CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

1194 HIV Recency Surveillance Improves PrEP Uptake: Evaluation With Synthetic Controls Sara Wallach 1 , Matthew R. Lamb 1 , Claire Steiner 2 , Eugenie Poirot 2 , Samkelo Simelane 3 , Dumile Sibandze 4 , Vusie Lokotfwako 4 , Aisha Pasha 2 , Harriet Nuwagaba-Biribonwoha 3 , Yen T. Duong 2 , Melissa Arons 5 , Munyaradzi Pasipamire 6 , Suzue Saito 2 , Lenhle Dube 4 1 Columbia University, New York, NY, USA, 2 ICAP at Columbia University, New York, NY, USA, 3 ICAP at Columbia University, Mbabane, Eswatini, 4 Ministry of Health, Mbabane, Eswatini, 5 Centers for Disease Control and Prevention, Atlanta, GA, USA, 6 Centers for Disease Control and Prevention, Mbabane, Eswatini Background: Eswatini's HIV-1 Recent Infection Surveillance (EHRIS) program, implemented since 2019, identifies trends in recent and long-term HIV infections. EHRIS flags hotspots (HIV testing centers with ≥4 monthly recent infections) for public health responses focused on fidelity to index testing, partner notification, and linkage to PrEP for contacts testing negative. We used synthetic control methods (SCM) to evaluate the impact of this public health response on PrEP enrollment. Methods: We used October 2019-December 2022 data to conduct a difference in-difference analysis with SCM to compare trends in PrEP enrollment between intervention (n=9) and non-intervention facilities (n=93) pre- and post intervention. SCM is a data-driven technique that manufactures a weighted synthetic control (SC) from a pool of possible controls to best approximate pre-treatment trends observed in the intervention unit(s). The intervention point was August 1, 2020. Pre-intervention trends were estimated using facility level characteristics associated with historic PrEP enrollment trends. To ensure the SC did not create differences unrelated to the intervention, we completed an "in-time" placebo test, using March 1, 2021 as our fake intervention time. Results: Similar pre-intervention trends were observed in the intervention clinics and the SC (Figure 1a). The average treatment effect for the post intervention period was 10.2 additional PrEP enrollees a month, from an average of 6.7 in the SC to 16.9 in the intervention (p=0.004). Six months post intervention, PrEP enrollment increased in both groups but increased more in intervention facilities; this was sustained during the rest of the study period. Between April-December 2022, intervention clinics averaged roughly twice the monthly PrEP enrollment of the SC. Decreases in June 2021 in both arms occurred during a period of political unrest. The mean squared prediction error for the model was 3.41, demonstrating adequate predictive accuracy of the model for program data. The placebo test (Figure 1b) showed no difference in outcome trends unrelated to the intervention. Conclusion: EHRIS-informed interventions resulted in increased and sustained PrEP enrollment in intervention facilities in Eswatini compared to the SC. Recency data strengthened linkages to PrEP services among HIV negative contacts and increased PrEP uptake.

education levels. These results demonstrate that having a sexual partner who is HIV positive is a strong predictor for ever having used PrEP. More efforts, however, are needed to increase uptake in other populations that are at substantial risk for HIV infection, such as persons with multiple sexual partners and low condom use.

1193 Sexual Health Outcomes Among Daily and On-Demand Oral PrEP Users in China Chunyan Li 1 , Zhuoheng Yin 2 , Weiming Tang 3 , Songjie Wu 4 , Quanmin Li 5 , Yifan Dai 2 , Chengxin Fan 2 , Ke Liang 4 , Linghua Li 5 , Wu Sun 5 , Joseph D. Tucker 3 , Haojie Huang 6 , Jonathan Lio 7 , Aniruddha Hazra 7 , Renslow Sherer 7 1 University of Tokyo, Tokyo, Japan, 2 University of North Carolina, Guangzhou, China, 3 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 4 Zhongnan Hospital of Wuhan University, Guangzhou, China, 5 Guangzhou Eighth People's Hospital, Guangzhou, China, 6 Wuhan Tongxing LGBT Center, Guangzhou, China, 7 University of Chicago, Chicago, IL, USA Background: Longitudinal data on sex behaviors and STIs among Chinese PrEP users is limited. Here we reported self-reported newly diagnosed STIs and sex behaviors among MSM who are on daily and on-demand PrEP regimens in China. Methods: MSM in Wuhan and Guangzhou were recruited by online ads, clinic flyers, and community referrals to a PrEP demonstration trial. Behavioral survey data were collected at baseline and quarterly follow-ups over 12 months (M3, M6, M9, M12). MSM were prescribed TDF/TFC as oral PrEP and could opt for daily or on-demand regimens. Descriptive analysis and multivariable logistic regressions were conducted in Stata 15.0. Results: From September 2021 to September 2023, 1,209 MSM were enrolled and initiated PrEP (mean age=28.0, IQR 24.0-31.4), with 164 (16.0%) dropping out before the trial ended. About half of the participants opted for daily PrEP, while the rest chose on-demand (2+1+1). MSM reporting not having penetrative sex during the three months increased from 3.9% at baseline to 11.1% at M12 (p<0.001). Regarding condom use behaviors, we observed a notable increase of MSM reporting "never to seldom using condoms in sex" at M9 & M12 (17.3%, 18.6%) compared to baseline (10.1%) (p<0.001). The proportion of people having sex under the influence of substance use (predominantly alcohol & nitrate inhalants) remained persistently high (52.8% at baseline vs. 46.0% at M12). The proportion of people who self-reported any STI diagnosed in the past 3 months remained 4.9 to 8.0% during the study period, with the syphilis prevalence stabling from 3.6-5.0%. Multivariate analyses indicated that PrEP dosing strategies were not associated with newly diagnosed STIs, condom use habits change, or sex under the influence of substances over time. However, MSM of higher income levels (OR=3.9, 95% CI: 1.7-9.1) and those who seldom to not use condoms (OR=3.4, 95% CI: 1.8-6.7) were more likely to report having sex while using substances. Conclusion: Our study results showed comparable impact on risks of STIs or sex behavior changes between once-daily and on-demand oral PrEP dosing strategies. Nonetheless, the observed increased number of MSM not having sex, less condom use habits, and persistent prevalence of engaging in sex activities under the influence of substance use underscore the evolving sexual behavior patterns within Chinese MSM PrEP users. Engaging PrEP users in routine testing and safe sex counseling is critical to the holistic health promotion of MSM communities.

Poster Abstracts

1195 Expanding Event-Driven PrEP to People Assigned Male at Birth Across 3 African Countries Lirica Nishimoto 1 , Augustine Amedzi 2 , Makhosazana Matsebula 3 , Bhekizitha Sithole 3 , Rachel Lyimo 4 , Huckins Reeves 4 , Gertrude Nunoo 2 , Ncamsile Dlamini 3 , Gift Kamanga 4 , Michael Odo 4 , Nana Fosua Clement 4 , Tiffany Lillie 1 , Christa Fischer-Walker 1 , Chris Akolo 1 1 FHI 360 , Washington, DC, USA, 2 FHI 360 , Accra, Ghana, 3 FHI 360 , Mbabane, Eswatini, 4 FHI 360 , Monrovia, Liberia Background: In 2022, World Health Organization recommended the expansion of event-driven pre-exposure prophylaxis (ED-PrEP) to prevent HIV not only among men who have sex with men (MSM) but also all people assigned male at birth (AMAB) who are not using estradiol-based exogenous hormones. The USAID- and PEPFAR-funded Meeting Targets and Maintaining Epidemic Control (EpiC) project offered ED-PrEP as another option to oral daily PrEP to people AMAB not using estradiol-based exogenous hormones across three sub-Saharan African countries.

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