CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

Conclusion: Countries should consider implementing re-testing before ART initiation as standard policy, particularly those moving to ‘treat all’. This will ensure the quality and effectiveness of HIV programmes, and save significant financial and human resources. 1032 MODELING THE COST-EFFECTIVENESS OF ASSISTED PARTNER NOTIFICATION FOR HIV IN KENYA Monisha Sharma 1 , Jennifer Smith 2 , Carey Farquhar 1 , Roger Ying 3 , Peter Cherutich 4 , Beatrice Wamuti 5 , Matthew R. Golden 1 , Felix Abuna 5 , Ruanne V. Barnabas 6 1 Univ of Washington, Seattle, WA, USA, 2 Imperial Coll London, London, UK, 3 Weill Cornell Med Coll, New York, NY, USA, 4 Ministry of Hlth, Nairobi, Kenya, 5 Kenyatta Natl Hosp, Nairobi, Kenya, 6 Univ of Washington, Seattle, USA Background: Assisted partner services (aPS) or provider notification for sexual partners of persons diagnosed HIV-positive can increase HIV testing and linkage to care in sub-Saharan Africa (SSA) and is a high yield strategy to identify persons with undiagnosed HIV. However, aPS is resource intensive and its cost-effectiveness in SSA is not well- evaluated. Methods: Using cost and effectiveness data from a randomized trial of aPS in Kenya, which found higher HIV testing in sexual partners in the aPS compared to control arm (41% vs. 9%), we parameterized a stochastic, dynamic mathematical HIV transmission model. The model incorporates partner concurrency, migration, coinfection with sexually transmitted infections, household structure, and health seeking behavior. We simulated 200 cohorts of 500,000 individuals and calculated the incremental cost-effectiveness of scaling up aPS in a region of western Kenya (formerly Nyanza Province) under different thresholds of antiretroviral (ART) initiation (CD4≤350, CD4≤500, and all HIV+ persons). Results: Over a 10 year time horizon with universal ART initiation for HIV+ persons, adding aPS to standard of care in western Kenya is projected to achieve 11% population coverage and reduce HIV infections by 2.7%. In sexual partners receiving aPS, HIV-related deaths were reduced by 7.6%. The incremental cost-effectiveness ratio (ICER) of implementing aPS is $1,568 USD (range $1,162-4,477) per disability-adjusted life year (DALY) averted. Task-shifting delivery of the intervention from healthcare professionals to community health workers decreases the ICER to $1,156 (range $762-2,050) per DALY averted. The task-shifting scenario falls below Kenya’s gross domestic product (GDP) per capita ($1,358) and is therefore considered very cost-effective, while the full program cost scenario is considered cost-effective under the higher threshold of 3-times Kenya’s GDP per capita. Cost-effectiveness results were robust to all three ART initiation thresholds while health benefits to aPS partners increased with expanding ART initiation criteria. Conclusion: APS is a cost-effective strategy to reduce HIV associated morbidity and mortality in western Kenya and similar settings. Task-shifting to community health workers will likely be necessary to increase program affordability. 1033 PREP TARGETING STRATEGIES FOR US ADOLESCENT SEXUAL MINORITY MALES: A MODELING STUDY Steven M. Goodreau 1 , Deven T. Hamilton 1 , Patrick Sullivan 2 , Samuel Jenness 2 , Rachel A. Kearns 2 , Li Yan Wang 3 , Richard Dunville 3 , Lisa C. Barrios 3 , Eli Rosenberg 2 1 Univ of Washington, Seattle, WA, USA, 2 Emory Univ, Atlanta, GA, USA, 3 CDC, Atlanta, GA, USA Background: Adolescent sexual minority males (ASMM) in the US have high HIV risk- one estimate is 7% prevalence at age 18-and thus may be good candidates for preexposure prophylaxis (PrEP). However, targeting PrEP to ASMM raises many issues, including identifying behavioral indications for prescription that are feasible to implement in clinical practice and which provide high epidemiological impact and efficiency. Methods: We modified our mathematical model of HIV transmission among adult MSM to focus on ASMM. We explored 7 scenarios for PrEP indications, based on age (13-18 vs. 16-18) and sexual behavior (planning to initiate anal intercourse [AI], already initiated AI, >5 or >10 condomless AI acts in the past 6 months). The median duration remaining on PrEP was 48 weeks, with adherence rates based on preliminary results from the ongoing ATN113 trial. We considered 5 levels of coverage. Outcomes were % of infections averted (PIA) and number needed to treat (NNT, person-years on PrEP per infection averted). Results: Our base scenario (40% coverage, indications = sexually active ASMM aged 16-18, PrEP initiated on average 6 months after debut) prevented 35.1% of infections, with an NNT of 33. Dropping eligibility age to 13 increases both the PIA (44.4%) and NNT (38) moderately. Initiating PrEP shortly before AI debut increased both further (48.3%, 41). Focusing on adolescents with the largest number of recent condomless AI acts yielded comparable PIA (35.2%-47.6% across scenarios), but much lower NNT values (27-32). Changing coverage demonstrated non-linearly increasing PIA values (20% coverage = 18.7% PIA, 60% coverage = 47.6% PIA), with slightly higher efficiency (lower NNT) for lower coverage (20% coverage = 33, 60% coverage = 36). Conclusion: Our model demonstrates that PrEP could significantly reduce HIV incidence among US ASMM. There are multiple ways to achieve high epidemiological impact and efficiency, although each involves challenges to both public health infrastructure (increasing PrEP coverage capacity for ASMM) and clinical practice (having clinicians assess relevant sexual histories). The strategies targeted to the highest risk ASMM achieve levels of efficiency similar to some scenarios considered in our recently published adult MSM model. These results underscore the importance of developing approaches to reach and screen ASMMwith the highest HIV risk, and to provide tailored support for their adherence and retention while on PrEP.

Poster and Themed Discussion Abstracts

1034 STI INCIDENCE AMONG MSM FOLLOWING HIV PREEXPOSURE PROPHYLAXIS: A MODELING STUDY Samuel Jenness 1 , Kevin Weiss 1 , Steven M. Goodreau 2 , Thomas Gift 3 , Harrell Chesson 3 , Karen W. Hoover 3 , Dawn K. Smith 3 , Patrick Sullivan 1 , Eli Rosenberg 1 1 Emory Univ, Atlanta, GA, USA, 2 Univ of Washington, Seattle, WA, USA, 3 CDC, Atlanta, GA, USA Background: Preexposure prophylaxis (PrEP) is highly effective for preventing HIV, but modest levels of risk compensation (RC) - such as reduced condom use - among men who have sex with men (MSM) have raised concerns about increased incidence of sexually transmitted infections (STIs). In contrast, CDC’s PrEP guidelines recommend biannual STI screening, which may reduce STI incidence by treating STIs (e.g., asymptomatic rectal infections) that often remain undiagnosed. We used modeling to estimate the effect of these two potentially counteracting phenomena.

CROI 2017 446