Does a person exposed to a female of unknown Human Immunodeficiency Virus (HIV) status, presenting to the clinic more than 72 hours after exposure, need Pre-Exposure Prophylaxis (PrEP)?

Management of HIV Exposure Beyond 72 Hours

For a person exposed to a female of unknown HIV status who presents to the clinic more than 72 hours after exposure, Post-Exposure Prophylaxis (PEP) is not routinely recommended, but Pre-Exposure Prophylaxis (PrEP) should be considered if there is ongoing risk of HIV exposure. 1

Assessment of Late Presentation (>72 hours)

• Current CDC guidelines (2025) clearly state that nPEP (non-occupational Post-Exposure Prophylaxis) is not routinely recommended when presentation occurs more than 72 hours after exposure 1
• The effectiveness of PEP significantly decreases when initiated beyond the 72-hour window, making the risk-benefit ratio unfavorable 2
• For exposures to a source of unknown HIV status, a case-by-case determination is recommended, but this still applies primarily within the 72-hour window 1

Risk Assessment Considerations

• The type of sexual exposure affects transmission risk (higher for anal intercourse, lower for vaginal intercourse) 3
• Female partners of unknown HIV status represent an indeterminate risk that requires evaluation of local HIV prevalence and specific exposure characteristics 1
• Consider factors that might increase risk, such as whether the source belongs to a high-prevalence group (e.g., injection drug users, commercial sex workers) 3

Recommended Approach for This Patient

1. Perform baseline HIV testing of the exposed person immediately using a rapid test if available 2
2. Attempt to determine HIV status of the source if possible and they consent to testing 1
3. Do not initiate PEP as presentation is beyond the 72-hour window when PEP is considered effective 1
4. Evaluate for PrEP initiation if the patient has ongoing risk of HIV exposure 1

PrEP Consideration for Ongoing Risk

• If the patient has ongoing risk factors for HIV acquisition, initiation of PrEP should be strongly considered 1, 4
• PrEP is an effective HIV prevention method for individuals at increased risk, including women 4, 5
• The recommended PrEP regimen is typically a fixed-dose combination of tenofovir disoproxil fumarate and emtricitabine administered as a single daily dose 4
• PrEP requires ongoing monitoring every 3 months, including HIV testing, STI screening, and renal function assessment 4

Common Pitfalls to Avoid

• Delaying HIV testing of the exposed person while considering interventions 2
• Using PEP for recurrent high-risk behaviors instead of transitioning to PrEP 3
• Failing to provide comprehensive sexual health counseling and risk reduction strategies 3
• Not considering other sexually transmitted infections that may require testing and treatment 2

Follow-up Care

• Schedule HIV testing at 4-6 weeks and 12 weeks after exposure 2
• Provide risk-reduction counseling to prevent future exposures 3
• If PrEP is initiated, ensure regular follow-up visits every 3 months for HIV testing and monitoring 4
• Consider hepatitis B vaccination status and need for prophylaxis 3