Prior PrEP use and discontinuation in individuals newly diagnosed with HIV

BACKGROUND: In settings with high uptake of HIV pre-exposure prophylaxis (PrEP), an increasing proportion of individuals newly diagnosed with HIV report prior PrEP exposure. Understanding patterns of PrEP use, discontinuation and adherence in such settings is essential to inform future HIV prevention strategies. METHODS: We conducted a retrospective case-note review of individuals newly diagnosed with HIV at 56 Dean Street, London, UK, between 1 January 2017 and 31 December 2024. Data collected included demographics, prior PrEP use, adherence and reasons for discontinuation and baseline blood results. Individuals with prior PrEP use were compared with those who had never used PrEP. RESULTS: Among 1080 individuals newly diagnosed with HIV, 210 (19.4%) reported prior PrEP use. The annual proportion with prior PrEP use increased from 4.3% in 2017 to 60.5% in 2024. Compared with never-PrEP users, those with prior PrEP use were more likely to have recently acquired HIV (85.7% vs. 58.2%, p < 0.00001), to have previously attended the clinic (70.0% vs. 37.7%, p < 0.00001) and to have undergone more frequent HIV testing. Among prior PrEP users, 36.2% reported PrEP discontinuation, and in those who had not discontinued PrEP at diagnosis, 73.5% reported poor adherence. The most common reasons for discontinuation were lack of PrEP supply, monogamy and gastrointestinal side effects. The only major resistance mutation that showed a significant difference between the two groups was M184I/V: 27 (19.6%) in PrEP-exposed versus 7 (0.8%) in not-PrEP-exposed. CONCLUSIONS: In this high-PrEP-uptake setting, a growing proportion of individuals newly diagnosed with HIV report prior PrEP use, most commonly characterized by discontinuation or suboptimal adherence. These findings highlight an ongoing unmet need for interventions that support PrEP persistence and continuity, including improved access pathways and alternative PrEP formulations.