Should a patient on emtricitabine (Emtriva)/tenofovir disoproxil fumarate (TDF) (Truvada) for pre-exposure prophylaxis (PrEP) stop treatment if in a monogamous relationship with a virologically suppressed HIV partner?

Recommendation for Discontinuing PrEP with Virologically Suppressed Partner

You can counsel this patient that he may safely discontinue F/TDF PrEP given his partner's documented virologic suppression for two years, as the risk of HIV transmission from a consistently suppressed partner is effectively zero (U=U: Undetectable = Untransmittable). 1

Evidence Supporting U=U (Undetectable = Untransmittable)

The most recent IAS-USA guidelines (2018) explicitly state that PrEP is recommended for "HIV-seronegative partners of HIV-infected persons who are not consistently virally suppressed." 1 This directly implies that PrEP is not necessary when the partner maintains consistent viral suppression.

• The 2016 IAS-USA guidelines similarly recommend PrEP for "HIV-seronegative partners of HIV-infected persons who do not have viral suppression," reinforcing that viral suppression eliminates the need for PrEP. 1

• The guidelines note that maintaining U=U status requires continued viral suppression, and 3 to 6 months of documented suppression may be required before transmission risk is eliminated. 1 This patient's partner has been suppressed for two years, well exceeding this threshold.

Critical Counseling Points

Ongoing Monitoring Requirements

• The HIV-positive partner must maintain durable viral suppression through continued adherence to antiretroviral therapy and regular viral load monitoring. 1
• A single viral load measurement is insufficient; durable suppression requires consistent documentation over time. 1

Risk of Outside Partners

• Transmission can still occur if the HIV-seronegative partner has sexual partners outside the monogamous relationship. 1 This is a critical caveat that must be discussed explicitly.
• If the patient anticipates any sexual activity outside this relationship, continuing PrEP would be appropriate. 1

STI Prevention

• PrEP does not prevent other sexually transmitted infections, and neither does having a virologically suppressed partner. 1
• Condoms remain essential for STI prevention if there are concerns about other infections. 1

Hepatitis B Considerations

• If this patient has active hepatitis B infection (HBsAg positive), discontinuation of F/TDF could lead to acute HBV flares or hepatic decompensation, particularly with cirrhosis. 1, 2
• HBsAg testing should be reviewed before discontinuation, with careful monitoring of liver function after stopping if HBV is present. 1, 2

Why Other Options Are Incorrect

Option A (continuing PrEP) contradicts guideline recommendations that specifically limit PrEP to partners of individuals who are not consistently virologically suppressed. 1

Option B (switching to TAF/FTC) is inappropriate because:

• TAF/FTC is not recommended for PrEP at this time per IAS-USA guidelines. 1
• There is no evidence that TAF/FTC has superior efficacy to TDF/FTC for HIV prevention. 3
• The fundamental issue is whether PrEP is needed at all, not which formulation to use.

Option D (stopping with condom use) is unnecessarily restrictive given the evidence for U=U, though condoms remain important for STI prevention rather than HIV prevention in this context. 1

Post-Discontinuation Considerations

• If the patient discontinues PrEP, continue F/TDF for 1 week after the last sexual exposure to ensure adequate protection during the washout period. 1

• The patient should be counseled to restart PrEP immediately if the partner's viral suppression is lost or if sexual activity occurs outside the monogamous relationship. 1

• Regular communication about the partner's viral load status is essential to maintain this prevention strategy. 1