An HIV carrier is someone who has HIV but does not have symptoms of the disease. Because HIV infection is frequently without symptoms, routine screening is important.

Basically the test is to check for the HIV antibody and NOT the HIV virus itself.

HIV screening for blood products is not 100 percent effective because someone can be recently infected and contagious, but have a negative test. That's why screening for high-risk behaviors is also used to protect the blood supply.

The most common screening for HIV tests for antibodies in the blood; however most infants born to infected mothers test positive for 6-18 months because of the presence of maternal antibodies.

You can be treated to the point where the viral load is undetectable, but the antibodies will always remain and the HIV screening test will remain positive.