Post-exposure prophylaxis (PEP) should be given as soon as possible to healthcare personnel (HCP) after parenteral exposure to the human immunodeficiency virus (HIV). Regardless of whether PEP is administered, HIV-antibody testing should be performed at what times, post-exposure?

• A. Immediately, then at both six weeks and four months post-exposure
• B. Immediately, and at six weeks and three months post-exposure
• C. Only at six weeks post-exposure
• D. Only at four months post-exposure

Answer: (A)

Testing after an HIV exposure is designed to catch seroconversion during the window period while establishing what the person’s status was at baseline. The most important first step is to perform an HIV test immediately to determine if the person was already infected before the exposure. Because antibodies may take time to develop, follow-up testing at later points is needed to detect any infection that did occur as a result of the exposure. Scheduling tests at six weeks and around four months after exposure covers the early and later parts of the window period, increasing the chance of identifying seroconversion even if PEP was used. This approach is applied regardless of whether PEP was given because PEP reduces, but does not guarantee, that infection will not take hold, and individual variation can affect when antibodies become detectable.