HIV/AIDS Glossary

Human Immunodeficiency Virus (HIV)

The virus that causes AIDS, which is the most advanced stage of HIV infection. HIV is a retrovirus that occurs as two types: HIV-1 and HIV-2. Both types are transmitted through direct contact with HIV-infected body fluids, such as blood, semen, and vaginal fluids, or from a mother who has HIV to her child during pregnancy, labor and delivery, or breastfeeding (through breast milk).

Related Term(s): Acquired Immunodeficiency Syndrome, HIV-1, HIV-2, Retrovirus


(Click to enlarge)
HIV virion labeled with components of virus.

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