HIV is human immunodeficiency virus which causes AIDS. It infects and damages part of body’s defenses against infection, which are called white blood cells. These white blood cells are also known as lymphocytes which fight against germs.
The transmission of HIV takes place through direct contact with someone’s body fluid infected with virus or with blood. Coming into contact can occur mainly with sharing of needles or with unprotected sex with an infected person.
HIV enters commonly through sexual intercourse through vulva, rectum, penis, vagina linings, and rarely through mouth. The transmission increases with sexually transmitted diseases.
How HIV progresses to AIDS?
HIV is described as a gradual decline of immune functioning. When HIV infection occurs, CD4+ T cells, which are crucial immune cells are disabled and killed. These cells are called T-helper cells. They play an important role in immune response and perform special function like signaling other cells in the immune system.
800 to 1200 CD4+ T cells per cubic millimeter of blood is usual count in healthy and uninfected person. The cell count in the blood slowly decreases when a person is affected with HIV. When the person’s cell count falls below 200 per cubic millimeter, the person is exposed to infections and cancers that characterize AIDS, which is the HIV’s end stage.
If the person is affected with AIDS, his lungs, intestinal tract, eyes, brain, and other organs are affected. The person is susceptible to weight loss, diarrhea, neurologic conditions and cancers.
According to most scientists, AIDS is caused by HIV, as HIV kills CD4+ T cells and interferes with normal function. HIV virus also triggers other events that weaken a person’s immune system. Most people infected with HIV carry virus for years before damage is done to immune system for AIDS to develop.
Some tests have shown connection between amount of HIV in the blood and decrease in CD4+ T cells and the development of AIDS. When antiretroviral therapies are used, the amount of virus in the body is reduced, which can slow the destruction of person’s immune system.
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