A person with AIDS has a very weak immune system, turning normally mild or rare diseases into potentially fatal conditions.
Blood tests are most common, but new saliva tests are increasingly available.
A person can be HIV-infected for many years while looking and feeling healthy, with no signs at all of being sick. Age makes no difference. Sex without a latex condom. HIV is found in semen, vaginal fluids and blood. HIV can enter the body through any type of sexual intercourse, including vaginal, anal and oral sex.