers genetically identical. The original title of viruses have been eliminated, and the proposed one name - HIV.
In 2008, Luc Montagnier and Francoise Barre-Sinoussi were awarded the Nobel premiei in physiology and medicine "for his discovery of human immunodeficiency virus".
Reservoir and source of infection - HIV infected people, in all stages of the infection for life. The natural reservoir of HIV-2 African monkeys. The natural reservoir of HIV-1 not detected, it is possible that it can be wild chimpanzees. In laboratory conditions, HIV-1 causes chimpanzees and some other species of monkeys are not clinically defined infection, ending with a quick recovery. Other animals are not susceptible to HIV.
In a large number of virus found in blood, semen, menstrual secretions, and vaginal secretions. In addition, virus found in women's breast milk, saliva, tear and cerebrospinal fluids. Greatest epidemiological risk are blood, semen and vaginal secretions.
The presence of foci of inflammation or violation of the integrity of the mucous membranes of the genital organs (such as cervical erosion) increase the likelihood of HIV transmission in both directions, becoming a weekend or a gateway for HIV. The probability of infection during a single sexual encounter is low, however, frequent sexual intercourse makes this the most active way. Household transmission of the virus is not installed. Transmission of HIV from mother to fetus is possible with the defects of the placenta, leading to the penetration of HIV into the bloodstream of the fetus, and also with the trauma of the birth canal and the baby during childbirth.
Parenteral route is also implemented through blood transfusion, Packed red cells, platelets, fresh frozen plasma and. Intramuscular, subcutaneous injection and random injections of infected needle average of 0.3 cases (1 case of 300 injections). Among children born from infected mothers or vskarmlivanija they are infected with 25-35. Infection of the child during birth and through breast milk.
The natural susceptibility of people is high. In recent times considering the insignificant existence of genetically different populations, occurring particularly often among the Nordic peoples, rarely becoming infected through sexual contact. The existence of this variation in susceptibility is associated with the gene CCR5 - people with the homozygous form of the gene are resistant to HIV. The latest data show that the cause of immunity to HIV infection can be specific IgA detected in the mucous membranes of the genitals. People infected over the age of 35 years, AIDS is two times faster than those infected at a younger age.
Life expectancy with HIV is 11-12 years. However, the advent of effective chemotherapy drugs significantly prolong the life of HIV-infected persons. Among those dominated by people of sexually active age, mainly men, but an annual increase in the percentage of women and children. In recent years, Ukraine was dominated by the parenteral route of infection (if you use one syringe several persons), mainly among drug users. At the same time noted an increase in the absolute number of transmission through heterosexual transmission, which is quite understandable, as addicts become a source of infection for their sexual partners. The rate of occurrence of HIV infection among donors has increased dramatically (more than 150 times compared to the beginning of the epidemic period), it is also very dangerous donors in the period of "seronegative" window. Detection of HIV among pregnant women in recent years has increased dramatically.
Basic epidemiological characteristics. Currently the world is experiencing a pandemic of HIV infection. If in the first years of the appearance of the disease the highest number of cases was registered in the United States, now the infection is more prevalent among the population of countries in Africa, Latin America, South-East Asia. In several countries in Central and South Africa by up to 15-20% of the adult population infected with HIV. In Eastern Europe, including in Ukraine in recent years have noted the intensive growth of infection of the population. The distribution of morbidity across the country is uneven. The most affected cities.
The spread of HIV infection is associated mainly with unprotected sex, use of infected syringes, needles and other medical and paramedical instruments, virus transmission from an infected mother to child during childbirth or breastfeeding. In developed countries, mandatory testing of donated blood significantly reduced possibility of transmission when using it.
Timely 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 because of their high cost.
The evaluation of the joint UN programme on HIV/AIDS (UNAIDS) and world health organization (who), from 1981 to 2006 from diseases associated with HIV infection and AIDS has killed 25 million people. Thus, the HIV infection is one of the most devastating epidemics in human history. Only in 2006, HIV was the cause of death of about 2.9 million people. By the beginning of 2007 worldwide, around 40 million people (0,66 population) were carriers of HIV. Two-thirds of the total number of HIV-infected people live in Africa South of the Sahara desert. In the most affected by the pandemic of HIV and AIDS countries, the epidemic impedes economic growth and increases poverty.
What triggers / Causes of HIV infection:
HIV - the human immunodeficiency virus that causes the disease - HIV infection, the last stage which is known as acquired immunodeficiency syndrome (AIDS) - unlike congenital immunodeficiency.
The human immunodeficiency virus belongs to the family of retroviruses (retroviridae are), the genus of lentivirus (Lentivirus). The name Lentivirus is derived from the Latin word lente - slow. This name reflects one of the characteristics of viruses of this group, namely the slow and uneven rate of development of infectious process in the host. For lentiviruses also characterized by a long incubation period.
For human immunodeficiency virus characterized by high frequency of genetic changes that occur in the process of self-reproduction. The error rate in HIV is 10minus-3 - 10minus-4 errors / (genome * the replication cycle) that is several orders of magnitude more than the same size in eukaryotes. The length of the HIV genome is about 104 nucleotides. This implies that almost every virus of the at least one nucleotide different from its predecessor. In the nature of HIV exists in the form of multiple quasi-species, being one taxonomic unit. During the study, HIV still varieties were found, which differed significantly from each other on several grounds, in particular different structure of the genome. Types of HIV are identified with Arabic numerals. Today known HIV-1, HIV-2, HIV-3, HIV-4.
. HIV-1 is the first representative of the group, opened in 1983. Is the most common form.
. HIV-2 - type of the human immunodeficiency virus identified in 1986. Compared with HIV-1, HIV-2 is studied to a much lesser extent. HIV-2 differs from HIV-1 in the genome structure. It is known that HIV-2 is less pathogenic and is transmitted less likely than HIV-1. Noted that people infected with HIV-2, have weak immunity to HIV-1.
. HIV-3 is a rare variety, the opening of which was reported in 1988. Found virus did not react with antibodies to other known groups, and also possessed considerable differences in the genome structure. More common name for this species is HIV-1 subtype O.
. HIV-4 - a rare virus discovered in 1986.
The global epidemic of HIV infection is mainly due to the spread of HIV-1. HIV-2 is mostly spread in West Africa. HIV-3 and HIV-4 does not play a significant role in the spread of the epidemic.
In most cases, unless agreed otherwise, under HIV refers to HIV-1.
The structure of HIV virion
The HIV virions are spherical particles, the diameter of which is about 100-120 nm. This is approximately 60 times smaller than the diameter of the erythrocyte.
The Mature capsid of the virion has the shape of a truncated cone. Sometimes there are "multi-core" virions containing 2 or more nucleoids.
The composition of the Mature virion consists of several thousand protein molecules of various types.
Names and functions of main structural proteins of HIV-1.
Inside the capsid of HIV is balkanology complex: two strands of viral RNA, viral enzymes (reverse transcriptase, protease, integrase) and p7 protein. The capsid proteins are also associated Nef and Vif (7-20 Vif molecules per virion). Inside the virion (and, most likely, outside of the capsid) protein found Vpr. The capsid is formed by ~2,000 copies of the viral protein p24. The stoichiometric ratio of p24:gp120 in the virion is 60-100:1, and p24:Pol about 10-20:1. In addition, the capsid of HIV-1 (but not HIV-2) contact ~200 copies of the cell cyclophilin And that the virus borrows from the infected cells.
The HIV capsid is surrounded by a matrix sheath formed by ~2,000 copies of matrix protein p17. Matrix shell is in turn surrounded by a lipid bilayer membrane, which is the outer shell of the virus. It is formed by molecules, captured by the virus during its otokoyaku from the cage in which it was formed. In a lipid membrane built-72 glycoprotein complex, each of which is formed by three molecules of the transmembrane glycoprotein (gp41 or TM) that serve as "anchor" of the complex, and three molecules of the surface glycoprotein (gp120 or SU). Using virus gp120 attaches to CD4 receptor and co-receptor on the surface membrane of cells. gp41 and especially gp120 intensively studied as targets for drugs and vaccines against HIV. In the lipid membrane of the virus are also membrane proteins of cells, including human leukocyte antigens (HLA) classes I, II and adhesion molecules.
Pathogenesis (what is happening) during HIV infection:
The risk of Contracting HIV
High risk groups:
. persons who inject drugs using shared utensils for preparing drugs (the spread of the virus through a needle of the syringe and the same dishes for solutions of drugs)- as well as their sexual partners.
. person (regardless of sexual orientation), practicing unprotected anal sex (in particular, approximately 25 cases of unprotected anal sex among HIV-positive gay men are so-called "barebackers" [comprising about 14 of all the gays in the surveyed sample] - the face, deliberately avoiding the use of condoms, despite their awareness about the possibility of Contracting HIV- a small proportion among barebackers are "bug chasers" - the person, purposefully seeking to contract HIV and selects as partners for sex HIV positive or potentially positive individuals called "gift-givers")
. persons who have had a transfusion of unscreened donor blood-
. those suffering from other sexually transmitted diseases-
. individuals associated with the sale and purchase of human body in the sex industry (prostitutes and their clients)
HIV can be contained in almost all biological fluids. However, sufficient for infection the amount of virus is present only in blood, semen, vaginal secretions, lymph and breast milk (breast milk only dangerous for babies in their stomach still produces gastric juice, which kills HIV). Infection can occur by ingestion of dangerous biological liquids directly into the blood or lymph of a person, as well as the damaged mucous membranes (due to the suction function of the mucous). If the blood is infected with HIV gets into an open wound of another person, from which the blood flows, the infection usually does not occur.
HIV is unstable outside the body in dried blood (semen, lymph, vaginal secretions) he dies. Household by infecting occurs. HIV dies almost instantly at temperatures above 56 degrees Celsius.
However, the intravenous injection, the probability of transmission is very high - up to 95 . Registered cases of HIV transmission to medical personnel during injections needles. To reduce the likelihood of HIV transmission (up to fractions of a percent) in such cases, doctors prescribe a four-week course of highly active antiretroviral therapy. Chemoprophylaxis may be appointed, and other persons who have been exposed to infection. Chemotherapy is no later than 72 hours after the likely penetration of the virus.
Reuse of syringes and needles by drug addicts are likely to result in HIV transmission. To prevent this created a special charity items where addicts can get clean needles in exchange for used. Besides, young drug addicts is almost always sexually active and prone to unprotected sex, which creates additional preconditions for the spread of the virus.
Data about HIV transmission through unprotected sexual contact in different sources differ greatly. The risk of transmission largely depends on the type of contact (vaginal, anal, oral, etc.) and partner roles (bringing side/receiving side).
The risk of HIV transmission (per 10,000 unprotected sex)
for introducing a partner in fellatio is 0.5
for the receiving partner during fellatio - 1
for introducing a partner during vaginal sex - 5
for the receiving partner during vaginal sex - 10
for introducing a partner during anal sex is 6.5
for the receiving partner during anal sex 50
Protected intercourse in which condoms have broken or been broken its integrity, is considered unprotected. To minimize such cases, you need to follow the rules, condom use, and use reliable condoms.
It is also possible vertical transmission from mother to child. Prophylaxis with HAART, the risk of vertical transmission can be reduced to 1.2 .
The amount of the virus in other body fluids - saliva, tear - negligible - there is no information on cases of infection through saliva, tears, sweat. Breastfeeding can cause infection, as breast milk contains HIV, so HIV-positive mothers is not recommended to breast-feed babies.
HIV is not transmitted through
. the bites of mosquitoes and other insects,
. the air
. kiss (any),
. the dishes,
. use of bathroom, toilet, swimming pool, etc.
HIV primarily infects cells of the immune system (CD4 T-lymphocytes, macrophages and dendritic cells), as well as some other types of cells. HIV-infected CD4 T cells gradually die. Their deaths are mainly due to three factors
1. the direct destruction of cells by the virus
2. programmed cell death
3. the killing of infected cells by CD8 T-lymphocytes. Gradually, the subpopulation of CD4 T lymphocytes is reduced, resulting in cell-mediated immunity is reduced, and when the critical level of CD4 T lymphocytes, the body becomes susceptible to opportunistic (opportunistic) infections.
Once in the human body, HIV infects CD4 lymphocytes, macrophages and certain other cell types. Penetrated in these cell types, the virus becomes active to reproduce. This ultimately leads to the destruction and death of the infected cells. The presence of HIV eventually causes a disturbance of the immune system due to the selective destruction them immune cells and suppress their subpopulations. Released from cells viruses are being introduced in the new, and the cycle repeats. Gradually the number of CD4 lymphocytes decreases so that the body can no longer resist the causative agents of opportunistic infections, which are not dangerous or not dangerous for healthy people with normal immune systems.
The pathogenesis of HIV is still not very clear. Recent data suggest that hyperactivation of the immune system in response to infection is a major factor in the pathogenesis of HIV. One of the features of the pathogenesis of the loss of CD4 T cells (T helper cells), the concentration of which is slowly but steadily declining. Also decreases the number of dendritic cells, professional antigen presenting cells, which mainly develop an immune response to the pathogen that important consequences for the immune system is even more powerful factor than the loss of T helper cells. Causes of death of dendritic cells remain unclear.
Some of the causes of death of helpers:
1. Explosive reproduction of the virus.
2. Membrane fusion of infected and not infected helper cells with formation not viable simplastov(helper cells become sticky). Simplasty were found only in the laboratory under conditions of cell cultures.
3. Attack infected cells by cytotoxic lymphocytes.
4. Adsorption of free gp120 in infected CD4 helper cells with their subsequent attack by cytotoxic lymphocytes.
The main cause of death of T cells during HIV infection is programmed cell death (apoptosis). Even at the stage of AIDS, the level of infection of T4 cells is 1:1000, which suggests that the virus itself is not able to kill such a number of cells that are killed by HIV infection. To explain such a massive loss of T cells and cytotoxic effect of other cells.
Disorders in the immune system over time, grow up to a complete inability to perform its primary function of protecting the body from disease-causing organisms. Amid hyperactivation often have leukemia, which together leads to the fact that facultative parasites that coexist in a healthy organism under the control of the immune system are out of control, becoming disastrous for the body.
The main reservoir of HIV in the body - macrophages and monocytes:
1. In them exploding reproduction.
2. The output occurs via the Golgi complex.
The symptoms of HIV infection:
The incubation period (the time of seroconversion to the appearance of detectable antibodies to HIV) - period from infection to onset of reaction of the organism in the form of clinical manifestations of "acute infection" and/or antibody production. Its duration is usually from 3 weeks to 3 months, but in rare cases it may take up to a year. In this period there is an active HIV replication, however, the clinical manifestations of the disease and no HIV antibodies are not yet detectable. The diagnosis of HIV infection at this stage is on the basis of epidemiological and laboratory data must be confirmed by the detection in serum of the patient of the human immunodeficiency virus, its antigens, nucleic acids of HIV.
Stage 2. "The stage of primary manifestations" . During this period, active replication of HIV in the body is ongoing, but is already apparent initial response of the organism to the introduction of this agent in the form of clinical manifestations and/or antibody production. Stage of early HIV infection can occur in several forms.
2A. "Asymptomatic" when any clinical manifestations of HIV infection or opportunistic infections that develop on the background of immunodeficiency, absent. The body's response to the introduction of HIV appears only the generation of antibodies.
2B. "Acute HIV infection without secondary diseases" can manifest a variety of clinical symptoms. Most often this fever, rash (urticarial, papular, petechial) on the skin and mucous membranes, lymphadenopathy, pharyngitis. There may be enlargement of the liver, spleen, diarrhoea. In the blood of patients with acute HIV infection can be detected shirokoplazmennye lymphocytes ("mononuclear cells").
Acute clinical infection is seen in 50-90 infected persons in the first 3 months after infection. The beginning of the period of acute infection usually precedes seroconversion, i.e. the appearance of antibodies to HIV. At the stage of acute infection often there is a transient decrease in the level of CD4 lymphocytes.
2B. "Acute HIV infection with secondary diseases" . In 10-15 of patients with acute HIV infection on the background of reducing the level of CD4 lymphocytes and developed as a consequence of immunodeficiency appear secondary diseases of different etiology (tonsillitis, bacterial and Pneumocystis pneumonia, candidiasis, herpes 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. The vast majority of patients the initial stage of HIV infection enters a latent stage.
Stage 3. "Latent" . Characterized by slow progression of immunodeficiency, compensated for by modification of the immune response and excessive reproduction of CD4 cells. In the blood are antibodies to HIV. The only clinical manifestation of the disease is an increase of two or more lymph nodes in at least two unrelated groups (excluding inguinal).
Lymph nodes are usually elastic, painless, not soldered to the surrounding tissue, the skin over them is not changed.
Duration of the latent stage can varirovat from 2-3 to 20 years or more, and an average of 6-7 years. In this period there was a gradual decline of CD4-lymphocytes, on average, at a rate of 0.05-0,07x109/l per year.
Stage 4. "Stage of secondary diseases" . Ongoing HIV replication, leading to the death of t cells and depletion of populations, leads to the development on the background of immunodeficiency secondary (opportunistic) diseases, infectious and/or Oncology.
Depending on the severity of secondary diseases isolated stage 4A, 4B, 4C.
In the stage of secondary diseases emit phase progression (in the absence of antiretroviral therapy or antiretroviral therapy) and remission (spontaneous or background antiretroviral therapy).
Stage 5. "End-stage" . In this stage the available in patients with secondary disease become irreversible for. Even the adequacy of antiviral therapy and therapy is secondary diseases not effective and the patient dies within a few months. For this stage is typically a reduction in the number of CD4 cells is below 0,05x109/L.
It should be noted that the clinical course of HIV infection is very varied. The sequence of progression of HIV infection through the completion of all stages of the disease is not mandatory. The duration of the course of HIV infection varies widely - from several months to 15-20 years.
Consumers of psychoactive substances the disease has some features. In particular, fungal and bacterial lesions of the skin and mucous membranes, and bacterial abscesses, cellulitis, pneumonia, sepsis, bacterial endocarditis may develop on the background of normal CD4 lymphocytes. However, the presence of these lesions contributes to more rapid progression of HIV infection.
Clinical features of HIV infection in children
The most frequent clinical manifestation of HIV infection in children is the delay of rates of psychomotor and physical development.
In children more often than adults, meet recurrent bacterial infections and lymphoid interstitial pneumonitis and pulmonary hyperplasia of lymph nodes, encephalopathy. Often thrombocytopenia, clinically manifested hemorrhagic syndrome, which can cause death in children. Often develop anemia.
HIV infection in children born to HIV-infected mothers, characterized by a more rapidly progressive course. In children infected at age older than one year, the disease usually develops more slowly.
Diagnosis of HIV infection:
The course of HIV infection is characterized by prolonged lack of significant symptoms. The diagnosis of HIV infection is based on laboratory data: the detection of antibodies to HIV (or direct detection of the virus!). Antibodies to HIV during the acute phase, usually do not detect. In the first 3 months. after infection, antibodies to HIV appear in 90-95 patients after 6 months. - the rest of 5-9 and at a later date - only 0,5-1 . In the AIDS stage register a significant decrease in the content of antibodies in the blood. The first weeks after infection represent a "period seronegative window" when HIV antibodies are not detected. Therefore, a negative result of HIV testing in this period does not mean that the person is not infected with HIV and can infect others.
Virus isolation is not carried out in practice. In practice the more popular methods of detecting antibodies to HIV. Originally antibodies detected by ELISA. A positive result of ELISA serum examined by the method of immune blot (blot). It allows you to detect specific antibodies to the particles of the protein structure of HIV with a well defined molecular weight. The most characteristic of HIV infection is considered antibodies to HIV antigens with a molecular weight of 41 000, 120 000 and 160 000. When identifying final diagnosis.
A negative result of immunoblotting in the presence of clinical and epidemiological suspicion of HIV infection does not reject the possibility of this disease and must be repeated laboratory tests. This is due, as already mentioned fact that in the incubation period of the disease antibodies yet, and in the terminal stage, due to depletion of the immune system, they are no longer produced. In these cases, the most promising polymerase chain reaction (PCR) to detect particle RNA virus.
At diagnosis of HIV infection is carried out multiple research of the immune status in dynamics to monitor disease progression and treatment effectiveness.
For the diagnosis of lesions of the oral mucosa in HIV-infected patients accepted classification adopted in London, in September 1992. All lesions were divided into 3 groups:
. Group 1 - destruction, 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 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 infection-
o diseases of the salivary glands-
o viral infections-
o thrombocytopenic purpura.
. Group 3 - lesions that can be HIV, but not related.
Of greatest interest are the most frequently encountered lesions belonging to group 1.
In Ukraine in the diagnosis of HIV infection is carried out pre-test and post-test counseling of the patient, explaining the key facts about the disease. The patient is asked to register with the territorial center for prevention and fight against AIDS for a free follow-up care as an infectious disease physician. Approximately every six months is recommended to get tested (for immune status and viral load) to monitor health status. In the case of significant deterioration of these indicators, it is recommended the use of antiretroviral drugs (therapy free, available in almost all the regions).
Treatment of HIV infection:
To date not developed for the treatment of HIV infection, which could eliminate HIV from the body.
The modern method of treating HIV infection (the so-called highly active antiretroviral therapy) slows down and almost stops the progression of HIV infection and its transition to the stage of AIDS, allowing HIV-infected person to live a full life. When using treatment and provided that the effectiveness of drugs is maintained, the duration of human life is not limited to HIV, but only the natural aging process. However, after prolonged use of the same regimen in a few years, the virus will mutate, acquiring resistance to the drugs, and to further control the progression of HIV infection is necessary to apply new regimens with other drugs. Therefore, any existing treatment regimen for HIV infection sooner or later becomes ineffective. Also, in many cases, the patient may not take certain drugs because of individual intolerance. Therefore, careful application of therapy delays the development of AIDS indefinitely. To date, the emergence of new classes of drugs has focused mainly on the reduction of side effects from treatment, as the life expectancy of HIV positive people receiving therapy almost on par with the life expectancy of HIV-negative population. In the later period of the development of HAART (2000-2005) the survival of HIV infected patients by excluding patients with hepatitis C reaches to 38.9 years (37,8 – for men and 40.1 per for women).
Great importance is attached to maintaining the health of HIV-positive non-drug means (proper food, good sleep, avoiding severe stress and prolonged exposure to the sun, a healthy lifestyle), and regular (2-4 times a year) monitoring of the health status of medical specialists on HIV.
Resistance (immunity) to HIV
A few years ago was described a genotype resistant to HIV. The penetration of the virus into the immune cell linked with its interaction with surface receptors: CCR5 protein. But a deletion (loss of a portion of a gene) CCR5-Delta leads to its bearer immunity to HIV. It is assumed that this mutation arose approximately two and a half thousand years ago and eventually spread to Europe.
Now HIV is actually sustainable on average 1 Europeans, 10-15 Europeans have partial resistance to HIV.
Scientists at the University of Liverpool explain this irregularity is the fact that the CCR5 mutation increases resistance to bubonic plague. So after the epidemics of the black death 1347 year (and in Scandinavia and 1711) proportion of this genotype increased.
There is a small percentage of people (about 10 of all HIV-positive), in the blood contain the virus, but AIDS is they do not develop for a long time (so-called noprogressbar).
Discovered that one of the main elements of antivirus protection of man and other primates is the TRIM5a protein, is able to recognize the viral capsid particles and prevent the virus from reproducing in the cell. This protein in humans and other primates has differences that determine innate resistance of chimpanzees to HIV and related viruses, and the human innate resistance to PtERV1 virus.
Another important element of antivirus protection - interferon-induced transmembrane protein CD317/BST-2 (bone marrow stromal antigen 2), which also received the name "tetherin" for its ability to inhibit the allocation of the newly formed subsidiary of virions through their retention on the cell surface. CD317 - transmembrane protein of the 2nd type with unusual topology - transmembrane domain near the N-end and glycosylphosphatidylinositol (GPI)-end - between them there is an extracellular domain. It is shown that CD317 interacts directly with a Mature child virions, "tying" them to the cell surface. To explain the mechanism of such "tying" the proposed four alternative models, according to which two CD317 molecules form parallel C) an homodimer - one or two homodimer contacted simultaneously with a single virion and cell membrane. With the virion membrane or interact both membrane anchor (transmembrane domain and GPI) is one of the CD317 molecules, either one of them. Spectrum of activity CD317 includes at least four families of viruses: retroviruses, filoviruses, arenaviruses and herpesviruses. The activity of this cellular factor is inhibited Vpu proteins of HIV-1, Env HIV-2 and SIV, SIV Nef, a membrane glycoprotein of the Ebola virus and the K5 protein of the herpes virus Kaposi's sarcoma. Found cofactor protein CD317 - cell protein SA (Breast cancer-associated gene 2 - Rabring7, ZNF364, RNF115) - E3 ubiquitin ligase class RING. BCA2 enhances the internalization of virions of HIV-1 associated protein CD317 to the cell surface, in intracellular CD63 vesicles and their subsequent degradation in the lysosomes.
CAML (calcium-modulated cyclophilin ligand) is another protein, which, like CD317, inhibits the release of adult child of virions from the cell and the activity of which is inhibited by the Vpu protein of HIV-1. However, the mechanisms of action of CAML (a protein localized in the endoplasmic reticulum) and antagonism by Vpu is unknown.
People living with HIV
The term "People living with HIV" (PLHIV) is recommended in respect of the person or group of people who are HIV-positive status, as it reflects the fact that people can live with HIV for decades, leading an active and productive lifestyle. Extremely incorrect is the expression "AIDS victims" (this implies helplessness and lack of control), including incorrect naming children with HIV "innocent victims of AIDS" (this implies that someone of PLHIV "to blame" in their HIV-status or "deserve" it). The expression "AIDS patient" is valid only in a medical context, because PLHIV do not spend their lives in a hospital bed. Rights of HIV positive people are no different from the rights of other citizens: they also have the right to medical care, freedom of work, to education, to personal and family privacy and so on.
Prevention of HIV infection:
The who distinguishes 4 main areas of activities aimed at combating the epidemic of HIV infection and its consequences:
1. Prevention of sexual transmission of HIV, including such elements as teaching safe sex practices, distribution of condoms, treatment of other sexually transmitted diseases, training, behavior, conscious aiming at the treatment of these diseases
2. Prevention of HIV transmission through blood, through the supply of safe drugs made from blood.
3. Prevention of perinatal transmission of HIV methods of disseminating information on the prevention of transmission of HIV by providing medical care, including counselling of HIV-positive women, and holding chemoprophylaxis-
4. The organization of medical care and social support to patients with HIV, their families and others.
Sexual transmission of HIV can be stopped by training people in safe sex practices, and hospital - adherence to anti-epidemic regime. Prevention includes proper sexual education of the population, prevention of promiscuity, promotion of safe sex (using condoms). Specific directions for prevention work among drug users. Because to prevent HIV infection among drug addicts is easier than to save them from drug addiction, it is necessary to explain the methods of prevention of infection in injecting drug users. The decrease in the prevalence of drug addiction and prostitution is also included in the system of prevention of HIV infection.
For the prevention of HIV transmission through blood conduct examination of donors of blood, sperm, organs. To prevent contamination of the children to be tested for HIV pregnant. Patients with STDs, homosexuals, drug addicts, prostitutes are examined mainly for surveillance purposes.
Anti-epidemic regime in hospitals is the same as in viral hepatitis b, and includes ensuring the safety of medical manipulations of donor blood, medical immunobiological preparations, biological fluids, organs and tissues. Prevention of HIV infection of medical personnel is reduced mainly to the observance of rules of work with cutting and piercing instruments. In case of contact with HIV-infected blood is needed to treat the skin 70 alcohol, wash with soap and water and reprocess 70 alcohol. As a preventive measure, consider taking azidothymidine within 1 month. Exposed to the threat of infection is under the supervision of a technician within 1 year. Means of active prevention is still not developed.
Pregnant HIV-infected prescribed for administration of antiretroviral drugs in the last months of pregnancy and during labor to prevent the birth of HIV-infected child. Children born to HIV-infected mothers in the first days of life also appoint receiving antiretroviral funds, they are immediately transferred to artificial feeding. This set of measures can reduce the risk of having an infected child with up to 25-50 3-8.