Despite comprehensive information about HIV transmission routes and prevention methods, unfortunately, the HIV epidemic is not reduced. To understand the principles of HIV prevention is easy. This virus does not live outside the body fluids of a person not transmitted through casual contact, and each person has the opportunity to protect themselves from HIV and to help their loved ones.
Thus, HIV - human immunodeficiency virus. When injected into the human body, HIV destroys the immune system, which protects us from disease and infection. The human immunodeficiency virus belongs to the family of retroviruses (Retroviridae), the genus of lentiviruses (Lentivirus). Name Lentivirus comes from the Latin word lente - slow. This name reflects one of the characteristics of the viruses of this group, namely the slow and uneven rate of development of infectious process in the host. Lentiviruses are characterized by a long incubation period.
The virus is found in all bodily fluids and tissues of the body. According to the degree of concentration of the virus in the body: blood, lymph, semen, vaginal secretions. In the rest of the body fluids of the contents of the virus is not sufficient for infection (saliva, tears, sweat, urine, feces, and other).
The human immunodeficiency virus was discovered in 1983 in the study of the etiology of AIDS. The first official scientific reports of AIDS were two articles about unusual cases, the development of Pneumocystis pneumonia and Kaposi's sarcoma in homosexual men, published in 1981. In July 1982 for the first time to denote a new disease, the term AIDS was proposed. In September of the same year on the basis of a number of opportunistic infections diagnosed in homosexual men, drug users, patients with hemophilia A, AIDS was first given full definition as a disease. Several works were published in the period from 1981 to 1984, linking the risk of AIDS from anal sex or the influence of drugs. Simultaneously been working on a hypothesis about the possible infectious nature of AIDS. In 1983, HIV was independently discovered in two laboratories: the Institute Pasteur in France under the direction of Luc Montagnier and at the National cancer Institute in the United States under the leadership of Robert Gallo.
According to research published may 20, 1983 was the first to allocate a new retrovirus. Researchers have assumed that their viruses can cause AIDS.
In 1986 it was discovered that the virus, discovered in 1983 by French and American researchers were genetically identical. Original title of the viruses were abolished and was proposed one common name - HIV.
In 2008, Luc Montagnier and Francoise Barre-Sinoussi were awarded by the Nobel prize in physiology and medicine «for their discovery of human immunodeficiency virus».
HIV infects primarily cells of the immune system (CD4+ T-lymphocytes, macrophages and dendritic cells), as well as some other types of cells. Extending into the cells of the specified types, the virus begins to multiply. This, ultimately, leads to the destruction and death of the infected cells. The presence of HIV over time causes a disturbance of the immune system due to selective destruction of them immunocompetent cells and suppress their subpopulations. Released viruses are introduced into the new, and the cycle repeats. Gradually the number of CD4+ lymphocytes is reduced so that the body can no longer withstand the causative agents of opportunistic infections, which are not dangerous or not dangerous for healthy people with normally functioning immune system.

AIDS - acquired immune deficiency syndrome, last, end-stage disease, the result of the destruction of a significant part of the human immune system. HIV can weaken the immune system to a specific state, when the body starts to develop so-called opportunistic diseases. The diagnosis AIDS is usually made some years later after HIV infection, when at the person one or several very serious diseases to which leads the progressing weakening of immune system owing to corrupting of CD4+ of lymphocytes develop. The current antiretroviral therapy reduces the activity of the virus and reduce the harm it causes to the immune system, preventing, thus, the development and transition of HIV into AIDS.