Follow-Up Testing Schedule for Cabotegravir PrEP
The correct answer is C: One month later for HIV-1 RNA testing and 4 months later for STI testing is NOT accurate based on current guidelines. The correct approach is HIV testing at every injection visit (every 8 weeks after the initial 4-week interval) using rapid point-of-care antibody testing, NOT routine HIV-1 RNA testing, and STI testing every 4 months.
HIV Testing Protocol for Cabotegravir PrEP
HIV-1 RNA testing is NOT recommended as part of routine monitoring for cabotegravir PrEP because it has low positive predictive value and false-positive results carry significant negative consequences 1. This is a critical distinction that makes options A, C, and D incorrect.
The appropriate HIV testing schedule includes:
Rapid point-of-care HIV antibody testing on the day of each injection (every 8 weeks after the initial 4-week interval between the first two injections) prior to administering cabotegravir 1
Laboratory-based antigen/antibody testing should be sent simultaneously with the rapid test, but injections should not be delayed pending these results 1
The FDA label emphasizes that patients must get tested for HIV-1 "when your healthcare provider tells you" and reinforces the importance of maintaining HIV-negative status throughout PrEP use 2
STI Testing Schedule
STI testing should be performed every 4 months, which corresponds to every second injection visit 1. This testing includes:
- Genital and non-genital gonorrhea and chlamydia testing by nucleic acid amplification test (NAAT) 1
- Syphilis testing 1
Important Clinical Caveats
If HIV acquisition is suspected during cabotegravir PrEP use, two sequential testing results showing HIV RNA detection at any level is highly predictive of true HIV infection 1. This is when RNA testing becomes clinically valuable—not for routine monitoring, but for diagnostic confirmation when infection is suspected.
Delayed HIV detection is a known concern with cabotegravir PrEP due to viral suppression and reduced/delayed antibody production 3, 4. Patients should be counseled to report any flu-like symptoms (tiredness, joint/muscle aches, sore throat, rash, enlarged lymph nodes, fever, headache, vomiting, diarrhea, or night sweats) immediately, as these may indicate acute HIV infection 2.
INSTI resistance has been documented in breakthrough infections among those using cabotegravir PrEP, making accurate and timely HIV detection critical 4, 5.
Why None of the Provided Options Are Fully Correct
None of the multiple-choice options accurately reflect guideline-based care:
- Options A and C incorrectly suggest routine HIV-1 RNA testing at 1 month
- Options B and D incorrectly suggest routine HIV-1 RNA testing at 3 months
- The correct HIV testing approach uses rapid antibody testing at each injection visit (every 8 weeks), not scheduled RNA testing at fixed intervals 1
- Only the STI testing interval of 4 months (option C) aligns with guidelines 1