Children, adolescents and adults are all screened for HIV infection in the same way: using a test called ELISA that allows the presence of the HIV antibody in the blood to be detected. Antibodies are the specific proteins that the body produces in order to fight infections; the antibodies specific to HIV are produced in response to infection with this virus. People who have antibodies to HIV in their blood are HIV-positive (or seropositive). If the ELISA test is positive, the patient’s HIV-positive status will be confirmed by another test, called Western Blot, in order to determine whether HIV is actually present. If this test also comes back positive, the patient is definitely infected with HIV.