HIV transmission through body fluids means that the body fluids of a person with HIV come into contact with a healthy person, causing the healthy person to become infected with HIV. Body fluids such as semen, prostate fluid, vaginal secretions, breast milk, cerebrospinal fluid, ascites, and blood plasma contain high viral loads and can cause infection. Saliva as well as urine contain very small amounts of the virus but not enough to cause infection. The most common way to cause transmission of bodily fluids is through unprotected sex. When you have sex with someone who has AIDS, your genitals can exchange bodily fluids during friction, which can cause infection in a healthy person, or through contact with the bodily fluids of someone who has AIDS.