Infection Control · single question
After a needlestick injury with a potentially HIV-positive needle, when should post-exposure prophylaxis (PEP) ideally be started?
Show answer and explanation
Correct answer: C. Within 24 hours
PEP for HIV should ideally be started as soon as possible — ideally within 24 hours of exposure. The absolute maximum window is 72 hours; after that PEP is not effective. Hopkins guidelines specify within 2 hours as the ideal target but 72 hours as the hard cutoff. The key message: start ASAP, do not delay.
- A. ❌ PEP started after 72 hours is not considered effective.
- B. ❌ 72 hours is the absolute maximum cutoff — not the ideal start time.
- C. ✅ CORRECT – PEP should ideally begin within 24 hours of HIV exposure. The absolute cutoff is 72 hours.
- D. ❌ While starting within 1 hour is ideal in some protocols, '1 hour' is not the standard answer on INBDE — 24 hours is the more commonly tested threshold.
Note: ⚠️ FLAG: Source says '0-24h.' Verified: ideally within 24h, absolutely no later than 72h. Both 24h and 72h appear in questions — the 'ideal' is within 24h (some protocols say 2h), the 'maximum' is 72h.
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