AIDS: Encyclopedia II - AIDS - Infection by HIV

AIDS - Infection by HIV

AIDS is the most severe manifestation of infection with HIV. HIV is a retrovirus that primarily infects vital components of the human immune system such as CD4+ T cells, macrophages and dendritic cells. It also directly and indirectly destroys CD4+ T cells. As CD4+ T cells are required for the proper functioning of the immune system, when enough CD4+ cells have been destroyed by HIV, the immune system barely works, leading to AIDS. Acute HIV infection progresses over time to clinical latent HIV infection and then to early symptomatic HIV infection and later, to AIDS, which is identified on the basis of the amount of CD4 positive cells in the blood and the presence of certain infections.

In the absence of antiretroviral therapy, progression from HIV infection to AIDS occurs at a median of between nine to ten years and the median survival time after developing AIDS is only 9.2 months ^[7]. However, the rate of clinical disease progression varies widely between individuals, from two weeks up to 20 years. Many factors affect the rate of progression. These include factors that influence the body's ability to defend against HIV, including the infected person's genetic inheritance, general immune function ^[8][9][10], access to health care, age and other coexisting infections ^[11][12][13]. Different strains of HIV ^[14][15] may also cause different rates of clinical disease progression.

Adapted from the Wikipedia article "Infection by HIV", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki