HIV is primarily found in the blood, semen, or vaginal fluid of someone who is infected with the virus and is transmitted in four ways:
- Having unprotected sex (anal, oral or vaginal) with someone infected with HIV
- Sharing needles and syringes with someone infected with HIV
- Being exposed to the virus as a fetus or infant before or during birth or through breastfeeding from an HIV-infected mother
- Receiving a transfusion of HIV-infected blood or blood products. In the United States, all donated blood and blood products have been screened for HIV since 1985