How do people get aids?

Bodily fluids. Aids (acquired immune deficiency syndrome) is caused by infection with the human immunodeficiency virus. Hiv is spread in bodily fluids, including semen, vaginal secretions, blood, and breast milk. People usually get aids by having unprotected sex with an infected partner, sharing needles with an infected person, or breastfeeding from an infected mother.
By getting infected. Or having contact with a body fluid from another person who has the HIV virus in their system. Blood contact, semen, vaginal fluid and breastmilk are all known to transmit the virus. Saliva doesn't appear to be much of a risk for tranmission.