Final answer:
In infants, HIV detection is confirmed by specific tests such as Western blot or PCR, following initial screening with an ELISA test to overcome issues of cross-reactivity and the presence of maternal antibodies.
Step-by-step explanation:
The detection of HIV in infants is confirmed by a laboratory performing tests such as Western blot or PCR (Polymerase Chain Reaction). While antibody-based serological tests like the indirect ELISA (Enzyme-Linked Immunosorbent Assay) are commonly used for initial screening, they can produce false positives due to cross-reactivity with antibodies against other antigens. Therefore, a suspected positive result on an initial ELISA test is typically confirmed with a more specific immunoblot, which identifies HIV peptides, or a nucleic acid test like RT-PCR that detects the presence of viral RNA. It is especially important to use these confirmatory tests for infants, as maternal antibodies can interfere with the accuracy of antibody-based tests.