The future of HIV prevention

The First 40 Years of AIDS: Promising Programs, Limited Success

HIV-prevention program planning, implementation, and evaluation began in the United States shortly after reports of a mysterious, apparently acquired, immune deficiency syndrome appeared in summer 1981. In San Francisco, New York City, and elsewhere, members of LGBT communities responded by providing accurate information, giving support, and raising money. During the first decade of the AIDS pandemic (1981–1990), social and behavioral scientists contributed by designing theory-based and practical interventions, combining interventions into programs, and measuring impact on behavior change and HIV incidence. In the second decade (1991–2000), federal, state, and local agencies and organizations played a more prominent role in establishing policies and procedures, funding research and programs, and determining the direction of intervention efforts. In the third decade (2001–2010), biomedical interventions were prioritized over behavioral interventions and have dominated attempts in the fourth decade (2011–2020) to integrate biomedical, behavioral, and structural interventions into coherent, efficient, and cost-effective programs to end AIDS.

Evaluating the impact of DREAMS on HIV incidence among young women who sell sex: protocol for a non-randomised study in Zimbabwe

Background

“Determined, Resilient, AIDS-free, Mentored and Safe” (DREAMS) is a package of biomedical, social and economic interventions offered to adolescent girls and young women aged 10–24 years with the aim of reducing HIV incidence. In four of the six DREAMS districts in Zimbabwe, DREAMS includes an offer of oral pre-exposure prophylaxis (DREAMS+PrEP), alongside interventions to support demand and adherence, to women aged 18–24 who are at highest risk of HIV infection, including young women who sell sex (YWSS). This evaluation study addresses the question: does the delivery of DREAMS+PrEP through various providers reduce HIV incidence among YWSS Zimbabwe? We describe our approach to designing a rigorous study to assess whether DREAMS+PrEP had an impact on HIV incidence.

Methods

The study design needed to account for the fact that: 1) DREAMS+PrEP was non-randomly allocated; 2) there is no sampling frame for the target population for the evaluation; 3) there are a small number of DREAMS districts (N = 6), and 4) DREAMS+PrEP is being implemented by various providers. The study will use a cohort analysis approach to compare HIV incidence among YWSS in two DREAMS+PrEP districts to HIV incidence among YWSS in non-DREAMS comparison sites. YWSS will be referred to services and recruited into the cohort through a network-based (respondent-driven) recruitment strategy, and followed-up 12- and 24-months after enrolment. Women will be asked to complete a questionnaire and offered HIV testing. Additional complications of this study include identifying comparable populations of YWSS in the DREAMS+PrEP and non-DREAMS comparison sites, and retention of YWSS over the 24-month period. The primary outcome is HIV incidence among YWSS HIV-negative at study enrolment measured by repeat, rapid HIV testing over 24-months. Inference will be based on plausibility that DREAMS+PrEP had an impact on HIV incidence. A process evaluation will be conducted to understand intervention implementation, and document any contextual factors determining the success or failure of intervention delivery.

Discussion

HIV prevention products of known efficacy are available. Innovative studies are needed to provide evidence of how to optimise product use through combination interventions to achieve population impact within different contexts. We describe the design of such a study.

Advancing the strategic use of HIV operations research to strengthen local policies and programmes: the Research to Prevention Project

In the field of HIV prevention, there is renewed interest in operations research (OR) within an implementation science framework. The ultimate goal of such studies is to generate new knowledge that can inform local programmes and policies, thus improving access, quality, efficiency and effectiveness. Using four case studies from the USAID-funded Research to Prevention (R2P) project, we highlight the strategic use of OR and the impact it can have on shaping the focus and content of HIV prevention programming across geographic and epidemic settings and populations. These case studies, which include experiences from several sub-Saharan African countries and the Caribbean, emphasize four unique ways that R2P projects utilized OR to stimulate change in a given context, including: (1) translating findings from clinical trials to real-world settings; (2) adapting promising structural interventions to a new context; (3) tailoring effective interventions to underserved populations; and (4) prioritizing key populations within a national response to HIV. Carefully crafted OR can bridge the common gap that exists between research-generated knowledge and field-based practice, lead to substantial, real-world changes in national policies and programmes, and strengthen local organizations and the use of data to be more responsive to a given topic or population, ultimately supporting a locally tailored HIV response.

Enhancing awareness to mitigate the risk of HIV/AIDS in older adults

HIV is often assumed to only affect younger people, and many older people do not realize that they might risk acquiring the virus. Given that sexual transmission is by far the most common way to contract HIV around the world, health care professionals do not usually pay enough attention to the possibility of HIV/AIDS in older adults, based on the common conviction that they no longer have any sexual desires and that they are sexually inactive. Nevertheless, the sexual behavior of older people is likely to change over time, as aging baby boomers progress into their 60s and 70s, meeting the criteria for "successful aging", and not conforming to the stereotype of "sexless elderly". Hence the urgent need to awareness is that HIV remains as a major health threat even in advanced age. Prompt diagnosis and treatment are especially crucial in older adults because of their general frailty and high comorbidity levels. This article reviews recent literature concerning HIV/AIDS in older adults, as regard the related epidemiological, clinical and public health issues, with a view to suggesting how the rising rate of HIV transmission in this age group might be mitigated, and shows the main points that HCP should tackle to identify older people at risk of HIV infection. In summary, there is a pressing need to develop effective prevention schemes and to adapt clinical and programmatic approaches to improve the survival of older people with HIV.

Implementation of adolescent-friendly voluntary medical male circumcision using a school based recruitment program in rural KwaZulu-Natal, South Africa

BACKGROUND

Epidemiological data from South Africa demonstrate that risk of human immunodeficiency virus (HIV) infection in males increases dramatically after adolescence. Targeting adolescent HIV-negative males may be an efficient and cost-effective means of maximising the established HIV prevention benefits of voluntary medical male circumcision (VMMC) in high HIV prevalence-, low circumcision practice-settings. This study assessed the feasibility of recruiting male high school students for VMMC in such a setting in rural KwaZulu-Natal.

METHODS AND FINDINGS

Following community and key stakeholder consultations on the acceptability of VMMC recruitment through schools, information and awareness raising sessions were held in 42 high schools in Vulindlela. A three-phase VMMC demand-creation strategy was implemented in partnership with a local non-governmental organization, ZimnadiZonke, that involved: (i) community consultation and engagement; (ii) in-school VMMC awareness sessions and centralized HIV counselling and testing (HCT) service access; and (iii) peer recruitment and decentralized HCT service access. Transport was provided for volunteers to the Centre for the AIDS Programme of Research in South Africa (CAPRISA) clinic where the forceps-guided VMMC procedure was performed on consenting HIV-negative males. HIV infected volunteers were referred to further care either at the CAPRISA clinic or at public sector clinics. Between March 2011 and February 2013, a total of 5165 circumcisions were performed, the majority (71%) in males aged between 15 and 19 years. Demand-creation strategies were associated with an over five-fold increase in VMMC uptake from an average of 58 procedures/month in initial community engagement phases, to an average of 308 procedures/month on initiation of the peer recruitment-decentralized service phase. Post-operative adverse events were rare (1.2%), mostly minor and self-resolving.

CONCLUSIONS

Optimizing a high volume, adolescent-targeted VMMC program was feasible, acceptable and safe in this setting. Adaptive demand-creation strategies are required to sustain high uptake.

Epidemic impacts of a community empowerment intervention for HIV prevention among female sex workers in generalized and concentrated epidemics

Introduction

Sex workers have endured a high burden of HIV infection in and across HIV epidemics. A comprehensive, community empowerment-based HIV prevention intervention emphasizes sex worker organization and mobilization to address HIV risk and often includes community-led peer education, condom distribution, and other activities. Meta-analysis of such interventions suggests a potential 51% reduction in inconsistent condom use. Mathematical modeling exercises provide theoretical insight into potential impacts of the intervention on HIV incidence and burden in settings where interventions have not yet been implemented.

Methods

We used a deterministic model, Goals, to project the impact on HIV infections when the community empowerment interventions were scaled up among female sex workers in Kenya, Thailand, Brazil, and Ukraine. Modeling scenarios included expansion of the comprehensive community empowerment-based HIV prevention intervention from baseline coverage over a 5-year period (5–65% in Kenya and Ukraine; 10–70% in Thailand and Brazil), while other interventions were held at baseline levels. A second exercise increased the intervention coverage simultaneously with equitable access to ART for sex workers. Impacts on HIV outcomes among sex workers and adults are observed from 2012–2016 and, compared to status quo when all interventions are held constant.

Results

Optimistic but feasible coverage (65%–70%) of the intervention demonstrated a range of impacts on HIV: 220 infections averted over 5 yrs. among sex workers in Thailand, 1,830 in Brazil, 2,220 in Ukraine, and 10,800 infections in Kenya. Impacts of the intervention for female sex workers extend to the adult population, cumulatively averting 730 infections in Thailand to 20,700 adult infections in Kenya. Impacts vary by country, influenced by HIV prevalence in risk groups, risk behaviors, intervention use, and population size.

Discussion

A community empowerment approach to HIV prevention and access to universal ART for female sex workers is a promising human rights-based solution to overcoming the persistent burden of HIV among female sex workers across epidemic settings.

Can treatment-based HIV prevention curb the epidemic among gay and other men who have sex with men? A narrative synthesis of increasing evidence for moderating and countervailing effects

As HIV epidemics among gay and other men who have sex with men (GMSM) persist worldwide, the importance of novel prevention approaches is recognised. Evidence that antiretroviral therapy (ART) can decrease the likelihood of infection is informing emerging HIV prevention approaches, encompassing early initiation of treatment as prevention by people living with HIV and use of antiretroviral drugs as pre-exposure prophylaxis for people presumed to be uninfected. Despite widespread excitement, robust evidence of the beneficial effects of ART-based HIV prevention for GMSM remains limited. Also, theoretical models project widely varying effects of ART-based prevention on the future course of HIV epidemics among GMSM, drawing attention to the possible moderating role of differences in the achievements of local HIV responses and the critical importance of sustained protective sexual practices into the future. Ecological analyses and simulations of ongoing epidemics in major gay communities illustrate that the preventive effects of ART in many settings are being offset by increased sexual risk-taking, as reflected in stable or increasing HIV infection rates. Also, the effects of scaling up HIV testing and treatment among GMSM in settings that are often considered prime examples of the success of ART-based prevention may be levelling as ‘scope for improvement’ diminishes. ART-based approaches further extend the HIV prevention toolkit and substantially increase people’s options to protect themselves and others. The future impact of ART-based prevention on HIV epidemics among GMSM ultimately depends on whether heralded responses offset, attenuate or compound the ongoing social and behavioural changes that drive increased sexual risk.

Combination prevention: new hope for stopping the epidemic

HIV research has identified approaches that can be combined to be more effective in transmission reduction than any 1 modality alone: delayed adolescent sexual debut, mutual monogamy or sexual partner reduction, correct and consistent condom use, pre-exposure prophylaxis with oral antiretroviral drugs or vaginal microbicides, voluntary medical male circumcision, antiretroviral therapy (ART) for prevention (including prevention of mother to child HIV transmission [PMTCT]), treatment of sexually transmitted infections, use of clean needles for all injections, blood screening prior to donation, a future HIV prime/boost vaccine, and the female condom. The extent to which evidence-based modalities can be combined to prevent substantial HIV transmission is largely unknown, but combination approaches that are truly implementable in field conditions are likely to be far more effective than single interventions alone. Analogous to PMTCT, "treatment as prevention" for adult-to-adult transmission reduction includes expanded HIV testing, linkage to care, antiretroviral coverage, retention in care, adherence to therapy, and management of key co-morbidities such as depression and substance use. With successful viral suppression, persons with HIV are far less infectious to others, as we see in the fields of sexually transmitted infection control and mycobacterial disease control (tuberculosis and leprosy). Combination approaches are complex, may involve high program costs, and require substantial global commitments. We present a rationale for such investments and cite an ongoing research agenda that seeks to determine how feasible and cost-effective a combination prevention approach would be in a variety of epidemic contexts, notably that in a sub-Saharan Africa.

Extra-couple HIV transmission in sub-Saharan Africa: a mathematical modelling study of survey data

BACKGROUND

The proportion of heterosexual HIV transmission in sub-Saharan Africa that occurs within cohabiting partnerships, compared with that in single people or extra-couple relationships, is widely debated. We estimated the proportional contribution of different routes of transmission to new HIV infections. As plans to use antiretroviral drugs as a strategy for population-level prevention progress, understanding the importance of different transmission routes is crucial to target intervention efforts.

METHODS

We built a mechanistic model of HIV transmission with data from Demographic and Health Surveys (DHS) for 2003-2011, of 27,201 cohabiting couples (men aged 15-59 years and women aged 15-49 years) from 18 sub-Saharan African countries with information about relationship duration, age at sexual debut, and HIV serostatus. We combined this model with estimates of HIV survival times and country-specific estimates of HIV prevalence and coverage of antiretroviral therapy (ART). We then estimated the proportion of recorded infections in surveyed cohabiting couples that occurred before couple formation, between couple members, and because of extra-couple intercourse.

FINDINGS

In surveyed couples, we estimated that extra-couple transmission accounted for 27-61% of all HIV infections in men and 21-51% of all those in women, with ranges showing intercountry variation. We estimated that in 2011, extra-couple transmission accounted for 32-65% of new incident HIV infections in men in cohabiting couples, and 10-47% of new infections in women in such couples. Our findings suggest that transmission within couples occurs largely from men to women; however, the latter sex have a very high-risk period before couple formation.

INTERPRETATION

Because of the large contribution of extra-couple transmission to new HIV infections, interventions for HIV prevention should target the general sexually active population and not only serodiscordant couples.

FUNDING

US National Institutes of Health, US National Science Foundation, and J S McDonnell Foundation.

Helping clinicians deliver consistent HIV prevention counseling to their HIV-infected patients

The delivery of HIV risk assessment and behavioral counseling by clinicians in HIV clinical settings is one component in a comprehensive "positive prevention" strategy to help patients reduce their transmission risk behavior. Clinicians engage in behavioral prevention inconsistently, however, depending on whether patients are new to a practice or are established in regular care and on their attitudes and characteristics of their practices. We analyzed clinician reports of behavioral prevention delivered before and after participation in a large federal demonstration project of positive prevention interventions. The interventions that were part of this project were successful in increasing behavioral prevention among both new and returning patients. Prior to study interventions, clinicians reported counseling 69% of new patients and 52% of returning patients. In follow-up interviews 12 months after receiving training, clinicians reported delivering prevention messages to 5% more new patients and 9% of returning patients (both p<0.01). After 12 months, clinicians were more likely to engage in behavioral prevention if other providers in their sites were also involved. Clinicians agreeing that behavioral prevention was part of the clinic's mission were more likely to conduct it. The interventions were successful in mitigating the influence of provider attitudes precluding prevention delivery. Intervention strategies can help clinicians more consistently deliver behavioral prevention messages to their HIV-infected patients.