scholarly journals Disseminated Effects in Agent Based Models: A Potential Outcomes Framework and Application to Inform Pre-Exposure Prophylaxis Coverage Levels for HIV Prevention

2020 ◽  
Author(s):  
Ashley L Buchanan ◽  
S Bessey ◽  
William C Goedel ◽  
Maximilian King ◽  
Eleanor J Murray ◽  
...  
Keyword(s):  
Hiv Prevention ◽  
Hiv Incidence ◽  
Agent Based Models ◽  
Coverage Level ◽  
Sexual Network ◽  
Agent Based ◽  
Sex With Men ◽  
The Individual ◽  
Exposure Prophylaxis ◽  
Potential Outcomes Framework

Abstract Pre-exposure prophylaxis (PrEP) for HIV prevention may not only benefit the individual who uses it, but also their uninfected sexual risk contacts. We developed an agent-based model using a novel trial emulation approach to quantify disseminated effects of PrEP use among men who have sex with men in Atlanta, USA from 2015 to 2017. Components (subsets of agents connected through partnerships in a sexual network, but not sharing partnerships with any other agents) were first randomized to an intervention coverage level or control, then within intervention components, eligible agents were randomized to PrEP. We estimated direct and disseminated (indirect) effects using randomization-based estimators and reported corresponding 95% simulation intervals across scenarios ranging from 10% to 90% coverage in the intervention components. A population of 11,245 agents was simulated with an average of 1,551 components identified. Comparing agents randomized to PrEP in 70% coverage components to control agents, there was a 15% disseminated risk reduction in HIV incidence (95% simulation intervals = 0.65, 1.05). Individuals not on PrEP may receive a protective benefit by being in a sexual network with higher PrEP coverage. Agent-based models are useful to evaluate possible direct and disseminated effects of HIV prevention modalities in sexual networks.

scholarly journals Pre-Exposure Prophylaxis (PrEP) Uptake among Black Men Who Have Sex with Men (BMSM) in the Southern U.S.

2021 ◽  
Vol 18 (18) ◽  
pp. 9715
Author(s):  
Oluwafemi Adeagbo ◽  
Sayward Harrison ◽  
Shan Qiao ◽  
Xiaoming Li
Keyword(s):  
Hiv Prevention ◽  
Black Men ◽  
Healthcare Providers ◽  
Rapid Expansion ◽  
Hiv Care ◽  
Hiv Incidence ◽  
Interdisciplinary Approaches ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
The U.S

Black men who have sex with men (BMSM) living in the United States (U.S.) South are disproportionately affected by HIV and experience significant disparities in HIV incidence, access to HIV care, and prevention across ages and socio-economic statuses. The aim of this commentary is to critically review current literature on the state of PrEP use among BMSM in the U.S. South, including identifying barriers and facilitators to PrEP use in order to inform intervention development. Extant literature shows that despite the documented benefits of PrEP as an effective HIV-prevention method, its uptake among BMSM is limited across the U.S. South. Common barriers to PrEP uptake included stigma, homophobia, mistrust of healthcare systems, negative attitudes from healthcare providers, access and transportation issues, poverty, and misinformation about PrEP. These barriers are likely to have been further exacerbated by the COVID-19 pandemic. Limited access to PrEP and other HIV-prevention programs, such as HIV testing, post-exposure prophylaxis (PEP), and condoms for BMSM are likely increase HIV incidence in this community. Moreover, the rapid expansion of telehealth services during the COVID-19 period may offer increased opportunity to scale-up PrEP through telehealth interventions, especially if in-person services remain limited due to pandemic precautions. Given the intersectional barriers that limit the access and uptake of PrEP among BMSM, we suggest that tailored programs or interventions that seek to address PrEP disparities among Southern BMSM should adopt intersectional and interdisciplinary approaches to better understand the complex challenges of scaling up PrEP. More studies are needed to investigate the impact of COVID-19 on HIV-prevention services among BMSM and to understand how to co-develop—with the BMSM community and healthcare providers—culturally acceptable interventions to reduce the identified challenges using intersectional and interdisciplinary approaches.

scholarly journals Birth Cohort Variations Across Functional Knowledge of HIV Prevention Strategies, Perceived Risk, and HIV-Associated Behaviors Among Gay, Bisexual, and Other Men Who Have Sex With Men in the United States

2018 ◽  
Vol 12 (6) ◽  
pp. 1824-1834 ◽  
Author(s):  
Akshay Sharma ◽  
Erin M. Kahle ◽  
Stephen P. Sullivan ◽  
Rob Stephenson
Keyword(s):  
Hiv Prevention ◽  
Birth Cohort ◽  
Perceived Risk ◽  
The United States ◽  
Prevention Strategies ◽  
The Past ◽  
Hiv Prevention Strategies ◽  
Functional Knowledge ◽  
Sex With Men ◽  
Exposure Prophylaxis

Gay, bisexual, and other men who have sex with men (GBMSM) in the United States remain heavily impacted by HIV. The purpose of this study was to describe intergenerational differences in functional knowledge of HIV prevention strategies, perceived risk, recent condomless anal sex (CAS), and HIV testing behavior. Eight hundred sexually active GBMSM were recruited via Facebook from August to September 2015, and administered a Web-based survey which included 12 multiple-choice questions to elicit data regarding functional knowledge of different HIV prevention approaches (e.g., condom use, pre-exposure prophylaxis post-exposure prophylaxis, treatment as prevention, circumcision). Cumulative logit and multivariable logistic models were formulated to examine birth cohort variations across four analytic outcomes. Younger generations were significantly more knowledgeable, as were GBMSM with higher education. Non-Hispanic non-White GBMSM and those reporting a bisexual/other sexual orientation had lower functional knowledge. Younger generations were equally concerned about contracting HIV as their older counterparts. Perceived risk was significantly higher among non-Hispanic non-White and Hispanic GBMSM, but lower among those with higher education and those in a relationship. Finally, birth cohort variations with respect to engaging in CAS with ≥2 men in the past 3 months and testing for HIV in the past year were not markedly pronounced. Younger GBMSM might be more knowledgeable about HIV prevention strategies compared to their predecessors, but are equally concerned about contracting HIV. Researchers and practitioners should consider intergenerational and other demographic differences while designing multifaceted HIV prevention programs for GBMSM.

scholarly journals Southern African guidelines for the safe use of pre-exposure prophylaxis in men who have sex with men who are at risk for HIV infection

2012 ◽  
Vol 13 (2) ◽  
Author(s):  
Southern African HIV Clinicians Society Consensus Committee
Keyword(s):  
At Risk ◽  
Renal Function ◽  
Hiv Prevention ◽  
Hepatitis B ◽  
Hiv Infection ◽  
Creatinine Clearance ◽  
Fixed Dose ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
Hiv Negative

Background. The use of oral antiretrovirals to prevent HIV infection among HIV-negative men who have sex with men (MSM) has been shown to be safe and efficacious. A large, randomised, placebo-controlled trial showed a 44% reduction in the incidence of HIV infection among MSM receiving a daily oral fixed-dose combination of tenofovir disoproxil fumarate and emtricitabine (Truvada) in combination with an HIV prevention package. Improved protection was seen with higher levels of adherence. Aim. The purpose of this guideline is to: (i) explain what pre-exposure prophylaxis (PrEP) is; (ii) outline current indications for its use; (iii) outline steps for appropriate client selection; and (iv) provide guidance for monitoring and maintaining clients on PrEP. Method. PrEP is indicated for HIV-negative MSM who are assessed to be at high risk for HIV acquisition and who are willing and motivated to use PrEP as part of a package of HIV prevention services (including condoms, lubrication, sexually transmitted infection (STI) management and risk reduction counselling). Recommendations. HIV testing, estimation of creatinine clearance and STI and hepatitis B screening are recommended as baseline investigations. Daily oral Truvada, along with adherence support, can then be prescribed for eligible MSM. PrEP should not be given to MSM with abnormal renal function, nor to clients who are unmotivated to use PrEP as part of an HIV prevention package; nor should it be commenced during an acute viral illness. Three-monthly follow-up visits to assess tolerance, renal function, adherence and ongoing eligibility is recommended. Six-monthly STI screens and annual creatinine levels to estimate creatinine clearance are recommended. Hepatitis B vaccination should be provided to susceptible clients. Gastro-intestinal symptoms and weight loss are common side-effects, mostly experienced for the first 4 - 8 weeks after initiating PrEP. There is a risk of the development of antiretroviral resistance among those with undiagnosed acute HIV infection during PrEP initiation and among those with sub-optimal adherence who become HIV infected while on PrEP. Risk compensation (increasing sexual behaviours that can result in exposure to HIV) while on PrEP may become a concern, and clinicians should continue to support MSM clients to continue to use condoms, condom-compatible lubrication and practice safer sex. Research is ongoing to assess optimum dosing regimens, potential long-term effects and alternative PrEP medications. Recommendations for the use of PrEP among other at-risk individuals, and the components of these recommendations, will be informed by future evidence. S Afr J HIV Med 2012;13(2):40-55.

scholarly journals 1701. Added Benefits of Pre-exposure Prophylaxis Use on HIV Incidence with Minimal Changes in Efficiency in the Context of High Treatment Engagement among Men Who Have Sex with Men

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S833-S833
Author(s):  
Alyson L Singleton ◽  
Brandon D Marshall ◽  
Xiao Zang ◽  
Amy S Nunn ◽  
William C Goedel
Keyword(s):  
African American ◽  
Hiv Infection ◽  
Hiv Transmission ◽  
Treatment Engagement ◽  
Hiv Incidence ◽  
Black African ◽  
African American Msm ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
High Treatment

Abstract Background Although there is ongoing debate over the need for substantial increases in PrEP use when antiretroviral treatment confers the dual benefits of reducing HIV-related morbidity and mortality and the risk of HIV transmission, no studies to date have quantified the potential added benefits of PrEP use in settings with high treatment engagement across variable sub-epidemics in the United States. Methods We used a previously published agent-based network model to simulate HIV transmission in a dynamic network of 17,440 Black/African American and White MSM in Atlanta, Georgia from 2015 to 2024 to understand how the magnitude of reductions in HIV incidence attributable to varying levels of PrEP use (0–90%) changes in potential futures where high levels of treatment engagement (i.e. the UNAIDS ‘90-90-90’ goals and eventual ‘95-95-95’ goals) are achieved and maintained, as compared to current levels of treatment engagement in Atlanta (Figure 1). Model inputs related to HIV treatment engagement among Black/African American and White men who have sex with men in Atlanta. A comparison of current levels of treatment engagement (Panel A) to treatment engagement at ‘90-90-90’ (Panel B) and ‘95-95-95’ goals (Panel C). Results Even at achievement and maintenance of ‘90-90-90’ goals, 75% PrEP coverage reduced incidence rates by an additional 67.9% and 74.2% to 1.53 (SI: 1.39, 1.70) and 0.355 (SI: 0.316, 0.391) per 100 person-years for Black/African American and White MSM, respectively (Figure 2), compared to the same scenario with no PrEP use. Additionally, an increase from 15% PrEP coverage to 75% under ‘90-90-90’ goals only increased person-years of PrEP use per HIV infection averted, a measure of efficiency of PrEP, by 8.1% and 10.5% to 26.7 (SI: 25.6, 28.0) and 73.3 (SI: 70.6, 75.7) among Black/African American MSM and White MSM, respectively (Figure 3). Overall (Panel A) and race-stratified (Panel B and Panel C) marginal changes in HIV incidence over ten years among Black/African American and White men who have sex with men in Atlanta across scenarios of varied levels of treatment engagement among agents living with HIV infection and levels of pre-exposure prophylaxis use among HIV-uninfected agents. Note: All changes are calculated within each set of treatment scenarios relative to a scenario where no agents use pre-exposure prophylaxis. Person-years of pre-exposure prophylaxis use per HIV infection averted among Black/African American (Panel A) and White (Panel B) men who have sex with men in Atlanta across scenarios of varied levels of treatment engagement among agents living with HIV infection and levels of pre-exposure prophylaxis use among HIV-uninfected agents. Note: The number of HIV infections averted is calculated within each set of treatment scenarios relative to a scenario where no agents use pre-exposure prophylaxis. Conclusion Even in the context of high treatment engagement, substantial expansion of PrEP use still contributes to meaningful decreases in HIV incidence among MSM with minimal changes in person-years of PrEP use per HIV infection averted, particularly for Black/African American MSM. Disclosures All Authors: No reported disclosures

scholarly journals PrEP in Prisons: HIV prevention in incarcerated populations

2019 ◽  
Vol 16 (2) ◽  
pp. 199-206
Author(s):  
Jordan Parsons ◽  
Chelsea Cox
Keyword(s):  
Hiv Prevention ◽  
Harm Reduction ◽  
New Approach ◽  
Content Type ◽  
Harm Reduction Intervention ◽  
Access To Health ◽  
Prevention Interventions ◽  
High Risk Populations ◽  
Sex With Men ◽  
Exposure Prophylaxis

Purpose The purpose of this paper is to discuss the possibility of using pre-exposure prophylaxis (PrEP) as an HIV harm reduction intervention in prisons. PrEP is primarily discussed in relation to men who have sex with men (MSM), meaning other high-risk populations, such as prisoners, are often side-lined. The authors wanted to consider how it could prove beneficial beyond the MSM community. Design/methodology/approach First, the authors discuss whether the common objections to existing HIV harm reduction interventions in prisons, such as needle exchanges, are applicable to PrEP. The authors then apply common objections to the provision of PrEP in the general population to the provision of PrEP in a prison context in order to assess their strength. Finally, the authors discuss what the authors anticipate to be a key objection to PrEP in prisons: post-incarceration access. Findings The authors argue that both sets of common objections considered are easily refuted in the case of PrEP in prisons. The unique setting and nature of the intervention are such that it is without immediately apparent flaws. In addressing post-incarceration access, the authors suggest that a longitudinal consideration of a prisoner’s HIV risk undermines the objection. Originality/value This discussion is of importance due to the significantly heightened risk of HIV infection prisoners are subject to. Not only do effective HIV prevention interventions in prisons contribute to fair access to health for incarcerated individuals, but also to the wider fight against HIV. The authors demonstrate that PrEP has potential as a new approach and call for further research in this area.

scholarly journals Improving the impact of HIV pre-exposure prophylaxis implementation in small urban centers among men who have sex with men: An agent-based modelling study

PLoS ONE ◽  
2018 ◽  
Vol 13 (7) ◽  
pp. e0199915 ◽  
Author(s):  
Jason R. Gantenberg ◽  
Maximilian King ◽  
Madeline C. Montgomery ◽  
Omar Galárraga ◽  
Mattia Prosperi ◽  
...  
Keyword(s):  
Urban Centers ◽  
Agent Based ◽  
Agent Based Modelling ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
The Impact ◽  
Modelling Study

scholarly journals Using a network-based approach and targeted maximum likelihood estimation to evaluate the effect of adding pre-exposure prophylaxis to an ongoing test-and-treat trial

2017 ◽  
Vol 14 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Laura Balzer ◽  
Patrick Staples ◽  
Jukka-Pekka Onnela ◽  
Victor DeGruttola
Keyword(s):  
Maximum Likelihood ◽  
High Risk ◽  
Likelihood Estimation ◽  
Hiv Incidence ◽  
Test And Treat ◽  
Universal Test ◽  
Universal Test And Treat ◽  
Targeted Maximum Likelihood ◽  
The Individual ◽  
Exposure Prophylaxis

Background: Several cluster-randomized trials are underway to investigate the implementation and effectiveness of a universal test-and-treat strategy on the HIV epidemic in sub-Saharan Africa. We consider nesting studies of pre-exposure prophylaxis within these trials. Pre-exposure prophylaxis is a general strategy where high-risk HIV– persons take antiretrovirals daily to reduce their risk of infection from exposure to HIV. We address how to target pre-exposure prophylaxis to high-risk groups and how to maximize power to detect the individual and combined effects of universal test-and-treat and pre-exposure prophylaxis strategies. Methods: We simulated 1000 trials, each consisting of 32 villages with 200 individuals per village. At baseline, we randomized the universal test-and-treat strategy. Then, after 3 years of follow-up, we considered four strategies for targeting pre-exposure prophylaxis: (1) all HIV– individuals who self-identify as high risk, (2) all HIV– individuals who are identified by their HIV+ partner (serodiscordant couples), (3) highly connected HIV– individuals, and (4) the HIV– contacts of a newly diagnosed HIV+ individual (a ring-based strategy). We explored two possible trial designs, and all villages were followed for a total of 7 years. For each village in a trial, we used a stochastic block model to generate bipartite (male–female) networks and simulated an agent-based epidemic process on these networks. We estimated the individual and combined intervention effects with a novel targeted maximum likelihood estimator, which used cross-validation to data-adaptively select from a pre-specified library the candidate estimator that maximized the efficiency of the analysis. Results: The universal test-and-treat strategy reduced the 3-year cumulative HIV incidence by 4.0% on average. The impact of each pre-exposure prophylaxis strategy on the 4-year cumulative HIV incidence varied by the coverage of the universal test-and-treat strategy with lower coverage resulting in a larger impact of pre-exposure prophylaxis. Offering pre-exposure prophylaxis to serodiscordant couples resulted in the largest reductions in HIV incidence (2% reduction), and the ring-based strategy had little impact (0% reduction). The joint effect was larger than either individual effect with reductions in the 7-year incidence ranging from 4.5% to 8.8%. Targeted maximum likelihood estimation, data-adaptively adjusting for baseline covariates, substantially improved power over the unadjusted analysis, while maintaining nominal confidence interval coverage. Conclusion: Our simulation study suggests that nesting a pre-exposure prophylaxis study within an ongoing trial can lead to combined intervention effects greater than those of universal test-and-treat alone and can provide information about the efficacy of pre-exposure prophylaxis in the presence of high coverage of treatment for HIV+ persons.

scholarly journals Willingness to use pre-exposure prophylaxis (PrEP) for HIV prevention among men who have sex with men (MSM) in Malaysia: findings from a qualitative study

2017 ◽  
Vol 20 (1) ◽  
pp. 21899 ◽  
Author(s):  
Adam Bourne ◽  
Matteo Cassolato ◽  
Clayton Koh Thuan Wei ◽  
Bangyuan Wang ◽  
Joselyn Pang ◽  
...  
Keyword(s):  
Hiv Prevention ◽  
Qualitative Study ◽  
Sex With Men ◽  
Willingness To Use ◽  
Exposure Prophylaxis
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