HIV Testing Frequency for Individuals on PrEP
Individuals on HIV Pre-Exposure Prophylaxis (PrEP) must undergo HIV testing quarterly (every 3 months) using a combined HIV antibody and antigen test. 1
Testing Schedule During PrEP Use
Initial Month
- Perform a combined HIV antibody and antigen test at the 1-month visit after PrEP initiation 1
Quarterly Testing (Every 3 Months)
- Combined HIV antibody and antigen testing is mandatory at every quarterly visit 1, 2
- PrEP prescriptions should not exceed 90 days without interval HIV testing 2, 3
- This quarterly HIV testing requirement has the highest evidence rating (AIa) from the International Antiviral Society-USA Panel 1
Additional Quarterly Testing
Beyond HIV testing, the following should also be performed quarterly:
- STI screening (gonorrhea and chlamydia by nucleic acid amplification test at genital and non-genital sites) 1, 2
- Syphilis testing 1, 2
- Pregnancy testing for individuals of childbearing potential 1, 2
Critical Monitoring Caveats
Missed PrEP Doses
- If PrEP has been discontinued for 7 or more consecutive days, repeat combined HIV antibody and antigen testing before restarting PrEP 1, 2, 3
Injectable PrEP (Cabotegravir)
- Rapid point-of-care HIV testing should be performed on the day of each injection prior to administration 1
- Injections are given every 8 weeks after an initial 4-week interval 1, 3
Rationale for Quarterly Testing
The quarterly testing interval is critical because:
- PrEP can delay HIV detection by suppressing viral load and delaying seroconversion by approximately 7 days 4
- Starting PrEP during undiagnosed acute HIV infection can lead to drug resistance 5
- Even with daily PrEP use, most early HIV infections remain detectable by combined antibody/antigen testing within 4 weeks of exposure 4
- The 3-month interval ensures timely detection while balancing practical clinical visit frequency 1
Flexibility in Stable Patients
- For stable patients with good adherence and on-time refills, telemedicine visits may substitute for in-person visits, provided laboratory testing can be completed remotely 1, 3
- During circumstances where standard quarterly follow-up is infeasible (such as during the COVID-19 pandemic), extending PrEP medication provision up to 6 months may be reasonable for carefully selected patients with demonstrated adherence and clinical stability, though this should be individualized 1
The quarterly HIV testing requirement is non-negotiable for safe PrEP management and represents the standard of care across all major guidelines. 1, 2