Family Nurse Practitioner Exam

Which of the following is the confirmatory test for the HIV screening test?

1. ELISA test for HIV

2. Western blot

3. HIV polymerase chain reaction test

4. HIV antibody

The correct answer is: Western blot

The confirmatory test for an HIV screening test is the Western blot. This test is typically performed after an initial screening test, such as the ELISA, yields a reactive or positive result. The Western blot is considered a more specific test and helps to confirm the presence of HIV antibodies in the blood. The Western blot functions by detecting different proteins associated with the HIV virus, which provides a more reliable confirmation of the infection. While the ELISA test serves as an effective screening method due to its high sensitivity, it is possible for it to yield false-positive results, prompting the need for a confirmatory test like the Western blot. Other tests listed, such as the polymerase chain reaction (PCR) test, are used primarily for different purposes, such as measuring the viral load in individuals diagnosed with HIV or confirming acute infection. However, they are not the standard confirmatory tests for initial screening results. Similarly, HIV antibody tests are also part of the screening process rather than a confirmatory test. Thus, the Western blot is the preferred and established confirmatory method following a reactive screening test for HIV.