Impact of the Centers for Disease Control's HIV Preexposure Prophylaxis Guidelines for Men Who Have Sex With Men in the United States.
ABSTRACT: BACKGROUND:?Preexposure prophylaxis (PrEP) is effective for preventing human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) within trial settings. Population impact will depend on clinical indications for PrEP initiation, coverage levels, and drug adherence. No modeling studies have estimated the impact of clinical practice guidelines for PrEP issued by the Centers for Disease Control and Prevention (CDC). METHODS:?Mathematical models of HIV transmission among MSM were used to estimate the percentage of infections averted (PIA) and the number needed to treat (NNT) under behavioral indications of the CDC's PrEP guidelines. We modeled the contribution of these indications while varying treatment coverage and adherence. RESULTS:?At 40% coverage of indicated MSM over the next decade, application of CDC guidelines would avert 1162 infections per 100 000 person-years, 33.0% of expected infections. The predicted NNT for the guidelines would be 25. Increasing coverage and adherence jointly raise the PIA, but reductions to the NNT were associated with better adherence only. CONCLUSIONS:?Implementation of CDC PrEP guidelines would result in strong and sustained reductions in HIV incidence among MSM in the United States. The guidelines strike a good balance between epidemiological impact (PIA) and efficiency (NNT) at plausible scale-up levels. Adherence counseling could maximize public health investment in PrEP by decreasing the NNT.
Project description:<h4>Background</h4>Preexposure prophylaxis (PrEP) is highly effective for preventing human immunodeficiency virus (HIV) infection, but risk compensation (RC) in men who have sex with men (MSM) raises concerns about increased sexually transmitted infections (STIs). The Center for Disease Control and Prevention's (CDC's) PrEP guidelines recommend biannual STI screening, which may reduce incidence by treating STIs that would otherwise remain undiagnosed. We investigated these two counteracting phenomena.<h4>Methods</h4>With a network-based mathematical model of HIV, Neisseria gonorrhoeae (NG), and Chlamydia trachomatis (CT) transmission dynamics among MSM in the United States, we simulated PrEP uptake following the prescription indications and HIV/STI screening recommendations in the CDC guidelines. Scenarios varied PrEP coverage (the proportion of MSM indicated for PrEP who received it), RC (a reduction in the per-act probability of condom use), and the STI screening interval.<h4>Results</h4>In our reference scenario (40% coverage, 40% RC), 42% of NG and 40% of CT infections would be averted over the next decade. A doubling of RC would still result in net STI prevention relative to no PrEP. STIs declined because PrEP-related STI screening resulted in a 17% and 16% absolute increase in the treatment of asymptomatic and rectal STIs, respectively. Screening and timely treatment at quarterly vs biannual intervals would reduce STI incidence an additional 50%.<h4>Conclusions</h4>Implementation of the CDC PrEP guidelines while scaling up PrEP coverage could result in a significant decline in STI incidence among MSM. Our study highlights the design of PrEP not only as antiretroviral medication but as combination HIV/STI prevention incorporating STI screening.
Project description:BACKGROUND:Identification of clients at greatest risk of acquiring HIV is critical for preexposure prophylaxi (PrEP) implementation. Young black MSM (YBMSM) have high incidence of HIV. We examined published guidelines in identifying eligible PrEP candidates, including seroconverters, in a representative cohort of YBMSM. METHODS:The uConnect cohort included YBMSM aged 16-29 years during PrEP roll-out in Chicago from 2013 and 2016. YBMSM with indications for PrEP were determined using Center for Disease Control and Prevention (CDC) guidelines, the HIV incidence risk index for MSM (HIRI-MSM) scoring tool, and Gilead recommendations with calculation of sensitivities, specificities, and area under the curve (AUC) for HIV seroconversion over 18 months. Incidence rate ratios (IRRs) using Poisson regression were modeled to compare individual and network factors associated with seroconversion. RESULTS:In the study cohort, 300 HIV uninfected YBMSM contributed 390.4 person-years of follow-up [mean age (SD), 22.3 years (3.07)]. HIV incidence was 8.5 cases per 100 person-years (95% confidence interval, 6.0-11.9). One network factor was associated with seroconversion: having partners more than 10 years older (IRR?=?4.4, 95% confidence interval, 1.6-11.8). Overall, 49% of the cohort had an indication for PrEP using CDC guidelines; 72% using HIRI-MSM, and 86% using Gilead recommendations. HIV seroconverters (n?=?33) were identified as PrEP eligible prior to seroconversion with sensitivities/AUCs for CDC (52%/0.51), HIRI-MSM (85%/0.57), and Gilead guidelines (94%/0.54). CONCLUSION:Low sensitivity of CDC guidelines and limited AUC of HIRI-MSM and Gilead screening tools are of concern for PrEP implementation among most at risk populations such as YBMSM. Consideration of demographics, local epidemiology, and network factors may better guide identification of clients who could benefit most from PrEP.
Project description:<h4>Objective</h4>We aimed to determine the effectiveness of various preexposure prophylaxis (PrEP) prescription strategies for African-American women impacted by mass incarceration within an urban setting.<h4>Design</h4>An agent-based model was utilized to evaluate prevention strategies in an efficient, ethical manner. By defining agents, their characteristics and relationships, we assessed population-level effects of PrEP on HIV incidence.<h4>Methods</h4>We tested hypothetical PrEP prescription strategies within a simulation representing the African-American population of Philadelphia, Pennsylvania. Four strategies were evaluated: PrEP for women meeting CDC indicators regarding partner characteristics, PrEP for women with a recently incarcerated male partner, PrEP for women with a recently released male partner and couples-based PrEP at time of release. Interventions occurred alongside scale-up of HAART. We evaluated reductions in HIV transmissions, the number of persons on PrEP needed to avert one HIV transmission (NNT) and the resulting proportions of people on PrEP.<h4>Results</h4>Scenarios prescribing PrEP based on criminal justice system involvement reduced HIV transmissions. The NNT ranged from 147 (couples-based scenario) to 300 (recently released scenario). The percentage of the female population covered by PrEP at any one time ranged from 0.14% (couples-based) to 10.8% (CDC-based). CDC-guideline scenarios were consistently less efficient compared to the justice-involved interventions.<h4>Conclusion</h4>Expanding PrEP for African-American women and their male partners affected by incarceration should be considered in national HIV prevention goals and correctional facilities leveraged as intervention sites. Partner characteristics in the current CDC indications may be more effective and efficient if guidelines considered criminal justice involvement.
Project description:BACKGROUND:Oral pre-exposure prophylaxis (PrEP) is a highly effective option for HIV prevention. To realize the full benefit of PrEP at the population level, uptake must reach those at the greatest risk of HIV acquisition. Guidance published by Centers for Disease Control and Prevention (CDC) suggests that the number of individuals with indications for PrEP is 1.1-1.2 million nationally based on survey data of key populations and local transmission patterns. We applied these estimates at state and county levels to determine the number of individuals who might benefit from PrEP locally and compared our estimates to CDC-published estimates for Colorado. OBJECTIVE:This analysis aimed to produce estimates of key populations with indications for PrEP in Colorado as a whole and by county type. These estimates will be used for public health strategic planning for HIV prevention goals at the state and county jurisdictional levels. METHODS:Colorado population estimates were obtained from the state demography office, which utilizes US decennial census data and input from county and local agencies to forecast the population. We limited our analysis to adults aged 18-59 years to be consistent with CDC methodology for PrEP estimates. We performed a literature review to define the best population-level percentages to determine numbers of HIV-negative men who have sex with men (MSM) and people who inject drugs (PWID) in Colorado. These percentages were applied to the state and to each county by its rural-urban designation. Finally, CDC-derived percentages of MSM and PWID with indications for PrEP were applied to these estimates to determine numbers of MSM and PWID who may benefit from PrEP use. RESULTS:In 2017, 3,252,648 adults aged 18-59 years were living in Colorado. By applying published estimates of percentages of men who had sex with other men in the past 12 months, we determined that 41,353-49,624 adult males could be considered sexually active MSM. We estimated that 9758-13,011 adults aged 18-59 years were likely to have injected drugs in the past 12 months. By accounting for numbers of people living with HIV in those categories and applying the CDC PrEP percentages of MSM and PWID with indications for PrEP nationally, we estimated that 8792-12,528 MSM and PWID in Colorado had indications for PrEP; this number is smaller than that estimated by CDC, although within the lower CI limit. CONCLUSIONS:By employing a simple framework consisting of census data, literature review, population estimates, and national estimates for PrEP indicators, we derived estimates for potential PrEP use in our state. Statewide estimates of key populations by state and county type will enable health officials to set informed goals and track progress toward optimizing PrEP uptake. This formula may be applicable to other states with similar epidemics and resources.?.
Project description:Pre-exposure prophylaxis (PrEP) effectively reduces human immunodeficiency virus (HIV) transmission. We aimed to estimate the impact of different PrEP prioritization strategies among Black and Latino men who have sex with men (MSM) in the United States, populations most disproportionately affected by HIV. We developed an agent-based simulation to model the HIV epidemic among MSM. Individuals were assigned an HIV incidence risk index (HIRI-MSM) based on their sexual behavior. Prioritization strategies included PrEP use for individuals with HIRI-MSM ≥10 among all MSM, all Black MSM, young (≤25 years) Black MSM, Latino MSM, and young Latino MSM. We estimated the number needed to treat (NNT) to prevent one HIV infection, reductions in prevalence and incidence, and subsequent infections in non-PrEP users avoided under these strategies over 5 years (2016-2020). Young Black MSM eligible for PrEP had the lowest NNT (NNT = 10) followed by all Black MSM (NNT = 33) and young Latino MSM (NNT = 35). All Latino MSM and all MSM had NNT values of 63 and 70, respectively. Secondary infection reduction with PrEP was the highest among young Latino MSM (53.2%) followed by young Black MSM (37.8%). Targeting all MSM had the greatest reduction in prevalence (14.7% versus 2.9%-3.9% in other strategies) and incidence (49.4% versus 9.4%-13.9% in other groups). Using data representative of the United States MSM population, we found that a strategy of universal PrEP use by MSM was most effective in reducing HIV prevalence and incidence of MSM. Targeted use of PrEP by Black and Latino MSM, however, especially those ≤25 years, had the greatest impact on HIV prevention.
Project description:<h4>Introduction</h4>Once-daily tenofovir/emtricitabine-based pre-exposure prophylaxis (PrEP) can reduce HIV acquisition in men who have sex with men (MSM), by 44% in the iPrEx trial, and reaching up to 99% with high adherence. We examined the potential population-level impact and cost-effectiveness of different PrEP implementation strategies.<h4>Methods</h4>We developed a dynamic, stochastic compartmental model of HIV transmission among the estimated 57,400 MSM in Toronto, Canada. Parameterization was performed using local epidemiologic data. Strategies examined included (1) uniform PrEP delivery versus targeting the highest risk decile of MSM (with varying coverage proportions); (2) increasing PrEP efficacy as a surrogate of adherence (44% to 99%); and (3) varying HIV test frequency (once monthly to once yearly). Outcomes included HIV infections averted and the incremental cost ($CAD) per incremental quality-adjusted-life-year (QALY) gained over 20 years.<h4>Results</h4>Use of PrEP among all HIV-uninfected MSM at 25, 50, 75 and 100% coverage prevented 1970, 3427, 4317, and 4581 infections, respectively, with cost/QALY increasing from $500,000 to $800,000 CAD. Targeted PrEP for the highest risk MSM at 25, 50, 75 and 100% coverage prevented 1166, 2154, 2816, and 3012 infections, respectively, with cost/QALY ranging from $35,000 to $70,000 CAD. Maximizing PrEP efficacy, in a scenario of 25% coverage of high-risk MSM with PrEP, prevented 1540 infections with a cost/QALY of $15,000 CAD. HIV testing alone (Q3 months) averted 898 of infections with a cost savings of $4,000 CAD per QALY.<h4>Conclusions</h4>The optimal implementation strategy for PrEP over the next 20 years at this urban centre is to target high-risk MSM and to maximize efficacy by supporting PrEP adherence. A large health benefit of PrEP implementation could come from engaging undiagnosed HIV-infected individuals into care.
Project description:HIV pre-exposure prophylaxis (PrEP), the use of antiretroviral drugs by uninfected individuals to prevent HIV infection, has demonstrated effectiveness in preventing acquisition in a high-risk population of men who have sex with men (MSM). Consequently, there is a need to understand if and how PrEP can be used cost-effectively to prevent HIV infection in such populations.We developed a mathematical model representing the HIV epidemic among MSM and transwomen (male-to-female transgender individuals) in Lima, Peru, as a test case. PrEP effectiveness in the model is assumed to result from the combination of a "conditional efficacy" parameter and an adherence parameter. Annual operating costs from a health provider perspective were based on the US Centers for Disease Control and Prevention interim guidelines for PrEP use. The model was used to investigate the population-level impact, cost, and cost-effectiveness of PrEP under a range of implementation scenarios. The epidemiological impact of PrEP is largely driven by programme characteristics. For a modest PrEP coverage of 5%, over 8% of infections could be averted in a programme prioritising those at higher risk and attaining the adherence levels of the Pre-Exposure Prophylaxis Initiative study. Across all scenarios, the highest estimated cost per disability-adjusted life year averted (uniform strategy for a coverage level of 20%, US$1,036-US$4,254) is below the World Health Organization recommended threshold for cost-effective interventions, while only certain optimistic scenarios (low coverage of 5% and some or high prioritisation) are likely to be cost-effective using the World Bank threshold. The impact of PrEP is reduced if those on PrEP decrease condom use, but only extreme behaviour changes among non-adherers (over 80% reduction in condom use) and a low PrEP conditional efficacy (40%) would adversely impact the epidemic. However, PrEP will not arrest HIV transmission in isolation because of its incomplete effectiveness and dependence on adherence, and because the high cost of programmes limits the coverage levels that could potentially be attained.A strategic PrEP intervention could be a cost-effective addition to existing HIV prevention strategies for MSM populations. However, despite being cost-effective, a substantial expenditure would be required to generate significant reductions in incidence. Please see later in the article for the Editors' Summary.
Project description:OBJECTIVES:Preexposure prophylaxis (PrEP) is recommended for preventing HIV infection among individuals at high risk, including men who have sex with men (MSM). Although its individual-level efficacy is proven, questions remain regarding population-level impact of PrEP implementation. DESIGN:We developed an agent-based simulation of HIV transmission among MSM, accounting for demographics, sexual contact network, HIV disease stage, and use of antiretroviral therapy. We use this framework to compare PrEP delivery strategies in terms of impact on HIV incidence and prevalence. RESULTS:The projected reduction in HIV incidence achievable with PrEP reflects both population-level coverage and individual-level adherence (as a proportion of days protected against HIV transmission). For example, provision of PrEP to 40% of HIV-negative MSM reporting more than one sexual partner in the last 12 months, taken with sufficient adherence to provide protection on 40% of days, can reduce HIV incidence by 9.5% (95% uncertainty range: 8%-11%) within 5 years. However, if this could be increased to 80% coverage on 80% of days (eg, through mass campaigns with a long-acting injectable formulation), a 43% (42%-44%) reduction in HIV incidence could be achieved. Delivering PrEP to MSM at high risk for HIV acquisition can augment population-level impact up to 1.8-fold. CONCLUSIONS:If highly ambitious targets for coverage and adherence can be achieved, PrEP can substantially reduce HIV incidence in the short-term. Although the reduction in HIV incidence largely reflects the proportion of person-years protected, the efficiency of PrEP delivery can be enhanced by targeting high-risk populations.
Project description:BACKGROUND:Oral pre-exposure prophylaxis (PrEP) prevents HIV infection in men who have sex with men (MSM); however, adherence is an ongoing concern. Long-acting injectable PrEP is being tested in phase 3 trials and could address challenges associated with adherence. We examined the potential effectiveness of long-acting injectable PrEP compared with oral PrEP in MSM. METHODS:We used an agent-based model to simulate HIV transmission in a dynamic network of 11?245 MSM in Atlanta, GA, USA. We used raw data from studies in macaque models and pharmacokinetic data from safety trials to estimate the time-varying efficacy of long-acting injectable PrEP. The effect of long-acting injectable PrEP on the cumulative number of new HIV infections over 10 years (2015-24) was compared with no PrEP and daily oral PrEP across a range of coverage levels. Sensitivity analyses were done with varying maximum efficacy and drug half-life values. FINDINGS:In the absence of PrEP, the model predicted 2374 new HIV infections (95% simulation interval [SI] 2345-2412) between 2015 and 2024. The cumulative number of new HIV infections was reduced in all scenarios in which MSM received long-acting injectable PrEP compared with oral PrEP. At a coverage level of 35%, compared with no PrEP, long-acting injectable PrEP led to a 44% reduction in new HIV infections (1044 new infections averted [95% SI 1018-1077]) versus 33% (792 infections averted [763-821]) for oral PrEP. The relative benefit of long-acting injectable PrEP was sensitive to the assumed efficacy of injections received every 8 weeks, discontinuation rates, and terminal drug half-life. INTERPRETATION:Long-acting injectable PrEP has the potential to produce larger reductions in HIV transmission in MSM than oral PrEP. However, the real-world, population-level impact of this approach will depend on uptake of this prevention method and its effectiveness, as well as retention of patients in clinical care. FUNDING:National Institute on Drug Abuse and National Institute of Mental Health.
Project description:Safe and effective HIV prevention strategies are needed for transwomen. Transwomen in the US have a 34 times greater odds of being infected with HIV than all adults age 15-49, and in San Francisco, California 42.4% of transwomen are estimated to be infected with HIV. Pre-exposure prophylaxis (PrEP) is the first biomedical intervention with promise for reducing HIV acquisition in transwomen. However, little is known about whether transwomen know about PrEP, are taking PrEP and would be good candidates for PrEP based on their risk profile and behaviors. A population-based dataset was analyzed to determine how many transwomen in San Francisco knew about PrEP by the end of 2013 - more than a year after iPrex results demonstrated efficacy of PrEP in preventing HIV. We found that of 233 transwomen, only 13.7% had heard of PrEP. Transwomen who were living with HIV compared to those who were HIV-negative, and those who recently injected drugs compared to non-injection drug users were more likely to have heard of PrEP. Based on CDC guidelines for PrEP among MSM and IDU, 45 (30.2%) transwomen of the 149 HIV-negative transwomen in the sample were candidates for PrEP. This estimate based on CDC criteria is arguably low. Given that almost half of transwomen in San Francisco are living with HIV, this findings points to a need for further consideration of PrEP criteria that are specific and tailored to the risks for HIV faced by transwomen that are different from MSM and injection drug users. Research to scale up access and test the effectiveness of PrEP for transwomen is also urgently needed.