After an HIV infection, it takes your body 23 to 90 days to produce enough antibodies and antigens to be detected by a standard blood test after an exposure.2 For individuals on PrEP, this detection period can extend to an average of 126 days, and up to 600 days, for a serology test to show a positive result.3
Due to this delay, the CDC now mandates that, as of December 2021, an HIV PCR test must be performed alongside a serology test at every PrEP visit.1 PCR tests can detect a breakthrough HIV infection much sooner than serology tests.2 According to a recent study, unfortunately, the implementation of CDC PrEP guidelines across the nation varies significantly, thereby restricting our patients' access to the necessary care.4
If a breakthrough infection occurs, it's crucial to discontinue PrEP and start HIV therapy immediately to prevent treatment resistance and ensure the best long-term outcomes.5 Delayed detection and treatment can lead to resistance to first-line HIV therapies, resulting in significantly worse outcomes for patients.1, 6
References
Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2021 Update Clinical Practice Guideline. Accessed Aug 26, 2024 ; REF-35585
https://www.hiv.gov/hiv-basics/hiv-testing/learn-about-hiv-testing/hiv-testing-overview Accessed Aug 26, 2024 ; REF-43717
Analysis of False-negative RAPID Tests Performed on Oral Fluid in 3 International Clinical Research Studies. 2017. CID 64(12): 1663-9. Accessed Aug 26, 2024 ; REF-09609
High Rates of Missed HIV Testing Among Oral PrEP Users in the United States From 2018-2021: A National Assessment on Compliance With HIV Testing Recommendations of the CDC PrEP Guidelines. Open Forum Infect Dis. 2024 May 23;11(5):ofae254. doi: 10.1093/ofid/ofae254. PMID: 38798900; Accessed Aug 26, 2024 ; REF-43721
Breakthrough Acute HIV Infections among Pre-Exposure Prophylaxis Users with High Adherence: A Narrative Review. Viruses. 2024 Jun 12;16(6):951. doi: 10.3390/v16060951. PMID: 38932243 ; Accessed Aug 26, 2024 ; REF-43718
From Innovation to Implementation: The Evolution of HIV Pre-Exposure Prophylaxis and Future Implications. Pathogens. 2023 Jul 9;12(7):924. doi: 10.3390/pathogens12070924. PMID: 37513771; Accessed Aug 26, 2024 ; REF-41893