Integrated strategies for combination HIV prevention: principles and examples for men who have sex with men in the Americas and heterosexual African populations.
ABSTRACT: Combination HIV prevention is of high priority for increasing the impact of partially efficacious HIV prevention interventions for specific populations and settings. Developing the package requires critical review of local epidemiology of HIV infection regarding most-impacted populations and those at high risk of HIV transmission and acquisition, drivers of HIV infection, and available interventions to address these risk factors. Interventions should be considered in terms of the evidence basis for efficacy, potential synergies, and feasibility of delivery at scale, which is important to achieve high coverage and impact, coupled with high acceptability to populations, which will impact uptake, adherence, and retention. Evaluation requires process measures of uptake, adherence, retention, and outcome measures of reduction in HIV infectiousness and acquisition. Three examples of combination prevention concepts are summarized for men who have sex with men in the Americas, young women in sub-Saharan Africa, and HIV serodiscordant couples.
Project description:PURPOSE:Several randomized, controlled trials (RCTs) have tested strategies to prevent sexual acquisition of HIV infection, but their quality has been variable. We aimed to identify, describe, and evaluate the quality of RCTs studying biomedical interventions to prevent HIV acquisition by sexual transmission. METHOD:We conducted a systematic review to identify all RCTs evaluating the efficacy of biomedical HIV prevention interventions. We assessed seven generic and content-specific quality components important in HIV prevention trials, factors influencing study power, co-interventions provided, and trial ethics. RESULTS:We identified 26 eligible RCTs. The median number of quality components judged to be in adequate or unclear was 3 (range 1-4) in 1992-1998, 3 (range 1-4) in 1999-2003, and 0 (range0-2) in 2004-2008 (p < .001). Common problems that may have biased results included low retention (median 84%), poor adherence to interventions requiring on going use (median < or =78%), and lower HIV incidence than expected a priori (in 8 of 11 trials where evaluable). CONCLUSION:Reporting of trials of biomedical HIV prevention interventions has improved over time. However, quality improvement is needed in several key areas that influence study power, including participant retention, adherence to interventions, and estimation of expected HIV incidence.
Project description:BACKGROUND:Based on government estimates from the Asian Epidemic Model, new infections among men who have sex with men (MSM) and transgender women (TGW) in Thailand are forecast to proportionally increase over time. Daily oral Pre-exposure prophylaxis (PrEP) protects against HIV acquisition when used as prescribed. The "Princess PrEP" program is the first key population-led (PrEP) initiative under Thai royal patronage with an aim to scale up countrywide implementation of PrEP. METHODS:Retention in and adherence to key population-led HIV PrEP services among HIV-uninfected Thai MSM and TGW was examined in four provinces: Bangkok, Chonburi, Chiang Mai, and Songkhla. HIV, HBsAg, creatinine tests, and self-administered questionnaires were performed during baseline measures. Participants were followed up after month 1, at month 3, then every 3 months. Correlates of nonadherence and loss to follow up at 1 month were assessed using linear regression models. RESULTS:37.4% of the participants reported low adherence to services (≤ 3 pills/week or missed clinic schedule at month 1). Factors associated with low adherence included younger age (25 years and under) (adjusted odds ratio (aOR): 1.49, 95% confidence interval (95% CI: 1.01-2.21, p = 0.044), being a TGW (aOR: 2.2, 95% CI: 1.27-3.83, p = 0.005), and whether the participant had not previously accessed services at the clinic (aOR = 1.68, 95% CI: 1.03-2.76, p = 0.04). Additionally, participants in Chonburi (the only TGW site) showed significantly lower adherence than those in the other three provinces (aOR: 2.91, 95% CI: 1.55-5.45, p = 0.001). CONCLUSION:Urgent, innovative interventions for early PrEP adherence support among vulnerable sub-populations such as younger users, TGW, and new clients are needed to maximize prevention strategy in Thailand.
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:INTRODUCTION:This review assesses the impact of prevention interventions for people living with HIV on HIV-related mortality, morbidity, retention in care, quality of life, and prevention of ongoing HIV transmission in resource-limited settings (RLSs). METHODS:We conducted a systematic review of studies reporting the results of prevention interventions for people living with HIV in RLS published between January 2000 and August 2014. Standardized methods of searching and data abstraction were used. RESULTS:Ninety-two studies met the eligibility criteria: 24 articles related to adherence counseling and support, 13 on risk reduction education and condom provision, 19 on partner HIV testing and counseling, 14 on provision of family planning services, and 22 on assessment and treatment of other sexually transmitted infections. Findings indicate good evidence that adherence counseling and sexually transmitted infection treatment can have a high impact on morbidity, whereas risk reduction education, partner HIV testing and counseling, and family planning counseling can prevent transmission of HIV. More limited evidence was found to support the impact of these interventions on retention in care and quality of life. Most studies did not report cost information, making it difficult to draw conclusions about the cost-effectiveness of these interventions. CONCLUSIONS:This evidence suggests that these prevention interventions, if brought to sufficient scale and coverage, can help support and optimize the impact of core treatment and prevention interventions in RLS. Further operational research with more rigorous study designs, and ideally with biomarkers and costing information, is needed to determine the best model for providing these interventions in RLS.
Project description:Men who have sex with men (MSM) can reduce their risk of acquiring human immunodeficiency virus (HIV) by using various prevention strategies and by understanding the effectiveness of each option over the short- and long-term. Strategies examined were: circumcision; insertive anal sex only; consistent, 100% self-reported condom use; and pre-exposure prophylaxis (PrEP). PrEP efficacy was based on three levels of adherence. The cumulative HIV acquisition risk among MSM over periods of 1 year and 10 years were estimated with and without single and combinations of prevention strategies. A Bernoulli process model was used to estimate risk. In the base case with no prevention strategies, the 1-year risk of HIV acquisition among MSM was 8.8%. In contrast, the 1-year risk associated with circumcision alone was 6.9%; with insertive sex only, 5.5%; with 100% self-reported condom use, 2.7%; and with average, high, and very high PrEP adherence, 5.1%, 2.5%, and 0.7%, respectively. The 10-year risk of HIV acquisition among MSM with no prevention strategy was 60.3%. In contrast, that associated with circumcision alone was 51.1%; with insertive sex only, 43.1%; with 100% self-reported condom use, 24.0%; and with average, high, and very high PrEP adherence, 40.5%, 22.2%, and 7.2%, respectively. While MSM face substantial risk of HIV, there are now a number of prevention strategies that reduce risk. Very high adherence to PrEP alone or with other strategies appears to be the most powerful tool for HIV prevention.
Project description:Social workers are often on the front lines of the HIV/AIDS epidemic delivering prevention education and interventions, offering or linking individuals to HIV testing, and working to improve treatment access, retention, and adherence, especially among vulnerable populations. Individuals with substance use disorders face additional challenges to reducing sexual and drug risk behaviors, as well as barriers to testing, treatment, and antiretroviral therapy adherence. This article presents current data on HIV transmission and research evidence on prevention and intervention with substance abusers and highlights how individual social workers can take advantage of this knowledge in practice and through adoption and implementation within organizations.
Project description:Abstract Introduction Men who have sex with men (MSM), and transgender women (TGW), face specific obstacles to retention in care, particularly in settings with stigmatization such as sub?Saharan Africa. We evaluated the impacts of HIV status and other factors on loss?to?follow?up (LTFU) and visit adherence among MSM and TGW in Abuja and Lagos, Nigeria. Methods TRUST/RV368 is an open cohort that provides comprehensive and integrated prevention and treatment services for HIV and sexually transmitted infections (STIs) at community venues supportive of sexual and gender minorities. Recruitment began in March 2013 and participants were followed every three months for up to 18 months. LTFU was defined as not presenting for an expected visit in the past 180 days. Visit adherence was calculated as a rate of completed visits adjusted by the number of three?month intervals elapsed since enrolment. HIV and other factors predictive of LTFU and visit adherence were evaluated using Cox proportional hazards and Poisson regression models, respectively. Results A total of 1447 participants who completed enrolment evaluations over two visits as of November 2018 were included in these analyses. Their median age was 24 years (interquartile range [IQR]: 21 to 28) and 53% (n = 766) were living with HIV. LTFU occurred in 56% (n = 808) and visit adherence was 0.62 (95% confidence interval: 0.61 to 0.64) visits per three?month interval. Participants at risk and living with HIV had median follow?up times of 12 months (IQR: 6 to 22), and 21 months (IQR: 12 to 30), respectively (p < 0.01). After controlling for other factors, LTFU was less common among participants living with HIV or other STIs and more common among those who did not own a cell phone, sold sex and had never undergone HIV testing prior to enrolment. These factors had parallel associations with visit adherence. Conclusions Retention was suboptimal in Nigerian clinics designed to serve MSM and TGW. Particularly high LTFU and low visit adherence among participants at risk for HIV could complicate deployment of HIV prevention interventions. Marketing the benefits of testing, improving access to cell phones and nurturing more trust with clients may improve retention among marginalized communities in Nigeria.
Project description:INTRODUCTION:The use of combination HIV prevention interventions (CHPI) now represent the standard of care to minimize HIV acquisition risks among men who have sex with men (MSM). There has been limited evaluation of these approaches in generalized HIV epidemics and/or where MSM are stigmatized. A peer-based CHPI program to target individual, social, and structural risks for HIV was developed for MSM in Blantyre, Malawi. METHODS:To test the feasibility of CHPI, adult MSM were followed prospectively from January 2012 to May 2013. Participants (N = 103) completed sociobehavioral surveys and HIV testing at each of the 3 follow-up study visits. RESULTS:Approximately 90% of participants attended each study visit and 93.2% (n = 96) completed the final visit. Participants met with peer educators a median of 3 times (range: 1-10) in the follow-up visits 2 and 3. Condom use at last sex improved from baseline through follow-up visit 3 with main (baseline: 62.5%, follow-up 3: 77.0%; P = 0.02) and casual male partners (baseline: 70.7%, follow-up 3: 86.3%; P = 0.01). Disclosure of sexual behaviors/orientation to family increased from 25% in follow-up 1 to 55% in follow-up 3 (P < 0.01). DISCUSSION:Participants maintained a high level of retention in the study highlighting the feasibility of leveraging community-based organizations to recruit and retain MSM in HIV prevention and treatment interventions in stigmatizing settings. Group-level changes in sexual behavior and disclosure in safe settings for MSM were noted. CHPI may represent a useful model to providing access to other HIV prevention for MSM and aiding retention in care and treatment services for MSM living with HIV in challenging environments.
Project description:<h4>Background</h4>The human immunodeficiency virus (HIV) epidemic in Newark, New Jersey, is among the most severe in the United States. Prevalence ranges up to 3.3% in some groups. The aim of this study is to use a mathematical model of the epidemic in Newark to assess the impact of interventions along the continuum of care, leading to virologic suppression.<h4>Methods</h4>A model was constructed of HIV infection including specific care-continuum steps. The model was calibrated to HIV/AIDS cases in Newark among different populations over a 10-year period. Interventions applied to model fits were increasing proportions tested, linked and retained in care, linked and adherent to treatment, and increasing testing frequency, high-risk-group testing, and adherence. Impacts were assessed by measuring incidence and death reductions 10 years postintervention.<h4>Results</h4>The most effective interventions for reducing incidence were improving treatment adherence and increasing testing frequency and coverage. No single intervention reduced incidence in 2023 by >5%, and the most effective combination of interventions reduced incidence by approximately 16% (2%-24%). The most efficacious interventions for reducing deaths were increasing retention, linkage to care, testing coverage, and adherence. Increasing retention reduced deaths by approximately 27% (24%-29%); the most efficacious combination of interventions reduced deaths in 2023 by approximately 52% (46%-57%).<h4>Conclusions</h4>Reducing HIV deaths in Newark over a 10-year period may be a realizable goal, but reducing incidence is less likely. Our results highlight the importance of addressing leaks across the entire continuum of care and reinforcing efforts to prevention new HIV infections with additional interventions.
Project description:Efforts to decrease the spread of HIV worldwide continue at a rapid pace. With the development of new biomedical interventions and findings from pivotal clinical trials, a new framework for short-term and long-term prevention strategies is emerging. It is clear that biomedical-based approaches targeted at the highest risk populations have the greatest potential to have a short-term impact. Unfortunately, challenges with adherence in healthy populations at risk are now well-recognized, and competing health care priorities in the context of fragile delivery infrastructures pose formidable obstacles to implementation. We need better ways to identify high-risk populations, sophisticated understanding of the behavioral parameters that can ensure adherence, and the development of better strategies to provide sustained delivery of preexposure prophylaxis (PrEP). In the long term, we need an effective vaccine--a path that has proven to be rocky. Research facilitating an increased understanding of immune responses and what represents effective responses to prevent HIV acquisition should facilitate progress. While we wait for that time, PrEP offers the best strategy for short-term impact.