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The virus of the human immunodéficience ( HIV , English HIV) is a Rétrovirus infecting the man and leading it to more or less long run with the Syndrome of acquired immunodéficience (AIDS), which is a weakened state of the Immune system which makes it vulnerable to multiples opportunist infections.

Transmitted by several body fluids: Blood, vaginal secretions, Sperm or Mother's milk, the AIDS is today regarded as a Pandémie successor in title the death of approximately 25 million people between 1981 (date of the first identification of case of AIDS) and January 2006. It is estimated that approximately 1 % of the elderly from 15 to 49 years live with the HIV, mainly in sub-Saharan Africa.

Although there exist treatments antirétroviraux fighting against the HIV and delaying by consequence the appearance of the AIDS, thus reducing the Mortalité and the Morbidité, there does not exist at present any vaccine or final treatment. The prevention, which passes in particular by the sexual relations protected and the knowledge from its statute serologic so as to avoid the infections of others is the most effective means of the fight.

History

The epidemic of AIDS is discovered the June 5th 1981 by CDC of the the United States after the advertisement of a recrudescence in the towns of Los Angeles, San Francisco and New York of case of Pneumonie S with Pneumocystis carinii and of sarcomes of Kaposi. These two diseases have as a characteristic to infect the immunodéprimées people . The first patients all are homosexual with the result that this syndrome, which did not bear yet the name of AIDS, is called the gay syndrome or gay cancer . But in the months which follow, other people are infected, of the drug addicts by injections and the hemophiliacs, showing thus that the blood way, in addition to sexual is the mode of contamination.

The viral origin is privileged, have regard to the modes of transmission then identified. Several viruses are blamed, but one realizes that they are only one consequence. The first human Retrovirus discovered, HTLV-1, is regarded as the cause of the AIDS by the American team directed by Robert Gallo which had discovered it in 1980.

Starting from 1982, with the first cases identified in France, French research begins. Willy Rozenbaum, doctor with the Hospital Bichat of Paris, wants to encourage the researchers to study the AIDS ahead and to find the cause of it. Via Francoise Brown-Vezinet, a colleague doctor, Willy Rozenbaum meets Jean-Claude Chermann, Francoise Barred-Sinoussi and Luc Montagnier of the unit viral Oncologie of the Institut Pasteur. The latter agree to begin research and in January 1983 Willy Rozenbaum sends a sample of a patient reached of Lymphadénopathie which is identified as an opportunist disease of the stage chaired. The sample is put in culture and an activity of Transcriptase reverses is identified confirming the presence of a retrovirus. Quickly a Apoptose appears, the addition of white globules to the setting in culture starts again the opposite activity of transcriptase then. An examination with the Electron microscope made it possible to visualize for the first time the virus.

After a making of contact with Robert Gallo for an information exchange, the team of the Pasteur Institute confirms that the virus identified at the patient lymphadenopathic is not the HTLV-1. This new retrovirus is then called Lymphadenopathy Associated Virus (LAV) and the results are published in Science on May 20th, 1983. At this stage the bond between the LAV and the AIDS is not clearly established by the team of Luc Montagnier. The team of Robert Gallo publishes on May 4th, 1984 in Science the results of the insulation of a virus which she regards as person in charge of the AIDS and names it HTLV-3. The team of Jay A. Levy with San Fransisco makes in the same way on August 24th, 1984 and names it AIDS-associated retroviruses (ARV). During a time, the three denominations cohabit and a polemic has during a time existed between the teams American and Frenchwoman concerning the anteriority of the discovery.

The LAV is studied under all the aspects and several points are then shown, like the fact that it is completely different from the HTLV-1 which is a Oncovirus pushing the lymphocytes T to be multiplied, whereas the LAV kills them. With the co-operation of the CDC, the team of the Institute Pasteur reinforces the assumption more and more that the HIV is the cause of the AIDS, which is regarded today as a fact by the scientific community. In January 1985, the sequencing of the LAV is carried out by a team of the Pasteur Institute which publishes its results in Cell . It is this same year that is confirmed that three viruses (LAV, HTLV-3 and ARV) are the same ones.

The first Test HIV are marketed during the year 1985.

The July 18th 1986 are published in Science by the team of Luc Montagnier, in collaboration with doctors Portuguese, the results of the study of a patient coming from West Africa. The examinations made it possible to identify a new type of LAV, the LAV-2. The sequencing of the new virus is carried out the following year, as well as the development of a screening test.

In 1986, the LAV (as well as the other denominations) is officially famous in virus of the human immunodéfience (HIV), the LAV-1 becomes VIH-1 and the LAV-2, VIH-2.

The international community becomes aware of the gravity of the epidemic which is transformed quickly into Pandémie and thus on October 26th, 1987 the General meeting of the United Nations vote a resolution inviting all the States and all the U.N. agencies to cooperate to fight against this pandemia. Since the fight against VIH/Sida became a priority for UNO through its program Onusida, like many governments. The scientific community is also very active in order to develop a vaccine, making HIV the virus more studied to date.

Although AZT was used as of 1986 to fight against the HIV, it will be necessary to await the medium of the Années 1990 so that arrive on the market of the really effective treatments against the replication of the HIV. These treatments, called Trithérapie S, combine several drugs at the same time to fight the HIV on several faces. The biological development of test making it possible to estimate the Viral load largely took part in the effectiveness of these treatments, because making it possible consequently to modify the trithérapie to make it possible most effective.

Structure

The HIV is a Rétrovirus kind of the Lentivirus which are characterized by long a Incubation period and consequently a slow evolution of the disease (from where the root of the name coming from the Latin lenti , meaning slow).

It is of an overall spherical aspect for a varying diameter from 90 to 120 Nanomètre S. Like many viruses infecting the animal, it has an envelope made up of the remainders of the membrane of the infected cell. This envelope is covered with two types of Glycoprotéine S: the first is the gp41 which crosses the membrane, the second is the gp120 which recovers the part of the gp41 which leaves the membrane. A very strong connection exists between the gp120 and the receiving of the markers CD4 present at the surface of the cells CD4+ of the immune system. For this reason the HIV infects only cells having this receiver on their surface, which are in very great majority lymphocytes CD4+.

Inside the envelope is a proteinic matrix made up of proteins p17 and still inside the Capside made up of proteins p24. It is the latter type of proteins, with gp41 and gp120, which is used in the tests HIV Western blot. The Nucléocapside is made up as for it of proteins p6 and p7.

The genome of the HIV, contained in the capsid, consists of a simple bit of ARN in double specimen accompanied by Enzyme S which:

transcribes the viral ARN in viral DNA, it is the Transcriptase reverses p64
integrates the viral DNA into the cellular DNA, it is the Intégrase p32
takes part in the assembly of the virus, it is the Protéase p10. The latter is not present in the capsid, but fleet in the matrix p17

These three enzymes are the main targets of the antirétroviraux treatments, because specific to the retroviruses.

The genome of the HIV is composed of nine genes. The three principal ones are gag , pol. and env which defines the structure of the virus and are common to all the retroviruses. The six other genes are tat , rev , nave , sharp , vpr and vpu (or vpx for VIH-2) which codes regulating proteins and whose functions are not known with precision.

Transmission

The HIV is present in many organic fluids. One found some in the Salive, the Larme S and the Urine, but in insufficient concentrations so that cases of transmission are recorded. The transmissions by these fluids is thus regarded as negligible. On the other hand, of the rather large quantities of HIV for an infection were detected in the Sang, the Mother's milk, the cyprine, the Sperme, as well as the liquid preceding the ejaculation.

Consequently, the three modes of contaminations are:

the not protected sexual relations, which they are heterosexuals or homosexual represents the most significant part of the contaminations
the contact with material contaminated at:

the drug addicts by injection
transfused
the health workforce

the transmission mother-child during the Pregnancy, during the Childbirth and at the time of the Breast feeding. Without treatment and with a natural childbirth the rate of transmission varies, according to the studies, between 10 and 40 %. It is during the childbirth that the risk of infection are highest (65 % of all the cases of infection). A treatment and the practice of a Césarienne can cause a drop in this figure with 1 %.

Cycle replication

The target cells of the HIV are those presenting of receiver CD4 to their surface. Thus, the lymphocytes T CD4+, the Macrophage S, the dendritic cells and the cerebral cells microgliales can be infected by the HIV. Thus, the viral replication takes place in several fabrics.

The replication of the virus is held in several stages:

; Fixing or attachment with a cell This stage rests on a recognition between proteins of viral surface gp120 and receivers CD4 of the target cell. After the union with a receiver CD4, gp120 changes Conformation and is attracted towards a Co-receiver also having to be present beside molecule CD4. More than one ten Co-receiver were identified, but the principal ones are CXCR4 for the lymphocytes T CD4+ and CCR5 for the macrophages.

; Fusion, the penetration and the decapsidation It is the second stage of the infection intervening just after the union of gp120 with the Co-receiver. This union releases the protein gp41 which sets on the cytoplasmic membrane. By return to itself, gp41 attracts the viral envelope towards the cytoplasmic membrane and the fusion of the membranes cellular and viral takes place thanks to a Peptide of fusion presents in gp41. The capsid of the HIV penetrates then in the Cytoplasme of the cell, once inside the cell, it disaggregates releasing the two bits of ARN and the enzymes which it contained.

Thus, the protein gp120 is responsible for the attachment and gp41 for fusion then penetration within the cell. ; The opposite transcription This stage is specific to the retroviruses. The latter having for genome of the ARN and not of the DNA, an operation of transcription, " convertissant" the viral ARN in viral DNA is necessary. Because only of the DNA can be integrated in the genome of the target cell. This transcription is carried out by the enzyme of Transcriptase reverses (TI). TI course the viral ARN and transcribes it in a first molecule of DNA simple-chain, or DNA bit (-). During this synthesis, the ARN matrix is degraded by an activity known as " RNAse H" range by TI. The degradation of the ARN is total except for two short sequences rich in purins called sequences Pt (polypurine leaflets). These two short sequences will be used as starters with TI for the synthesis of the second bit of DNA, the bit (+), by using the DNA bit (-) like matrix. The final DNA is a molecule bicaténaire also called DNA in double-bit. A characteristic of the opposite transcriptase is not to be faithful in its transcription and often makes errors. This is why the HIV has a very large genetic variability.

; Integration The DNA bicaténaire penetrates in the cellular core according to an active process still badly included/understood. This nuclear importation constitutes a characteristic specific to the lentivirus which are in fact able to infect cells in stationary phase, i.e. whose core is intact. With this intention, the DNA bicaténaire is at this time cycle closely associated with the intégrase and other viral and cellular proteinic components in a complex called complex of pre-integration. This complex has the capacity to interact with elements of the nuclear membrane to cross this membrane and to reach cellular chromatin. The DNA is integrated then randomly in the genome of the target cell under the effect of the enzyme Intégrase.

; Formation of a ARN messenger The two bits of DNA of the cell “deviate” locally under the effect of the ARN polymerase. Free nitrogenized bases of the core come to take the complementarity of the sequence and are polymerized in a chain monobrin: ARNm (messenger).

; The épissage ARNm thus obtained is heterogeneous. Indeed, it consists of a succession of will introns (parts not coding) and of let us exons (coding parts). This ARNm must undergo a maturation to be able to be read by ribosomes. An excision does without then will introns, not to leave that exons them.

; Translation of the ARN Once left the core by one of the nuclear pores, ARNm is read by ribosomes of the RER (rough endoplasmic reticulum). ARNm comes in fact to slip between the two pennies units of ribosome. For each codon (group of three nucleotides) of ARNm, ribosome will allot an amino-acid. Those will polymerize reading progressively. A codon initiating AUG (Adénine-Uracil-Guanine) will make begin the synthesis while a codon stop (UAA; UGA; UAG) will mark the end of it.

; Maturation It takes place in the Appareil of Golgi: Polypeptides thus formed are not yet operational. They must undergo a maturation in the apparatus of Golgi.

; Assembly The proteins of structure of the virus (matrix, capsid and nucléocapside) are produced in the form of polyprotéines. When they leave Golgi, the various proteins are dependant between them. The proteins are transported to the membrane where they join the membrane viral glycoprotéines. Viral ARN join viral proteins. The proteins of structure are assembled to form the capsid and the matrix, including this unit. ; Budding The capsid leaves the cell infected by tearing off part of the cellular membrane (at which the viral proteins of surface (gp120 and gp41) were fixed beforehand).

; The maturation of the viruses A viral protease must cleave the bonds which link various proteins of structure (matrix, capsid and nucléocapside) so that the virions are infectious. Following cleavages, the virions are ready to infect new cells.

Genetic variability

The HIV is a virus which has a very important genetic variability and thus has a very great diversity. Two types were discovered:

the VIH-1, most present in the world
VIH-2, less contagious than VIH-1 and prevails mainly in West Africa

Within each type exist several groups, which in their turn comprise sub-types. One explains this great genetic variability of the HIV by several mechanisms:

the Transcriptase reverses, which makes it possible the HIV to be retorted, is an enzyme not having a mechanism of detection of the transcription errors. The errors are thus frequent and were estimated at all them: 1700 with: 10000 Nucleotide S produced. As the genome of the HIV is composed of a little less: 10000 nucleotides, there is roughly between one and 10 changes with each viral cycle,
the big number of produced Virion S, which is about: 10000 per day for each virions infecting a cell.

The transcription errors produce many virions different from/to each other. The majority of these changes involve the production of virions unable to correctly retort, what intends them to disappear, lethal changes. Thus the Natural selection is carried out. This important disappearance of virions is compensated by the great number of produced virions. The surviving virions, although different and representative what one names a Quasi-species, have all the characteristic to be perfectly adapted to their medium. That results in to see appearing virions resisting the immunizing response of the organization, which leads to more or less short term in a state immunodéprimé of the organization if the rate of lymphocytes CD4+ is too low.

The catch of a medicamentous treatment by the patients infected by the HIV also involves a selection within the viral population, thus tending towards the appearance of virions resistant to the drugs. The development of multithérapies aims to attack the HIV on several aspects and thus to limit the possibilities of the virus of adapting to its medium.

The important variability of the HIV involved the appearance of several variable, which made that since 1998 the VIH-1 is classified in three groups, of which each one would correspond to transmissions independent of SCREW _cpz of the chimpanzee to the Man:

group M (for major group )
group O (for outlier group )
group NR (for non-M, non-O group )

The group M prevails largely with more than 40 million contaminated people, against a little more than 500 for the group O and only 7 for the group NR.

The group M includes/understands nine sub-types or Clade S (of has to D, of F with H, J and finally K). To that is added several recombining forms (in English circulating recombining form or CRF), who originate in it multiple infection of a cell by different sub-types, which involves mixtures in the genome viral.

The sub-types and recombining forms of the group M are not distributed uniformly on all planet. Thus, in Europe, in Americas and in Australia it is the sub-type B which is most present, whereas in Africa it is according to the areas has and C and in Asia, always according to the areas, the groups C and E.

Although genetic variability within the same group does not seem significantly to modify the pathogenicity and the progression of the infection, it poses all the same serious problems for the development of a effective vaccine on all the groups and stocks of the HIV, for measurements of the viral load and in certain particular cases of Test HIV. In this last case, thus the screening tests based on antigens of the VIH-1 of sub-type B and VIH-2 of sub-type has, can have a less sensitivity for the recognition of the other sub-types, particularly at the time of the primary infection or infection by the variable ones like the VIH-1 of the group O.

Infectious diagnosis and follow-up

Diagnosis

The diagnosis aiming at determining the statute serologic with the HIV is carried out in two stages:

the Dépistage , in the method of reference that passes by a detection of antibodies anti-HIV
the confirmation that the detected Anticorps are quite related to an infection by the HIV

The first stage is based on the detection of antibodies produced in answer to an infection by the HIV, they are antibodies anti-HIV. This production of antibody can be detected with the current means on average 22 days after the contamination. During this period, called serologic window, the patient is perfectly infectious, which poses obvious problems of Public health. Once the last serologic window its statute serologic can be established.

The first stage of detection employs the method ELISA, which uses the reaction antibody-antigen to detect the presence of antibodies anti-HIV. To avoid the negative forgeries and thus not to pass beside a case of seropositivity, the test must have a optimal sensitivity, a mixture of viral Antigène S is then used, allowing the detection of antibodies anti-HIV-1 and anti-HIV-2 (one speaks then about mixed ELISA). The use of two commercial tests of origin different is generally carried out to eliminate the maximum of false-positives as of the first stage.

If detection appears positive, doubtful, or unmatched, a confirmation is carried out. The latter aims at knowing if the detected antibodies are quite related to an infection by the VIH-1. For that one uses a specific method , from which the goal is to eliminate the wrongfully positive results. It is the method Western blot (WB) which is generally utilisée. There still, if the test is doubtful or indicates a beginning of seroconversion, a second test of confirmation is carried out later three weeks, time to wait until the seroconversion is complète.

confirmation of the seroconversion with the VIH-1

seropositivity with the VIH-2 (which must be again confirmed by a test specific to the VIH-2)

reaction nonrelated to the HIV (what arrives in more the share of the cases)-->

It is only following the whole as of these tests that a doctor will be able declared a patient HIV positive.

Other methods

There exist other techniques of detection of an infection by the HIV, like:

the antigénie p24: useful when the seroconversion did not take place completely yet. The test becomes negative once the seroconversion carried out, that thus explains the use of the procedure previously described like a standard
the combined method: who uses the antigénie p24 and the detection of antibody. This method is interesting with the whole beginning of the contamination, because it reduces the serologic window up to two to five days, while ensuring the taking into account of the people completely séroconvertis
insulation in culture: used for the newborns of HIV positive mother, because the latter are obligatorily HIV positive, the antibodies of the mother having been transmitted. The infection is confirmed when an opposite activity of transcriptase is detected or many antigens p24.
the detection of the viral ARN: one seeks the genes gag or pol. of the HIV. This method tends to replace the method of insulation by culture for the newborns

Infectious follow-up

Once established seropositivity, a regular follow-up of the infection must be carried out to ensure a good assumption of responsibility of the disease and thus to evaluate the state of the patient as well as possible. Two factors are taken into account:

the rate of lymphocytes T₄, to define the level of the infection
the viral load, indicating the number of virion in the organization, consequently the speed of replication of the HIV in the organization and thus allowing to predict the evolution of the infection

The rate of T₄ lymphocytes measures the immunizing deficit caused by the presence of the HIV. This numeration corresponds to the number of T₄ cells present in blood. A normal level at the Man ranges between 600 and: 1200 T₄/mm. One considers that:

until 500/mm the patient can live under normal conditions and does not require treatment
starting from 350/mm the patient must absolutely receive an antiviral treatment cause a drop in the viral load and to make go up its rate of T₄
in lower part of 200/mm it is immunodéprimé and is very strongly likely to suffer from opportunist multiples diseases related to the AIDS, there also, the patient must be placed under treatment

The difference between two measurements of viral load spaced in time makes it possible to evaluate the speed of replication of the HIV and consequently the progression of the infection. There is a direct link between the viral load and the level of the immunizing deficit, caused principalment by the disappearance of the T₄ lymphocytes. The viral load is defined by measuring the concentration of the viral ARN in blood. This measurement can vary largely according to the methods employed, for this reason is it is important that all the evaluations of viral load are carried out in the same laboratory with the same technique. It is the log₁₀ number of copies/ml which is used to evaluate the variation in the time of the viral load. A higher variation or equalizes to 0,5 is significant. This replication is stabilized after a few weeks on a more or less important level according to the subjects. The hyperactivé immune system compensates for partially the massive destruction of the lymphocytes T CD4+ by increasing their production, but the infection with HIV persists despite everything, with for consequence emergence and the selection of mutant viruses which escape the answer immune from the host.

Researchers of CNRS, Institute Curie and Pasteur Institute discovered that the virus modified pH cellular compartments where it accumulates in the macrophages, thus preventing the activation of the enzymes charged to degrade it.

During several years, the lymphocytes T CD4+ seem to be renewed quickly in spite of their destruction by the virus, until the exhaustion of the central lymphoid bodies (thymus) does not allow any more their regeneration. The destruction of the lymphocytes T CD4+ is very often due to the hyperactivation of these cells by interaction with certain structures of the virus and not to a direct destruction by the HIV. The effectiveness of the antirétroviraux treatments is evaluated by the level of viral replication measured by viral load HIV (rate of plasmatic ARN), the measurement of rate of lymphocytes T CD4+ (immunodepression) and by the clinical state of the patient.

Long-term Non-progressor

Several cases of HIV positive people succeeded in naturally keeping during one long life (at least 8 years) (i.e. without treatment) a rate of normal CD4 (higher than 500/mm ³) and a low viral load, even undetectable for some. But all ended up reaching the Sida stage. Longest remained 18 years in an asymptomatic state. These people are known as in the long run long-term or asymptomatic non-progresseurs (ALT).

There does not exist single model, certain patients remain in an asymptomatic state without significant evolution of their state, others know a slow deterioration of their immune system.

Epidemiology

Each year there is approximately 4,3 million new infections. In 2006 there was 39,5 million people living with the virus of the human immunodéficience, the majority being in sub-Saharan Africa and 2,9 million died of the AIDS.

In France, for the year 2005, the National Sanitary Surveillance Institute estimates at approximately: 6700 new cases of seropositivity (stable figure since 2003). The heterosexuals reports/ratios represent half of these new cases and concern for half of the people of sub-Saharan Africa. Between 2003 and 2005, the number of discovered seropositivity fell among women but increased at the homosexual ones who represent 27 % of the new cases of seropositivity. The proportion of infections with VIH-2 is of 1,4 % in 2005. Among the infections with VIH-1, the proportion of sub-types non-B decreased between 2003 and 2005 (of 50 % with 41 %). In 2005,5,3 million serologies HIV were realized, that is to say an increase in 8 % compared to 2004, while the number of positive confirmed serologies was stabilized.

Treatments

The antirétroviraux, which constitutes the therapeutic arsenal against the HIV, is packed day in day. The purpose of a score of antirétroviraux drugs are available in 2006 and are to interfere on various mechanisms, on the one hand on the enzymes of the HIV necessary to its replication and on the other hand on its mechanisms of entry in the cell.

Thanks to the Trithérapie used since 1996, the Mortalité due to the Sida fell to a significant degree everywhere where these new treatments were available . Thus in the United States the use with large scales of trithérapies with fact of passing the number of deaths each years of: 49000 in 1995 with approximately: 9000 in 2001.

These drugs can have side effects passengers or permanent which can lead to the stop or especially the modification of the treatment knowing that correctly followed they have a relatively important effectiveness.

Antirétroviraux

Inhibiters of the opposite transcriptase

See also: Inhibiting of the opposite transcriptase

The inhibiters of the opposite transcriptase prevent the synthesis of DNA proviral (i.e. which will allow the duplication of the virus) starting from the viral ARN. One finds in this class:

; Inhibiters nucleosidic (INTI) INTI constituted the first class of antirétroviraux marketing in 1985. They include/understand the Zidovudine (AZT) (synthesized in 1964), the Didanosine (ddI), the Zalcitabine (ddC), the Stavudine (d4T), the Lamivudine (3TC) (1989 and used starting from 1995), the Abacavir (ABC), and the Emtricitabine (CTF).

The changes of the genome because of the opposite transcriptase confer on the HIV a resistance to the INTI which can be cross between several INTI. These compounds all are neutral or reducing, except for the AZT which is oxidizing.

; Inhibiters nonnucleosidic (INNTI) INNTI are powerful and very selective inhibiters of the opposite transcriptase of the HIV. One finds in this class: the Nevirapine and the Efavirenz. They are active only on the VIH-1. It are metabolized in phenol S by oxidation.

; Analogues nucleotidic Nucleotidic Similar as the Ténofovir which was put on the market in 2002, are organophosphorés compounds.

Inhibiters of the protease

Inhibiters of intégrase

Inhibiters of fusion and entry

See also: Inhibiting of entry, Inhibiting of fusion

The inhibiters of fusion-lysis intervene at the time of the penetration and block the protein gp41 preventing it from binding to the cytoplasmic membrane.

Several products are being studied and only the Enfuvirtide received an authorization of setting on the US market in 2003. Its mode of administration is injectable by subcutaneous way.

Therapeutic choice

Since the beginning of the Années 1990 of the Trithérapie S were born which can be prescribed according to the clinical stage, of the rate of Lymphocyte S T CD4+ and of the Viral load. This antirétroviral treatment currently includes/understands three drugs, in general two inhibiters nucleosidic of the opposite transcriptase, associated with an inhibiter of the proteases or an inhibiter nonnucleosidic of the opposite transcriptase, or sometimes with a third inhibiter nucleosidic of the opposite transcriptase (" trithérapies"). An inhibiter of fusion is possibly associated there.

There is no precise criterion for all the patients fixing the beginning of a treatment antirétroviral, this decision must be adapted to each patient. There exist some criteria all the same based on the number of lymphocytes T CD4+. Thus, when an HIV positive has a rate of CD4+ higher than 350/mm³, it is not necessary to begin a treatment. But under the bar of the 200/mm³, it is imperative to begin a treatment. The number of CD4 compared to the totals number of lymphocytes is also a criterion. Thus when the CD4+ represent less than 15% of all the lymphocytes, a risk of infection by opportunist diseases appears.

During a first treatment, the near total of the patients voyent their plasmatic viral load made undetectable in the first six months. This first treatment must be simplest and best the tolerated possible one. Because it is it not observance treatment which is the leading cause of the therapeutic failure.

Although the antirétroviraux treatments are very effective when they are well followed, the HIV is always present in the organization, only its multiplication east slows down and although undetectable in blood, this last, as well as sperm, remain contagious.

Prevention

There does not exist unfortunately effective vaccine. Only the condom offers an effective protection at the time of the sexual relations. The blood donations are the subject of a selection of the donors, systematic trackings and specific treatments. Also, the prevention is done by the use of syringes of single use on any occasion, in particular in the event of intravenous drug-addiction or substitute treatment.

Alternative assumptions

A small minority of scientists and activists call in question the bond between the HIV and the AIDS, even the existence even of the HIV, or the validity of current tests HIV. Recently, a marked person to have had not protected sexual relationships used these concepts like defense system. These disputes are not begun again by majority of members of scientific community, which shows these people to be unaware of the obviousness of the role of the HIV in the AIDS and to be a threat for the Public health by dissuading the population to be made test or the patients to be under antirétroviraux treatments which proved reliable.

These dissidents affirm that the official approach of the AIDS, which regards as acquired its causality rétrovirale, had as a consequence of the erroneous diagnoses, the appearance of a psychological terror and a certain form of racism, the use of toxic treatments and the wasting of public funds. These opinions are largely rejected, and are regarded as Pseudo-science by the majority of the members of the scientific community.

See too

Discrimination of the carriers of the HIV

Sources

'' the discovery of the virus of the AIDS in 1983 '', on the site of the Pasteur Institute (for the section History )
'' the retroviruses '', course of Anne Decoster (for the section History , Structure , Transmission , Cycle of replication , genetic Variability and Diagnosis and follow-up infectious )
'' Virologie '', course of Jean-Marie Huraux, Henri Agut, Anne-Marie Fillet, Vincent Calvez, Vincent Thibault, Agnes Gautheret-Dejean, Marcellin AsGeneviève, Claire Deback (for the section Structure , Transmission , Cycle of replication , genetic Variability and Diagnosis and follow-up infectious )
Chapter 26 of '' Biologie '' (for the section Cycle of replication )

References

External bonds

'' HIV Medicine '', delivers medical synthesizing knowledge on the treatments of VIH/Sida in 2006
the publications of Gallo and Popovic in " Science" in 1984
the first " jet" preceding publication
World AIDS Day 2005 - December 1
National Institute off Health: The Evidence that HIV causes AIDS
NIH Evidence Rebuttal
Interview with Kary Mullis butt HIV and AIDS (1994)
Medical Formation Continues on the HIV
Operating process of the virus
Intégration and expression mode of the virus by Georges Dolisi
Sida and HIV, carrying the virus in the world & challenges to take up - summary by GreenFacts of a report/ratio of ONUSIDA (2006)

Simple: HIV Zh-min-nan: HIV

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