HealthDiseases and Conditions

AIDS: Implications and Statistics

The human immunodeficiency virus, or Human immunodeficiency virus (HIV), belongs to the family of retroviruses and the genus Lentivirus. This genus includes representatives that cause various infectious diseases of the blood and immunodeficiency in mammals.

Origin and identification

This type is represented by two non-cellular agents - HIV-1 and HIV-2, capable of causing Acquired Immune Deficiency Syndrome (AIDS). However, these subspecies are characterized by the rate of development of the disease. It is believed that the second type of HIV-2 is less aggressive to the human immune system. It has become widespread in the countries of Asia, Europe, America and Africa.

A sensational discovery was published in the journal Science, when the presence of this infectious agent in the lymph nodes of a homosexual was found, which suffered from the above syndrome. DNA analysis showed that these two subspecies of human immunodeficiency viruses have different origins. The closest relative of HIV 1 was a virus that caused the development of immunodeficiency in monkeys, later they were considered as subspecies of one species. It is believed that a person was infected by contact with an infected animal. The second type was associated with lymphadenopathy.

In this article, we will examine how AIDS proceeds, the consequences of the spread of its carrier over the human body.

The process of infection

The infection process is typical for all viruses. Inside the cell, the infectious agent builds its DNA into the chromosomal spiral of the host, thereby changing the nature of the expression of its genes, which results in an increase in the percentage of malignancies.

AIDS develops with the ingestion of an HIV infectious agent. It infects any cells on the surface of which there is a specific immunoglobulin receptor. During sexual contact with an infected partner, the virus dendritic cells and macrophages patrolling the epithelium of the genital organs, these receptors and T-lymphocytes (T-cells that detect and destroy foreign antigens), are present in the first place, many of which are present in the mucous membranes. If the virus enters the body with breast milk, then the input gates for it are M-cells of Peyer's plaques.

Finally, if the virus enters the bloodstream, it inevitably enters the lymph nodes where potential host cells that express T-lymphocytes are always present. Lymph nodes also contain antigen-presenting cells (which destroy antigens), which can transmit the AIDS virus. The consequences are always very serious.

Stages of the disease

In the first days after infection, the acute phase of the disease develops, when almost all immunoglobulin receptors of the cell become carriers of the intensely multiplying virus, most of which die. The infectious agent then goes into a latent state and is retained, mainly, as a provirus (embedded in the host cells), localizing primarily in T lymphocytes. They are formed after a meeting with a specific antigen and are activated if it appears again. They do not multiply and circulate in small amounts in the bloodstream.

Then there is an asymptomatic stage of the disease, during which the population of the virus becomes genetically heterogeneous as a result of the accumulation of mutations. The number of T cells is insignificantly reduced, as they die as the virus multiplies.

This is what AIDS is dangerous for. The consequences of the disease are that at the late stage of the syndrome the number of T cells is critically reduced, the multiplication of the virus in the tissues of the lymph nodes leads to the degeneration of the latter, and the virus itself becomes infected with a wide range of host cells. Cytotoxicity to participants of the cellular immune response, resistance to antiviral antibodies, in some cases tropism to different tissues, is activated.

During the development of the disease, any possible infection can be fatal for the body. Against the background of AIDS, people with a compromised immune system often develop other diseases of the viral etiology. For example, HIV was thought to be the cause of cancer for a long time, but later it turned out that against the background of the weakening of the immune status of the body, the cancer is caused by completely different pathogens, and this is not a consequence of HIV and AIDS.

Why is the human immune system unable to cope with HIV infection?

The fact is that the HIV virus turned out to be the most clever "manipulator", breaking the foundations of immunity and turning it to their own advantage. The "advantage" of HIV is the ability to persist for a long time in a latent form. If immediately after the initial infection the pathogenic process is suppressed, then gradually (within several years) the immune system is destroyed. The main target of the virus are T-lymphocytes. Normally, they trigger a series of immune response reactions, lose the ability to reproduce with the disease, and their total number falls. The remaining cells of the immune system (B-lymphocytes, monocytes and NK cells) cease to recognize the mediator signals of T cells, autoimmune reactions often begin. All antigen-presenting cells cease to function normally, as they are also infected with the virus.

Why do such consequences of AIDS occur?

Neutralizing antibodies against HIV are produced in the infected organism. However, their number is never high, and in a sense they even serve not as a defense, but as a stimulant for the variability of the virus. In parallel, a number of antibodies are synthesized that overlap the epitopes (part of the molecule recognized by the antibody) of the envelope of the virus, which are already inaccessible due to the special confirmation of their glycoproteins. Such antibodies are for some reason poorly recognized by the cells of the immune system.

In some cases, macrophages give the virus the ability to interact with additional receptors on the surface of target cells and penetrate them through endocytosis. Thus, the humoral immune response, the most powerful weapon of the immune system, when infected with HIV is completely disrupted.

Symptoms

Recognize the disease immediately difficult, because in the first stages of infection, there are no symptoms. And the following signs can easily be confused with other diseases. For example, enlarged lymph nodes, chronic fatigue and weakness, decreased appetite, weight loss, memory impairment, foggy consciousness - all these symptoms can also be caused by a nutritional deficiency. And this, as sometimes happens, the consequences of HIV infection and AIDS.

Therefore, the following symptoms should be specially noted: profuse sweating or chills, especially at night, the appearance of various stains or rashes on the skin, shortness of breath and rapid cough, fever, disruption of normal bowel function.

An important signal is the increased incidence of fungal infections. This applies to both genital and herpes viruses, oral cavity infections, etc. Therefore, when several of the symptoms appear simultaneously, it is important to undergo a check-up, not to mention annual medical check-ups, in order to diagnose AIDS in time. The consequences of the disease can manifest themselves at any time.

Statistics of the disease

Contrary to the efforts of doctors, scientists, the public, the support of the sick, the problem remains poorly controlled, and it is not yet possible to stabilize the situation. According to the World Health Organization, from the late 80's to 2006, more than 25 million people died from the "plague of the twentieth century." For many countries, this problem becomes more acute. According to the data announced at the international conference on AIDS, in 2010 more than 40 million people are considered infected carriers of the disease. The causes and consequences of AIDS are discussed above.

Data on the infected

The Russian Scientific and Methodological Center for Combating Immunodeficiency Syndrome cites the following data on infected people since 1994:

  • 1994 - 887 people;
  • 1999 - 30647 people;
  • 2004 - 296,045 people ,;
  • 2009 - 516,167 people.

Analyzing these data, we can trace the dynamics of the spread of the epidemic. Modern society still needs further studies of the sensitivity of the organism to a viral agent so that the effects of AIDS are not so terrible. On the body the virus acts, unambiguously, negatively.

Treatment and prevention

The noted abilities of HIV pose huge challenges in the search for ways to treat AIDS. Many measures to protect against viral infections are associated with the stimulation of the immune system, and this virus completely violates its coordinated action, which in this case can lead to unpredictable consequences.

It is impossible to fight HIV by destroying all cells infected by it, as this would lead to an irreparable loss of immune memory. This is the effect of AIDS. On the human body, it is necessary to have some other effect.

A promising direction in the development of AIDS therapy is the search for drugs that suppress the reproduction of the virus, primarily the process of reverse transcription, which as such is practically absent in eukaryotes. In this direction, certain progress has been made. So, if in the last trimester of pregnancy the mother takes Zidovudine or Lamivudine once, the child in 99% of cases is born not infected with HIV. The use of highly active antiretroviral therapy, when a patient is simultaneously treated with a reverse transcriptase inhibitor and a protease inhibitor, allows to slow down the development of the disease for many years.

Conclusion

Vaccination against AIDS is still unrealistic, since many aspects of the impact of HIV on the immune system have not been clarified. Not even the most immunogenic epitopes of viral proteins were detected. The rate of mutational variability of this virus, which has fallen into the human body, is very high, which excludes the possibility of developing long-term vaccines, while unsuccessful vaccination can stimulate the development of infection. These are terrible consequences for AIDS.

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