Which blood test is utilized to confirm an HIV infection?

The enzyme-linked immunosorbent assay (ELISA) is the blood test used to confirm an HIV infection. This test works by detecting antibodies to HIV in the blood, indicating whether a person has been infected with the virus. If the ELISA test is positive, it is often followed by a confirmatory test, such as the Western blot or an HIV nucleic acid test, to ensure the accuracy of the diagnosis.

The other tests listed serve different purposes and are not designed for detecting HIV. A thyroid function test assesses hormone levels related to thyroid health, hemoglobin A1C measures blood sugar control over time, and a complete metabolic panel evaluates various metabolic functions, including kidney and liver performance. None of these tests provide information about HIV infection status, making the ELISA specifically vital for this purpose.