The AIDS agent is a Lentivirus, HIV (HIV-1 and HIV-2) for human immunodeficiency virus. It infects immune system cells, T4 lymphocytes which carry the appropriate receptor (CD4 protein), but can also infect other cell types.
The virus is transmitted through specific body fluids in which viral particles are found. It may be transmitted sexually (by genital secretions), through blood (by transfusion or needle-sharing) or from mother to fetus (by blood-placental spread, during childbirth or whenbreast-feeding).
According to the WHO and Onusida estimates, there were 33.4 million people living with HIV at the end of 2008.
It is not yet possible to cure AIDS, as the viral genome incorporates itself into the cell and therefore remains latent and invisible to the immune system. It is therefore important to protect against infection, for example by using a condom.
Nevertheless, there are treatments to slow the progression of the disease towards the AIDS stage. These involve antivirals, which are not sufficiently effective on their own but are more effective when they are taken in combination. When three are given, the term triple-therapy is used.
To find out more about AIDS, go to our specific page.
Use of a condom protects against HIV infection. © DR