Background
Doxycycline post-exposure prophylaxis (DoxyPEP) use can significantly reduce the incidence of bacterial sexually transmitted infections (STIs), yet uptake has been low among people with HIV (PWH). In Washington, DC, high rates of STIs have been observed among PWH. We assessed STI diagnosis rates, DoxyPEP eligibility, use, and the potential impact of DoxyPEP prescribing on STI incidence among a large cohort of PWH in Washington, DC.
Methods
DC Cohort longitudinal HIV cohort participants were considered DoxyPEP eligible per the CDC guidelines if they were men who have sex with men (MSM) or transwomen (TW) diagnosed with gonorrhea, chlamydia, and/or syphilis in a calendar year during the observation period (1/1/2019-12/31/2023). We assessed the number of DoxyPEP eligible PWH and DoxyPEP prescriptions. We conducted descriptive statistics on demographics, sexual behaviors, and HIV viral loads (VL). We calculated STI diagnosis rates and estimated the potential impact of DoxyPEP prescribing by assessing the proportion of diagnoses potentially averted based on efficacy trial results. Using the number needed to treat (NNT) with DoxyPEP for one year to avert one STI diagnosis, we estimated the efficiency of three prescribing strategies for PWH with 1) any STI, 2) a concurrent STI, or 3) ≥2 STIs in the past 12 months.
Results
From 2019 to 2023, among 1,403 participants with ≥1 STI diagnosis, only 13 (0.93%) were prescribed DoxyPEP (85% male, median age 43, 85% MSM HIV risk factor, 92% had a rectal STI, and 46% had ≥2 STIs within a 12-month period). In any given year 50%-56% of STI cases were DoxyPEP eligible. Overall, there were 3,581 STI diagnoses, of which 2,890 were among MSM/TW (63.4 STI diagnoses/100 person-years). Among the 1,077 MSM or TW who had ≥1 bacterial STI diagnosis, 10% had a VL >200 copies/mL, 68% reported >1 sexual partner in the prior 3 months. Strategies with the lowest NNT were prescribing DoxyPEP for 12 months to PWH with a concurrent STI diagnosis (NNT=2.99 for any STI); with ≥2 STIs (NNT=3.22 for any STI); and to PWH with any STI (NNT=3.89 for concurrent STI diagnoses)(Figure).
Conclusions
Among a large clinical cohort of PWH, despite high STI rates, early uptake of DoxyPEP was minimal, yet a majority of PWH were DoxyPEP eligible. While the NNT varied based on the strategy, widespread DoxyPEP uptake could result in significant decreases in STI incidence among PWH. As DoxyPEP use rolls out, greater awareness of its use and prescribing efforts should be emphasized among PWH.
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