What is HIV?

What is HIV?

The human immunodeficiency virus (HIV) infects cells of the immune system, destroying or impairing their function. Infection with the virus results in the progressive deterioration of the immune system, leading to "immune deficiency." The immune system is considered deficient when it can no longer fulfill its role of fighting infection and disease. Infections associated with severe immunodeficiency are known as "opportunistic infections," because they take advantage of a weakened immune system.

What is AIDS?

Acquired immunodeficiency syndrome (AIDS) is a surveillance term defined by the United States Centers for Disease Control and Prevention (CDC) and by the European Centre for the Epidemiological Monitoring of AIDS (EuroHIV). The term AIDS applies to the most advanced stages of HIV infection, defined by the occurrence of any of more than 20 opportunistic infections or HIV-related cancers.

How is HIV transmitted?

HIV can be transmitted through unprotected sexual intercourse (vaginal or anal), and oral sex with an infected person; transfusion of contaminated blood; and the sharing of contaminated needles, syringes or other sharp instruments. It may also be transmitted between a mother and her infant during pregnancy, childbirth and breastfeeding.

How quickly does a person infected with HIV develop AIDS?

The length of time can vary widely between individuals. Left untreated, the majority of people infected with HIV will develop signs of HIV-related illness within 5-10 years. However, the time between HIV infection and an AIDS diagnosis can be 10–15 years, sometimes longer. Antiretroviral therapy (ART) can slow the disease progression by decreasing an infected person’s viral load.