The human immunodeficiency virus (HIV) is a retrovirus that infects cells of the immune system, destroying or impairing their function. As the infection progresses, the immune system becomes weaker, and the person becomes more susceptible to infections. The most advanced stage of HIV infection is acquired immunodeficiency syndrome (AIDS). It can take 10-15 years for an HIV-infected person to develop AIDS; antiretroviral drugs can slow down the process even further.
HIV is transmitted through unprotected sexual intercourse (anal or vaginal), transfusion of contaminated blood, sharing of contaminated needles, and between a mother and her infant during pregnancy, childbirth and breastfeeding.
WHO programmes and activities
HIV/AIDS in WHO regions
- Treatment 2.0
- Universal access to HIV/AIDS prevention, treatment and care
- Global health sector strategy on HIV/AIDS 2011-2015
WHO's support to implement the Global Health Sector Strategy on HIV/AIDS
- Antiretroviral treatment as prevention (TASP) of HIV and TB
- WHO guidelines on HIV/AIDS