How should I interpret a reactive HIV test result, and what are the next steps for confirmation?

A reactive HIV test result indicates that HIV antibodies and/or antigens have been detected, suggesting possible HIV infection. However, a reactive result is not diagnostic on its own and requires confirmatory testing to establish a definitive diagnosis ³,¹.

Interpretation: A reactive result from an initial screening test, such as a fourth-generation serological test that detects both HIV antibodies and p24 antigen, has high sensitivity but can yield false positives, especially in low prevalence settings. Therefore, all reactive results must be confirmed by more specific serological tests, typically performed in specialist laboratories ³,¹.

Next steps for confirmatory testing: Following a reactive screening test, the patient should be referred urgently to a specialist HIV clinic for confirmatory serological testing, ideally to be seen within 48 hours and no later than 2 weeks after the initial reactive result ¹,²,³. Confirmatory tests usually include a combination of antibody differentiation assays and nucleic acid tests (NAT) such as polymerase chain reaction (PCR) to detect viral RNA, which help confirm infection and exclude false positives (Mylonakis et al., 2000).

During this period, it is important to provide the patient with information about the testing process, sources of support, and risk reduction strategies to protect contacts, including safer sexual practices and harm reduction advice for injecting drug use ¹,².

Healthcare professionals should ensure clear referral pathways are in place for confirmatory testing and subsequent specialist care, including prompt initiation of antiretroviral therapy if confirmed positive ¹,³.