AIDS is caused by infection with a virus called human immunodeficiency virus
(HIV). This virus is passed from one person to another through blood-to-blood
and sexual contact. In addition, infected pregnant women can pass HIV
to their babies during pregnancy or delivery, as well as through breast
feeding. People with HIV have what is called HIV infection. Some of
these people will develop AIDS as a result of their HIV infection.
For more information see “What is HIV?”