What confirms an HIV infection after a positive ELISA test?

A positive ELISA test indicates the initial presence of antibodies to HIV, but it is not definitive on its own due to the possibility of false positives. The Western Blot test serves as a confirmatory test that detects specific proteins produced by the HIV virus. This test looks for the presence of these antibodies to particular HIV proteins, which are distinct and more specific than those identified in the ELISA. By confirming the presence of these specific antibodies, the Western Blot test provides a definitive diagnosis of HIV infection.

In contrast, the other options do not confirm HIV infection. The Comprehensive Metabolic Panel assesses various metabolic parameters but does not detect HIV. The CD4 count is a measure of immune function and provides insight into the progression of HIV infection rather than a diagnosis of it. The Liver Function Test evaluates liver health, which can be affected by various factors, including HIV, but is not a diagnostic tool for confirming the presence of the virus itself. Thus, the Western Blot test is the gold standard for confirming an HIV diagnosis after an initial positive ELISA.