what test is used to confirm a diagnosis of hiv?

To confirm a diagnosis of HIV, there are three types of tests used: antibody tests, antigen/antibody tests, and nucleic acid tests (NAT) . Antibody tests look for antibodies to HIV in a persons blood or oral fluid, and can take 23 to 90 days to detect HIV after exposure. Antigen/antibody tests look for both HIV antibodies and antigens, and are recommended for testing done in labs. NATs look for the actual virus in the blood, and can usually detect HIV 10 to 33 days after exposure. An initial HIV test usually will either be an antigen/antibody test or an antibody test. If the initial HIV test is positive, the person should go to a healthcare provider to get follow-up testing. Although HIV tests are generally accurate, no test can detect the virus immediately after infection.