by World Wise Schools
More than 33 million people in the world - including more than 1 million people in the U.S. - are living with HIV, the virus that causes AIDS.
Once a person becomes infected through sexual transmission, sharing needles with an HIV positive person, or being born to an HIV positive mother, he or she is infected for life. A person develops AIDS when the amount of HIV virus in the blood becomes too high and the amount of infection-fighting white blood cells becomes too low.
When a person has AIDS, their immune system may become unable to fight off infections like pneumonia. Being unable to recover from these infections is often the cause of death for people with AIDS. There is no cure or vaccine for HIV. Some types of medications, known as antiretroviral drugs (ARVs), can help slow the destruction of the immune system.
Health organizations and governments around the world have been working since the early 1980's to halt and reverse the spread of the disease.