Standard blood tests for HIV detect the infection in the blood from 2 to 8 weeks following infection. However, it can take up to 6 months for the virus to show up in the blood. The newest blood tests screen for the HIV antigen, which is a protein that can be detected in the blood up to 20 days sooner than standard blood tests. Urine or saliva can also be used to test for the antibodies to the HIV virus, which indicates its presence in the body.
WebMD recommends testing for anyone who has had multiple sexual partners or unprotected sex with a partner who might be positive for HIV. Those who have injected steroids or drugs or who have used a shared needle to use drugs should also be tested. Anyone with hepatitis, tuberculosis, herpes or sexually transmitted diseases should be tested, as should anyone who had sex for money or drugs. Having sex with anyone who has a history of any of these behaviors also puts a person at risk for HIV and necessitates testing.Learn more about Conditions & Diseases