CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

1152 Early Adopters: Implementation of Doxycycline Postexposure Prophylaxis in a Boston Health Center Kenneth H Mayer 1 , Michael Traeger 2 , Sy Gitin 1 , Jessica Kraft 1 , Taimur Khan 1 1 Fenway Health, Boston, MA, USA, 2 Burnet Institute, Melbourne, VIC, Australia Background: The use of 200 mg of doxycycline within 72 hours after condomless sex ("doxyPEP") has been shown to decrease the incidence of bacterial sexually transmitted infections (bSTI) in 2 randomized trials that enrolled cisgender men who have sex with men (MSM) and transgender women. However, limited data are available to inform the implementation of this novel STI prevention intervention in primary care settings. This report describes the doxyPEP roll-out in a Boston health center that specializes in primary care for sexual and gender minorities. Methods: Data from the clinic's electronic medical records were abstracted. Among all patients screened for a bSTI in 2023, bivariate logistic regression was used to compare characteristics of those receiving doxyPEP and those not receiving doxyPEP. DoxyPEP uptake (proportion receiving doxyPEP in 2023) among those with an active PrEP prescription in 2022-2023, PLHIV, and those tested for, and those diagnosed with, a bSTI in 2022 were also calculated. Results: Between January 26 and September 6, 2023, 1120 patients received a doxyPEP prescription. By March, monthly doxyPEP starts exceeded 100, with >250 patients initiating doxyPEP in June, 2023. Most doxyPEP patients were White (73.3%), non-Latinx (81.7%), and cisgender MSM (92.2%), with a mean age of 39.1 years. Among all patients screened for a bSTI in 2023 (N=4976), those receiving doxyPEP were more likely to be PrEP users (73.8% vs. 39.9%, odds ratio [OR]=4.25, 95%CI=3.67-4.93), have private insurance (85.4% vs. 71.3%, OR=2.37 [1.96-2.81]), have been diagnosed with a bSTI in 2022 (31.3% vs. 15.0%, OR=1.67 [1.42-1.98]), and less likely to be people living with HIV (PLHIV; 8.6% vs. 18.1%, OR=0.42 [0.34-0.53]) than those who did not receive doxyPEP. DoxyPEP users did not differ from non-users by age, race or ethnicity. DoxyPEP uptake was 24.1% (827/3427) among patients with an active PrEP prescription, 4.8% (96/2012) among PLHIV, 13.7% (900/6568) among those screened for a bSTI in 2022 and 24.7% (350/1416) among those diagnosed with a bSTI in 2022. Conclusion: Over 1,000 patients initiated doxyPEP in less than 6 months at a Boston health center. PrEP users were more likely to initiate doxyPEP than PLHIV, but most patients recently diagnosed with a bSTI had not received doxyPEP. The increased uptake among patients with private insurance compared to those with public insurance highlights the need for programs to facilitate doxyPEP access in an equitable manner. 1153 National Survey on the Use of Antibiotics as Sexually Transmitted Infection Prophylaxis in the US Michael W Traeger 1 , Douglas S. Krakower 1 , Kenneth H. Mayer 2 , Samuel M. Jenness 3 , Julia L. Marcus 1 1 Harvard Pilgrim Health Care Institute, Boston, MA, USA, 2 Fenway Health, Boston, MA, USA, 3 Emory University, Atlanta, GA, USA Background: Doxycycline postexposure prophylaxis (doxyPEP) is effective for preventing bacterial sexually transmitted infections (STIs) among people assigned male sex at birth. However, little is known about real-world use of antibiotics as STI prophylaxis, including prevalence and patterns of use, reasons for use, and potential user concerns. Methods: We conducted a national online survey in September 2023, with participants recruited via sexual networking apps used mainly by gay and bisexual men (GBM). Survey domains included sociodemographics, use of antibiotics as STI prophylaxis (including but not limited to doxyPEP), HIV/STI

1151 Doxy-PEP Effectiveness in Men Who Have Sex With Men (MSM) and Transgender Women (TGW) on HIV PrEP Oliver Bacon 1 , Robert P. Kohn 1 , David V. Glidden 2 , Madeline Sankaran 1 , Montica Levy 1 , Trang Q. Nguyen 1 , Stephanie E. Cohen 1 1 San Francisco Department of Public Health, San Francisco, CA, USA, 2 University of California San Francisco, San Francisco, CA, USA Background: Doxycycline post-exposure prophylaxis (doxy-PEP) reduced the risk of chlamydia (CT), gonorrhea (GC) and early syphilis (ES) in MSM and TGW in randomized trials. Little is known about doxy-PEP effectiveness on STI positivity outside of clinical trials. Methods: Starting 11/3/22, doxy-PEP was offered to patients receiving PrEP at San Francisco City Clinic who were eligible according to citywide guidelines. We assessed visit-level STI positivity at all visits among MSM and TGW PrEP patients who had at least one clinic visit pre (11/3/21-11/2/22) and post (11/3/22-11/2/23) guideline release. STI positivity was defined for GC and CT as the proportion of visits with a GC or CT test with at least one positive result, and for ES as the proportion of visits with a syphilis test that identified a new ES case. For those who ever initiated (i.e., were prescribed or self-reported use of) doxy-PEP (users), we compared STI positivity at visits pre and post doxy-PEP initiation. For those who did not initiate doxy-PEP (non-users), we compared STI positivity at visits pre and post 11/3/22. We compared the reduction in positivity for users vs. non-users using a generalized estimating equation model with robust variance to account for repeated measures. All data were routinely collected during clinic visits. Results: 506 patients had visits in both periods: 367 users and 139 non-users. Positivity decreased for CT (RR 0.10, 95% CI 0.05–0.21) significantly in users but not in non-users (RR 0.73, 95% CI 0.44–1.21) (Table); the decrease in positivity was significantly greater among users (p<.0001). ES positivity decreased significantly (RR 0.44, 95% CI 0.21–0.92) in users but not non-users (RR 0.68, 95% CI 0.20–2.30) (Table); these decreases were not significantly different (p=0.56). GC positivity decreased non-significantly for both groups (Table). Conclusion: Doxy-PEP significantly reduced positivity for CT and early syphilis among MSM and TGW receiving PrEP at an STI clinic. The difference was significantly greater than the reduction in CT seen in doxy-PEP non-users. There was no significant reduction in GC in doxy-PEP users or non-users. The reasons for reduction in CT positivity and new early syphilis cases in non-users is unclear and warrants further investigation.

Poster Abstracts

CROI 2024 375