Programme science: a route to effective coverage and population-level impact for HIV and sexually transmitted infection prevention.

Improvements in context-specific programming are essential to address HIV and other sexually transmitted and blood-borne infection epidemics globally. A programme science approach emphasises the need for context-specific evidence and knowledge, generated on an ongoing basis, to inform timely and appropriate programmatic decisions. We aim to accelerate and improve the use of embedded research, inquiry, and learning to optimise population-level impact of public health programmes and to introduce an effective programme coverage framework as one tool to facilitate this goal. The framework was developed in partnership with public health experts in HIV and sexually transmitted and blood-borne infections through several workshops and meetings. The framework is a practice-based tool that centres on the use of data from iterative cycles of programme-embedded research and learning, as well as routine programme monitoring, to refine the strategy and implementation of a programme. This programme science approach aims to reduce programme coverage gaps, to optimise impact at the population level, and to achieve effective coverage. This framework should facilitate the generation of programme-embedded research and learning agendas to inform resource allocation, optimise population-level impact, and achieve equitable and effective programme coverage.

Adequate funding of comprehensive community-based programs for key populations needed now more than ever to reach and sustain HIV targets.

INTRODUCTION: Globally, over half of the estimated new HIV infections now occur among key populations, including men who have sex with men, sex workers, people who inject drugs, transgender individuals, and people in prisons and other closed settings, and their sexual partners. Reaching epidemic control will, for many countries, increasingly require intensified programming and targeted resource allocation to meet the needs of key populations and their sexual partners. However, insufficient funding, both in terms of overall amounts and the way the funding is spent, contributes to the systematic marginalization of key populations from needed HIV services. DISCUSSION: The Joint United Nations Programme on HIV/AIDS (UNAIDS) has recently highlighted the urgent need to take action to end inequalities, including those faced by key populations, which have only been exacerbated by the COVID-19 pandemic. To address these inequalities and improve health outcomes, key population programs must expand the use of a trusted access platform, scale up differentiated service delivery models tailored to the needs of key populations, rollout structural interventions and ensure service integration. These critical program elements are often considered "extras," not necessities, and consequently costing studies of key population programs systematically underestimate the total and unitary costs of services for key populations. Findings from a recent costing study from the LINKAGES project suggest that adequate funding for these four program elements can yield benefits in program performance. Despite this and other evidence, the lack of data on the true costs of these elements and the costs of failing to provide them prevents sufficient investment in these critical elements. CONCLUSIONS: As nations strive to reach the 2030 UNAIDS goals, donors, governments and implementers should reconsider the true, but often hidden costs in future healthcare dollars and in lives if they fail to invest in the community-based and community-driven key population programs that address structural inequities. Supporting these efforts contributes to closing the remaining gaps in the 95-95-95 goals. The financial and opportunity cost of perpetuating inequities and missing those who must be reached in the last mile of HIV epidemic control must be considered.

A decade and beyond: learnings from HIV programming with underserved and marginalized key populations in Kenya.

INTRODUCTION: Key populations (KP) continue to account for high HIV incidence globally. Still, prioritization of KP in the national HIV prevention response remains insufficient, leading to their suboptimal access to HIV programmes. This commentary aims to share Kenya's challenges and successes in achieving 2020 global HIV targets and scaling up the KP programme in the last decade. DISCUSSION: The KP programme in Kenya has scaled up in the last decade with the inclusion of female sex workers (FSW), men who have sex with men (MSM), people who inject drugs (PWID), transgender people and people in prisons as priority populations in the national HIV response. KP coverage based on official size estimates for FSW is 73%, for MSM is 82%, for PWID through needle syringe programme (NSP) is 71%, and through opioid substitution therapy (OST) is 26% and for transgender people is 5%. The service outcomes for KP have been relatively strong in prevention with high condom use at last paid sex for FSW (92%) and use of sterile equipment among PWID (88%), though condom use at last sex with a non-regular partner among MSM (78%) is still low. The KP programme has not met care continuum targets for all subpopulations with low case findings. The national KP programme led by the Ministry of Health has scaled up the programme through (a) strategic partnerships with KP-led and competent organizations, researchers and donors; (b) development of policy guidance and programme standards; (c) continuous sensitization and advocacy to garner support; (d) development of national reporting systems, among others. However, the programme is still struggling with uncertain size estimates; lack of updated bio-behavioural survey data; inadequate scale-up of interventions among transgender people and people in prison settings; gaps in reaching adolescent and young KP, and effectively addressing structural barriers like violence and stigma. CONCLUSIONS: To reach the ambitious global HIV targets, sufficient coverage of KP with quality HIV programmes is critical. Despite scaling up the KP programme, Kenya has not yet achieved the 2020 global HIV targets and needs more efforts to scale-up quality programmes for KP who are underserved in the HIV response.

Control of sexually transmitted infections and global elimination targets, South-East Asia Region.

The World Health Organization (WHO) set targets for a 90% reduction in the incidence of syphilis and gonorrhoea between 2018 and 2030. We review trends in sexually transmitted infections in the WHO South-East Asia Region to assess the feasibility of reaching these targets. Myanmar, Sri Lanka and Thailand reported 90% or greater reductions in the incidence or prevalence of syphilis and/or gonorrhoea between 1975 and 2005. Evidence suggests that smaller, more recent reductions in trends in sexually transmitted infections in India have driven regional declines. In other countries, sexually transmitted infections remain high or are increasing or data are not reliable enough to measure change. Sri Lanka and Thailand have strong control programmes for sexually transmitted infections that ensure universal access to services for these infections and targeted interventions in key populations. India and Myanmar have implemented targeted control efforts on a large scale. Other countries of the region have prioritized control of human immunodeficiency virus, and limited resources are available for other sexually transmitted infections. At national and subnational levels, data show rapid declines in sexually transmitted infections when targeted promotion of condom use and sexually transmitted infection services are scaled up to reach large numbers of sex workers. In contrast, recent outbreaks of sexually transmitted infections in underserved populations of men who have sex with men have been linked to rising trends in sexually transmitted infections in the region. A renewed and focused response to sexually transmitted infections in the region is needed to meet global elimination targets.

L'Organisation mondiale de la Santé (OMS) a fixé des objectifs pour réduire à 90% l'incidence de la syphilis et de la gonorrhée entre 2018 et 2030. Nous avons étudié les tendances en matière d'infections sexuellement transmissibles dans la Région d'Asie du Sud-Est de l'OMS afin d'évaluer la faisabilité de ces objectifs. Le Myanmar, le Sri Lanka et la Thaïlande ont signalé une diminution de 90% ou plus dans l'incidence ou la prévalence de la syphilis et/ou de la gonorrhée entre 1975 et 2005. Les données semblent indiquer une tendance à la baisse plus récente et moins significative des infections sexuellement transmissibles en Inde, entraînant une décrue régionale. Dans d'autres pays, soit le nombre d'infections sexuellement transmissibles demeure élevé ou continue sa progression, soit les informations disponibles ne sont pas suffisamment fiables pour en mesurer l'évolution. Le Sri Lanka et la Thaïlande ont établi de solides programmes de lutte contre les infections sexuellement transmissibles, permettant d'accéder à des services spécialement conçus pour leur prise en charge et prévoyant une intervention ciblée au sein des populations clés. De leur côté, l'Inde et le Myanmar ont déployé des efforts à grande échelle afin de mener des actions ciblées. D'autres pays de la région ont privilégié la lutte contre le virus de l'immunodéficience humaine; pour les autres infections sexuellement transmissibles, leurs ressources sont limitées. Aux niveaux national et infranational, les données révèlent un rapide déclin des infections sexuellement transmissibles lorsque la promotion ciblée pour encourager l'usage du préservatif et les services dédiés à la prise en charge de telles affections sont renforcés afin de toucher un plus grand nombre de travailleurs du sexe. En revanche, les épidémies d'infections sexuellement transmissibles observées dernièrement au sein de populations défavorisées d'hommes ayant des relations sexuelles avec d'autres hommes ont entraîné une hausse dans la région. Il est donc indispensable d'apporter une réponse remaniée et ciblée face aux infections sexuellement transmissibles dans la région en vue d'atteindre les objectifs mondiaux d'élimination.

La Organización Mundial de la Salud (OMS) fijó como objetivo una reducción del 90% en la incidencia de la sífilis y la gonorrea entre 2018 y 2030. Revisamos las tendencias de las infecciones de transmisión sexual en la Región del Sudeste Asiático de la OMS para evaluar la viabilidad de alcanzar estos objetivos. Myanmar, Sri Lanka y Tailandia informaron de reducciones del 90% o más en la incidencia o prevalencia de sífilis y/o gonorrea entre 1975 y 2005. Los datos sugieren que las reducciones más pequeñas y recientes en las tendencias de las infecciones de transmisión sexual en la India han impulsado los descensos regionales. En otros países, las infecciones de transmisión sexual siguen siendo elevadas o están aumentando, o los datos no son lo suficientemente fiables como para medir el cambio. Sri Lanka y Tailandia tienen sólidos programas de control de las infecciones de transmisión sexual que garantizan el acceso universal a los servicios para estas infecciones e intervenciones específicas en poblaciones clave. India y Myanmar han implementado esfuerzos de control específicos a gran escala. Otros países de la región han dado prioridad a la lucha contra el virus de la inmunodeficiencia humana y disponen de recursos limitados para otras infecciones de transmisión sexual. A nivel nacional y subnacional, los datos muestran un rápido descenso de las infecciones de transmisión sexual cuando se amplía la promoción del uso del preservativo y los servicios para las infecciones de transmisión sexual para llegar a un gran número de profesionales del ámbito sexual. Por el contrario, los recientes brotes de infecciones de transmisión sexual en poblaciones desatendidas de hombres que tienen relaciones sexuales con otros hombres se han relacionado con las tendencias al alza de las infecciones de transmisión sexual en la región. Se necesita una respuesta renovada y centrada en las infecciones de transmisión sexual en la región para alcanzar los objetivos mundiales de eliminación.

A tale of two cascades: promoting a standardized tool for monitoring progress in HIV prevention.

INTRODUCTION: To achieve significant progress in global HIV prevention from 2020 onward, it is essential to ensure that appropriate programmes are being delivered with high quality and sufficient intensity and scale and then taken up by the people who most need and want them in order to have both individual and public health impact. Yet, currently, there is no standard way of assessing this. Available HIV prevention indicators do not provide a logical set of measures that combine to show reduction in HIV incidence and allow for comparison of success (or failure) of HIV prevention programmes and for monitoring progress in meeting global targets. To redress this, attention increasingly has turned to the prospects of devising an HIV prevention cascade, similar to the now-standard HIV treatment cascade; but this has proven to be a controversial enterprise, chiefly due to the complexity of primary prevention. DISCUSSION: We address a number of core issues attendant with devising prevention cascades, including: determining the population of interest and accounting for the variability and fluidity of HIV-related risk within it; the fact that there are multiple HIV prevention methods, and many people are exposed to a package of them, rather than a single method; and choosing the final step (outcome) in the cascade. We propose two unifying models of prevention cascades-one more appropriate for programme managers and monitors and the other for researchers and programme developers-and note their relationship. We also provide some considerations related to cascade data quality and improvement. CONCLUSIONS: The HIV prevention field has been grappling for years with the idea of developing a standardised way to regularly assess progress and to monitor and improve programmes accordingly. The cascade provides the potential to do this, but it is complicated and highly nuanced. We believe the two models proposed here reflect emerging consensus among the range of stakeholders who have been engaging in this discussion and who are dedicated to achieving global HIV prevention goals by ensuring the most appropriate and effective programmes and methods are supported.

Sex Worker Community-led Interventions Interrupt Sexually Transmitted Infection/Human Immunodeficiency Virus Transmission and Improve Human Immunodeficiency Virus Cascade Outcomes: A Program Review from South India.

Ashodaya Samithi, an organization run by and for female, male, and transgender sex workers in Mysore, India, has worked since 2004 to prevent sexually transmitted infection (STI)/human immunodeficiency virus (HIV) transmission and improve HIV cascade outcomes. We reviewed published and programmatic data, including measures of coverage, uptake, utilization and retention, and relate STI/HIV outcomes to evolving phases of community mobilization. Early interventions designed "for" sex workers mapped areas of sex work and reached half the sex workers in Mysore with condoms and STI services. By late 2005, when Ashodaya Samithi registered as a community-based organization, interventions were implemented "with" sex workers as active partners. Microplanning was introduced to enable peer educators to better organize and monitor their outreach work to reach full coverage. By 2008, programs were run "by" sex workers, with active community decision making. Program data show complete coverage of community outreach and greater than 90% clinic attendance for quarterly checkups by 2010. Reported condom use with last occasional client increased from 65% to 90%. Surveys documented halving of HIV and syphilis prevalence between 2004 and 2009, while gonorrhoea declined by 80%. Between 2005 and 2013, clinic checkups tripled, whereas the number of STIs requiring treatment declined by 99%. New HIV infections also declined, and Ashodaya achieved strong cascade outcomes for HIV testing, antiretroviral treatment linkage, and retention. Program performance dropped markedly during several periods of interrupted funding, then rebounded when restored. Ashodaya appear to have achieved rapid STI/HIV control with community-led approaches including microplanning. Available data support near elimination of curable STIs and optimal cascade outcomes.

Community Inclusion in PrEP Demonstration Projects: Lessons for Scaling Up.

Pre-exposure prophylaxis (PrEP) has emerged as a new HIV prevention strategy. A series of demonstration projects were conducted to explore the use of PrEP outside of clinical trial settings. Learning from the failures in community consultation and involvement in early oral tenofovir trials, these PrEP projects attempted to better engage communities and create spaces for community involvement in the planning and roll out of these projects. We briefly describe the community engagement strategies employed by seven Bill & Melinda Gates Foundation-funded PrEP demonstration projects and the lessons these projects offer for community engagement in PrEP implementation.

Economy, migrant labour and sex work: interplay of HIV epidemic drivers in Zimbabwe over three decades.

BACKGROUND: HIV took off rapidly in Zimbabwe during the 1980s. Yet, between 1998 and 2003, as the economy faltered, HIV prevalence declined abruptly and without clear explanation. METHODS: We reviewed epidemiological, behavioural, and economic data over three decades to understand changes in economic conditions, migrant labour and sex work that may account for observed fluctuations in Zimbabwe's HIV epidemic. Potential biases related to changing epidemic paradigms and data sources were examined. RESULTS: Early studies describe rural poverty, male migrant labour and sex work as conditions facilitating HIV/sexually transmitted infection (STI) transmission. By the mid-1990s, as Zimbabwe's epidemic became more generalized, research focus shifted to general population household surveys. Yet, less than half as many men than women were found at home during surveys in the 1990s, increasing to 80% during the years of economic decline. Other studies suggest that male demand for sex work fell abruptly as migrant workers were laid off, picking up again when the economy rebounded after 2009. Numbers of clients reported by sex workers, and their STI rates, followed similar patterns reaching a nadir in the early 2000s. Studies from 2009 describe a return to more active sex work, linked to increasing client demand, as well as a revitalized programme reaching sex workers. CONCLUSION: The importance of the downturn in migrant labour and resultant changes in sex work may be underestimated as drivers of Zimbabwe's rapid HIV incidence and prevalence declines. Household surveys underrepresent populations at the highest risk of HIV/STI acquisition and transmission, and these biases vary with changing economic conditions.

Micro-planning at scale with key populations in Kenya: Optimising peer educator ratios for programme outreach and HIV/STI service utilisation.

Peer education with micro-planning has been integral to scaling up key population (KP) HIV/STI programmes in Kenya since 2013. Micro-planning reinforces community cohesion within peer networks and standardizes programme inputs, processes and targets for outreach, including peer educator (PE) workloads. We assessed programme performance for outreach-in relation to the mean number of KPs for which one PE is responsible (KP:PE ratio)-and effects on HIV/STI service utilisation. Quarterly programmatic monitoring data were analysed from October 2013 to September 2016 from implementing partners working with female sex workers (FSWs) and men who have sex with men (MSM) across the country. All implementing partners are expected to follow national guidelines and receive micro-planning training for PEs with support from a Technical Support Unit for KP programmes. We examined correlations between KP:PE ratios and regular outreach contacts, condom distribution, risk reduction counselling, STI screening, HIV testing and violence reporting by KPs. Kenya conducted population size estimates (PSEs) of KPs in 2012. From 2013 to 2016, KP programmes were scaled up to reach 85% of FSWs (PSE 133,675) and 90% of MSM (PSE 18,460). Overall, mean KP:PE ratios decreased from 147 to 91 for FSWs, and from 79 to 58 for MSM. Lower KP:PE ratios, up to 90:1 for FSW and 60:1 for MSM, were significantly associated with more regular outreach contacts (p<0.001), as well as more frequent risk reduction counselling (p<0.001), STI screening (p<0.001) and HIV testing (p<0.001). Condom distribution and reporting of violence by KPs did not differ significantly between the two groups over all time periods. Micro-planning with adequate KP:PE ratios is an effective approach to scaling up HIV prevention programmes among KPs, resulting in high levels of programme uptake and service utilisation.

Ethical considerations in global HIV phylogenetic research.

Phylogenetic analysis of pathogens is an increasingly powerful way to reduce the spread of epidemics, including HIV. As a result, phylogenetic approaches are becoming embedded in public health and research programmes, as well as outbreak responses, presenting unique ethical, legal, and social issues that are not adequately addressed by existing bioethics literature. We formed a multidisciplinary working group to explore the ethical issues arising from the design of, conduct in, and use of results from HIV phylogenetic studies, and to propose recommendations to minimise the associated risks to both individuals and groups. We identified eight key ethical domains, within which we highlighted factors that make HIV phylogenetic research unique. In this Review, we endeavoured to provide a framework to assist researchers, public health practitioners, and funding institutions to ensure that HIV phylogenetic studies are designed, done, and disseminated in an ethical manner. Our conclusions also have broader relevance for pathogen phylogenetics.

Using a cascade approach to assess condom uptake in female sex workers in India: a review of the Avahan data.

BACKGROUND: The Avahan India AIDS Initiative was implemented to provide HIV prevention services to key populations including female sex workers (FSWs) who carry the burden of India's concentrated HIV epidemic. Established in 2003 and handed over to the Indian government in 2009, the Initiative included peer-led outreach education, condom promotion and distribution and STI treatment. This study aimed to determine if HIV prevention cascades could be generated using routine monitoring and evaluation data from the Avahan program and to assess their value in identifying and responding to program gaps for FSWs. METHODS: Two data sources were used namely the Integrated Behavioural and Biological Assessment reports and the Centralized Management Information System dataset. Indicators selected for the cascades were: FSWs at risk, belief that HIV can be prevented, condom access and consistent condom use with an occasional partner. Six districts were selected and stratified by HIV prevalence at baseline and two cascades were generated per district reflecting changes over time. RESULTS: Consistent condom use with occasional partners in this population increased in all six districts during program implementation, with statistically significant increases in four of the six. No patterns in the cascades were detected according to HIV prevalence either at baseline (2005) or at follow-up (2009). Cascades were able to identify key programmatic bottlenecks at baseline that could assist with focusing program efforts and direct resources at district levels. In some districts the belief that HIV could not be prevented contributed to inconsistent condom use, while in others, low levels of condom access were a more important barrier to consistent condom use. CONCLUSION: This HIV prevention cascade analysis among FSWs in India suggests that cascades could assist in identifying program gaps, focus intervention efforts and monitor their effect. However, cascades cannot replace a detailed understanding of the multiple factors at individual, community and structural levels that lead to consistent condom use in this key population. Careful indicator selection coupled with innovative data collection methods will be required. Pilot projects are proposed to formally evaluate the value of HIV prevention cascades at district level.

Building the evidence base on the HIV programme in India: an integrated approach to document programmatic learnings.

BACKGROUND: The Knowledge Network project was launched in 2010 to build evidence on the HIV epidemic by using the data generated by HIV programme implementing organisations in India. This paper describes the implementation of the programme and the strategies adopted to enhance the capacity of individuals to document and publish HIV prevention programme learnings. Further, it discusses the outcomes of the initiative. METHODS: A multipronged approach was adopted, where a group of experts were brought together to collaborate with programme implementing organisations, review available data, develop research questions and guide peer-reviewed publications. Further, scientific writing courses were conducted to support individuals from HIV programme implementing organisations as well as educational and government organisations (mentees) to build the documentation capacity of individuals leading programme implementation and current and future researchers. The impact and quality of evidence generated was measured by examining the number of papers published, the number of citations, and the number of papers with at least 10 citations. Additionally, course participants' responses to open-ended questions in the anonymous course evaluation questionnaires are presented as verbatim quotes. RESULTS: Overall, 99 papers on HIV programmatic learnings from India were finalised under the programme, of which 95 have been published. In all, 67 papers were co-authored by mentees. Most papers were published in high-impact factor (1 or more) journals and 72% were cited at least once in the literature. The main themes documented include key populations' HIV risk, HIV risk of general population groups, HIV/STI service delivery models and community mobilisation interventions. CONCLUSION: The study demonstrates that an integrated approach, involving partnership, capacity-building and mentorship, can maximise the use of available data and build the evidence base on HIV programmatic learnings. The capacity-building model adopted in the programme can be used to build scientific writing and documentation capacity in other public health programmes that are implemented at scale.

The HIV prevention cascade: integrating theories of epidemiological, behavioural, and social science into programme design and monitoring.

Theories of epidemiology, health behaviour, and social science have changed the understanding of HIV prevention in the past three decades. The HIV prevention cascade is emerging as a new approach to guide the design and monitoring of HIV prevention programmes in a way that integrates these multiple perspectives. This approach recognises that translating the efficacy of direct mechanisms that mediate HIV prevention (including prevention products, procedures, and risk-reduction behaviours) into population-level effects requires interventions that increase coverage. An HIV prevention cascade approach suggests that high coverage can be achieved by targeting three key components: demand-side interventions that improve risk perception and awareness and acceptability of prevention approaches; supply-side interventions that make prevention products and procedures more accessible and available; and adherence interventions that support ongoing adoption of prevention behaviours, including those that do and do not involve prevention products. Programmes need to develop delivery platforms that ensure these interventions reach target populations, to shape the policy environment so that it facilitates implementation at scale with high quality and intensity, and to monitor the programme with indicators along the cascade.

HIV Prevention 2020: a framework for delivery and a call for action.

Although effective programmes are available and several countries have seen substantial declines in new HIV infections, progress in the reduction of adult HIV incidence has been slower than expected worldwide and many countries have not had large decreases in new infections in adults despite large reductions in paediatric infections. Reasons for slow progress include inadequate commitment, investment, focus, scale, and quality of implementation of prevention and treatment interventions. The UNAIDS-Lancet Commission on Defeating AIDS-Advancing Global Health reported that the provision of large-scale, effective HIV prevention programmes has failed and called on stakeholders to "get serious about HIV prevention". An ambitious worldwide target has been set by UNAIDS to reduce new infections below 500 000 by 2020-a 75% reduction from 2010. Models show that such a reduction requires a combination of primary prevention interventions and preventative effects of treatment. Achievement of the target will require more effective delivery of HIV prevention for sufficient coverage in populations at greatest risk of infection ensuring that interventions that have proved effective are made available, barriers to their uptake are overcome, demand is created, and use is consistent and occurs at the right scale with high coverage. This paper discusses how programmatic targets for prevention in a worldwide plan could be used to re-energise the HIV prevention approach. A management framework is proposed outlining global, regional, national, and subnational actions and is summarised in a call for action on HIV prevention for 2020.

Feasible, Efficient and Necessary, without Exception - Working with Sex Workers Interrupts HIV/STI Transmission and Brings Treatment to Many in Need.

BACKGROUND AND OVERVIEW: High rates of partner change in sex work-whether in professional, 'transactional' or other context-disproportionately drive transmission of HIV and other sexually transmitted infections. Several countries in Asia have demonstrated that reducing transmission in sex work can reverse established epidemics among sex workers, their clients and the general population. Experience and emerging research from Africa reaffirms unprotected sex work to be a key driver of sexual transmission in different contexts and regardless of stage or classification of HIV epidemic. This validation of the epidemiology behind sexual transmission carries an urgent imperative to realign prevention resources and scale up effective targeted interventions in sex work settings, and, given declining HIV resources, to do so efficiently. Eighteen articles in this issue highlight the importance and feasibility of such interventions under four themes: 1) epidemiology, data needs and modelling of sex work in generalised epidemics; 2) implementation science addressing practical aspects of intervention scale-up; 3) community mobilisation and 4) the treatment cascade for sex workers living with HIV. CONCLUSION: Decades of empirical evidence, extended by analyses in this collection, argue that protecting sex work is, without exception, feasible and necessary for controlling HIV/STI epidemics. In addition, the disproportionate burden of HIV borne by sex workers calls for facilitated access to ART, care and support. The imperative for Africa is rapid scale-up of targeted prevention and treatment, facilitated by policies and action to improve conditions where sex work takes place. The opportunity is a wealth of accumulated experience working with sex workers in diverse settings, which can be tapped to make up for lost time. Elsewhere, even in countries with strong interventions and services for sex workers, an emerging challenge is to find ways to sustain them in the face of declining global resources.

Scaling-up HIV responses with key populations in West Africa.

BACKGROUND: Despite decades of HIV responses in pockets of West and Central Africa (WCA), the HIV response with key populations remains an understudied area. Recently, there has been a proliferation of studies highlighting epidemiologic and behavioral data that challenge attitudes of complacency among donors and country governments uncomfortable in addressing key populations. METHODS: The articles in this series highlight new studies that provide a better understanding of the epidemiologic and structural burden facing key populations in the WCA region and how to improve responses through more effective targeting. RESULTS: Key populations face pervasive structural barriers including institutional and sexual violence and an intersection of stigma, criminalization, and marginalization as sexual minorities. Despite decades of smaller interventions that have shown the importance of integrated services for key populations, there remains incongruent provision of outreach or testing or family planning pointing to sustained risk. There remains an incongruent resource provision for key populations where they shoulder the burden of HIV and their access to services alone could turn around HIV epidemics within the region. CONCLUSIONS: These proximal and distal determinants must be addressed in regional efforts, led by the community, and resourced for scale, targeting those most at risk for the acquisition and transmission of HIV. This special issue builds the knowledge base for the region focusing on interventions that remove barriers to service access including treatment uptake for those living with HIV. Better analysis and use of data for strategic planning are shown to lead to more effective targeting of prevention, care, and HIV treatment programs with key populations. These articles further demonstrate the immediate need for comprehensive action to address HIV among key populations throughout the WCA region.

Rolling out new biomedical HIV prevention tools: what can be learned from Avahan, the India AIDS initiative?

More than 30 years after HIV was first identified as a disease, with disastrous consequences for many subpopulations in most countries and for entire populations in some African countries, it continues to occupy centre stage among the world's many global health challenges. Prevention still remains the primary long-term focus. New biomedical tools such as pre-exposure propyhlaxis (PrEP) and treatment hold great promise for select groups such as key populations (KPs) who are critical to transmission dynamics, and serodiscordant couples. Programs delivering these new tools will need to layer them over existing services, with potential modifications for increased and sustained engagement between health services and beneficiaries owing to the nature of the interventions. Avahan, an HIV prevention intervention for KPs in six states in India, achieved population-level impact with conventional prevention programming, which, however, required high program-beneficiary engagement. Avahan's implementation strategy included articulating clear service definitions and denominator-based targets; establishing routine data systems with regular, multilevel supervision that allowed for cross-learning across the program; and developing a cadre of frontline workers through KP peer outreach workers who addressed structural issues and provided viable and sustainable mechanisms for sustained interaction between health services and KPs. This basic prevention implementation infrastructure was used to expand clinical services over time. Many of the lessons from programs such as Avahan can be applied to KP programs that are expanding service scope, including PrEP and treatment.

Learning about scale, measurement and community mobilisation: reflections on the implementation of the Avahan HIV/AIDS initiative in India.

Debates have raged in development for decades about the appropriateness of participatory approaches and the degree to which they can be managed, scaled and measured. The Avahan programme confronted these issues over the last 7 years and concludes that it is advantageous to manage scaled community mobilisation processes so that participation evolves and programming on the ground is shaped by what is learnt through implementation. The donor (Bill & Melinda Gates Foundation) and its partners determined a standard set of programme activities that were implemented programme-wide but evolved with input from communities on the ground. Difficulties faced in monitoring and measurement in Avahan may be characteristic of similar efforts to measure community mobilisation in a scaled programme, and ultimately these challenges informed methods that were useful. The approach the programme undertook for learning and changing, the activities it built into the HIV prevention programme, and its logic model and measurement tools, may be relevant in other public health settings seeking to integrate community mobilisation.