HIV PEP Timing — MFDS Part 1 MCQ

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ModerateMicrobiologyHIV PEP TimingMFDS Part 1

A dentist sustains a significant percutaneous needlestick injury involving blood from a patient known to have HIV with a detectable viral load. Following urgent risk assessment, HIV post-exposure prophylaxis is indicated. Within what time should PEP ideally be initiated?

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Correct answer: C — 24 hours

The correct answer is C. When HIV PEP is indicated after a significant needlestick injury, it should be started as soon as possible, ideally within 24 hours. Treatment should not be delayed while awaiting specialist review or test results that are not immediately available. The 72-hour interval in option A is the maximum recommended initiation window, not the ideal target; PEP is generally not initiated after this point because efficacy is expected to decline substantially. One week, two weeks and one month are therefore too late. Immediate wound care, incident reporting and urgent assessment by occupational health, emergency medicine or an HIV specialist are also required.

Reference: Worcestershire Acute Hospitals NHS Trust, Guidelines for the use of post exposure prophylaxis (PEP) following sexual, occupational or non-occupational exposure to HIV, section 4, approved March 2025. https://apps.worcsacute.nhs.uk/KeyDocumentPortal/Home/DownloadFile/1511