Mapping the number of female sex workers in countries across sub-Saharan Africa.

Female sex workers (FSW) are affected by individual, network, and structural risks, making them vulnerable to poor health and well-being. HIV prevention strategies and local community-based programs can rely on estimates of the number of FSW to plan and implement differentiated HIV prevention and treatment services. However, there are limited systematic assessments of the number of FSW in countries across sub-Saharan Africa to facilitate the identification of prevention and treatment gaps. Here we provide estimated population sizes of FSW and the corresponding uncertainties for almost all sub-national areas in sub-Saharan Africa. We first performed a literature review of FSW size estimates and then developed a Bayesian hierarchical model to synthesize these size estimates, resolving competing size estimates in the same area and producing estimates in areas without any data. We estimated that there are 2.5 million (95% uncertainty interval 1.9 to 3.1) FSW aged 15 to 49 in sub-Saharan Africa. This represents a proportion as percent of all women of childbearing age of 1.1% (95% uncertainty interval 0.8 to 1.3%). The analyses further revealed substantial differences between the proportions of FSW among adult females at the sub-national level and studied the relationship between these heterogeneities and many predictors. Ultimately, achieving the vision of no new HIV infections by 2030 necessitates dramatic improvements in our delivery of evidence-based services for sex workers across sub-Saharan Africa.

Implementing HIV Prevention in Sub-Saharan Africa: A Systematic Review of Interventions Targeting Systems, Communities, and Individuals.

HIV remains a threat to global public health, disproportionately affecting countries across Sub-Saharan Africa. Although treatment and access to care have improved, prevention remains critical to ending new HIV infections by 2030. A variety of prevention strategies exist, yet their effectiveness is difficult to measure and variable due to the nature of the interventions and vulnerability of the intervention during implementation. This systematic review of 51 studies synthesizes data on the implementation and evaluation of evidence-based HIV prevention interventions across Sub-Saharan Africa. Studies were included if they occurred between January 1, 2008, and December 31, 2019, inclusive in Sub-Saharan Africa, were written in English, implemented an HIV prevention intervention in the field, and had reportable results. Using a modified social-ecological model for HIV prevention, we divided studies into three categories: interventions targeting health systems (n = 16), communities (n = 8), and individuals (n = 27). Across all categories, the data emphasized preventing mother-to-child transmission (PMTCT), medical interventions, and psychosocial interventions. The most successful programs bundled several interventions that were integrated into the health system. There is a notable lack of interventions targeting key populations and there are significant rates of loss to follow up (LTFU) across many studies. This review provides insight into the prioritization of evidence-based HIV prevention interventions across Sub-Saharan Africa.

A Systematic Review of HIV Testing Implementation Strategies in Sub-Saharan African Countries.

HIV/AIDS remains a looming presence in public health across the world, particularly in Sub-Saharan Africa. The HIV Care Cascade hinges on testing and knowledge of HIV status. Though significant advances have been made in diagnosing people living with HIV (PLHIV), limitations in understanding which strategies are best suited to certain regions or populations have contributed to the uneven distribution in the success of various HIV testing strategies. Here, we present a conceptual framework that outlines effective HIV testing strategies for four target groups. This framework is based on a systematic literature review of articles published from January 1st, 2008, to December 31st, 2019. The effectiveness of HIV testing strategies depends on various factors including the setting, type of test and service providers. Multiple strategies are needed to reach the UNAIDS target of 95% of individuals knowing their HIV status. Expansion of community-based approaches, self-testing and HIV testing services in antenatal care will further improve the state of HIV testing in Sub-Saharan Africa.

A Systematic Review of Linkage-to-Care and Antiretroviral Initiation Implementation Strategies in Low- and Middle-Income Countries Across Sub-Saharan Africa.

Linkage to care (LTC) and initiation of antiretroviral therapy (ART) are key components in the longitudinal care cascade for people living with HIV. Many strategies to optimize these stages of HIV care have been implemented, though there is a paucity of analyses comparing the outcomes of these efforts in low- and middle-income countries. We conducted a systematic review of studies assessing interventions along all stages of the HIV care continuum published between 2008 and 2020. A comprehensive search strategy reviewed five electronic databases to capture studies assessing HIV testing, LTC, ART initiation, ART adherence, and viral suppression. Of the 388 articles that met the inclusion criteria, 78 described interventions for improving LTC/ART initiation. Efforts focused on empowering patients through integrative approaches generally yielded more substantive results compared to provider-initiated non-adaptive LTC interventions or cash incentives. Specifically, tailoring care and incorporating ART initiation into existing infrastructures, such as maternal clinics, had a high impact across settings. Moreover, strategies such as home-based HIV counseling and testing (HBHCT) appear to be most effective when implemented in tandem with other approaches including motivational counseling and point-of-care CD4 testing.

Effects of Cholesterol in Stress-Related Neuronal Death-A Statistical Analysis Perspective.

The association between plasma cholesterol levels and the development of dementia continues to be an important topic of discussion in the scientific community, while the results in the literature vary significantly. We study the effect of reducing oxidized neuronal cholesterol on the lipid raft structure of plasma membrane. The levels of plasma membrane cholesterol were reduced by treating the intact cells with methyl-ß-cyclodextrin (MßCD). The relationship between the cell viability with varying levels of MßCD was then examined. The viability curves are well described by a modified form of the empirical Gompertz law of mortality. A detailed statistical analysis is performed on the fitting results, showing that increasing MßCD concentration has a minor, rather than significant, effect on the cellular viability. In particular, the dependence of viability on MßCD concentration was found to be characterized by a ~25% increase per 1 µM of MßCD concentration.

Systematic review of interventions aimed at improving HIV adherence to care in low- and middle-income countries in Sub-Saharan Africa.

Long-term adherence to antiretroviral medication continues to present as a challenge along the continuum of the HIV care cascade. HIV interventions and support programs are significantly threatened in resource-limited settings by challenges in maintaining long-term follow-up for ART adherence. We sought to complete a systematic review to comprehensively examine ART adherence and retention in care interventions in Sub-Saharan Africa and to report on the implementation of interventions in real-world settings to inform future health investments in HIV care. Interventions were grouped according to their impact on individual, community, and health-systems levels. While a vast majority of studies evaluated a combination of interventions, those studies that incorporated the community as a resource were most successful. In addition, providing education and behavior reminders proved effective and should be accompanied by community and peer efforts for best results. Multi-level interventions, such as combining individual and community-level interventions showed promising results for long term ART adherence.

Evaluating the quality of HIV epidemiologic evidence for populations in the absence of a reliable sampling frame: a modified quality assessment tool.

BACKGROUND: Sampling frames rarely exist for key populations at highest risk for HIV, such as sex workers, men who have sex with men, people who use drugs, and transgender populations. Without reliable sampling frames, most data collection relies on non-probability sampling approaches including network-based methods (e.g. respondent driven sampling) and venue-based methods (e.g. time-location sampling). Quality of implementation and reporting of these studies is highly variable, making wide-ranging estimates often difficult to compare. Here, a modified quality assessment tool, Global.HIV Quality Assessment Tool for Data Generated through Non-Probability Sampling (GHQAT), was developed to evaluate the quality of HIV epidemiologic evidence generated using non-probability methods. METHODS: The GHQAT assesses three main domains: study design, study implementation, and indicator-specific criteria(prevalence, incidence, HIV continuum of care, and population size estimates). The study design domain focuses primarily on the specification of the target and study populations. The study implementation domain is concerned with sampling implementation. Each indicator-specific section contains items relevant to that specific indicator. A random subset of 50 studies from a larger systematic review on epidemiologic data related to HIV and key populations was generated and reviewed using the GHQAT by two independent reviewers. Inter-rater reliability was assessed by calculating intraclass correlation coefficients for the scores assigned to study design, study implementation and each of the indicator-specific criteria. Agreement was categorized as poor(0.00-0.50), fair(0.51-0.70), and good(0.71-1.00). The distribution of good, fair, and poor scores for each section was described. RESULTS: Overall, agreement between the two independent reviewers was good(ICC >0.7). Agreement was best for the section evaluating the HIV continuum of care(ICC = 0.96). For HIV incidence, perfect agreement was observed, but this is likely due to the small number of studies reviewed that assessed incidence(n = 3). Of the studies reviewed, 2% (n = 1) received a score of "poor" for study design, while 50% (n = 25) received a score of "poor" for study implementation. CONCLUSIONS: Addressing HIV prevention and treatment needs of key populations is increasingly understood to be central to HIV responses across HIV epidemic settings, though data characterizing specific needs remains highly variable with the least amount of information in the most stigmatizing settings. Here, we present an efficient tool to guide HIV prevention and treatment programs as well as epidemiological data collection by reliably synthesizing the quality of available non-probability based epidemiologic information for key populations. This tool may help shed light on how researchers may improve not only the implementation of, but also the reporting on their studies.

Using factor analyses to estimate the number of female sex workers across Malawi from multiple regional sources.

PURPOSE: Human immunodeficiency virus (HIV) risks are heterogeneous in nature even in generalized epidemics. However, data are often missing for those at highest risk of HIV, including female sex workers. Statistical models may be used to address data gaps where direct, empiric estimates do not exist. METHODS: We proposed a new size estimation method that combines multiple data sources (the Malawi Biological and Behavioral Surveillance Survey, the Priorities for Local AIDS Control Efforts study, and the Malawi Demographic Household Survey). We used factor analysis to extract information from auxiliary variables and constructed a linear mixed effects model for predicting population size for all districts of Malawi. RESULTS: On average, the predicted proportion of female sex workers among women of reproductive age across all districts was about 0.58%. The estimated proportions seemed reasonable in comparing with a recent study Priorities for Local AIDS Control Efforts II (PLACE II). Compared with using a single data source, we observed increased precision and better geographic coverage. CONCLUSIONS: We illustrate how size estimates from different data sources may be combined for prediction. Applying this approach to other subpopulations in Malawi and to countries where size estimate data are lacking can ultimately inform national modeling processes and estimate the distribution of risks and priorities for HIV prevention and treatment programs.

Characterizing the role of intersecting stigmas and sustained inequities in driving HIV syndemics across low-to-middle-income settings.

PURPOSE OF REVIEW: In 2020, key populations around the world still have disproportionate risks for HIV acquisition and experiencing HIV-related syndemics. This review presents current data around HIV-related syndemics among key populations globally, and on the role of intersecting stigmas in producing these syndemics in low-to-middle-income settings. RECENT FINDINGS: Sex workers, sexual and gender minorities, prisoners, and people who use drugs experience high burdens of tuberculosis, sexually transmitted infections, viral hepatitis, and violence linked to heightened HIV-related risks or acquisition. Adverse sexual, reproductive, and mental health outcomes are also common and similarly amplify HIV acquisition and transmission risks, highlighting the need for psychosocial and reproductive health services for key populations. SUMMARY: Achieving the promise of biomedical interventions to support HIV care and prevention requires action towards addressing syndemics of HIV, and the stigmas that reproduce them, among those most marginalized globally.

The uptake of population size estimation studies for key populations in guiding HIV responses on the African continent.

BACKGROUND: There has been a heightened emphasis on prioritizing data to inform evidence-based HIV responses, including data focused on both defining the content and scale of HIV programs in response to evidence-based need. Consequently, population size estimation (PSE) studies for key populations have become increasingly common to define the necessary scale of specific programs for key populations. This study aims to assess the research utilization of these size estimates in informing HIV policy and program documents across the African continent. METHODS: This study included two phases; Phase 1 was a review of all PSE for key populations, including men who have sex with men (MSM), female sex workers (FSW), people who use drugs (PWUD), and transgender persons in the 54 countries across Africa published from January 2009-December 2017. Phase 2 was a review of 23 different types of documents released between January 2009 -January 2019, with a focus on the US President's Emergency Plan for AIDS Relief (PEPFAR) and The Global Fund to Fight AIDS, Tuberculosis and Malaria investments, for evidence of stakeholder engagement in PSE studies, as well as key population PSE research utilization to inform HIV programming and international HIV investments. RESULTS: Of 118 size estimates identified in 39 studies, less than 15% were utilized in PEPFAR Country Operational Plans or national strategic health plan documents, and less than 2% in Global Fund Concept Notes. Of 39 PSE studies, over 50% engaged stakeholders in study implementation and identified target population stakeholders, a third of studies identified policy or program stakeholders, and 15% involved stakeholders in study design. CONCLUSION: The past decade has seen an increase in PSE studies conducted for key populations in more generalized HIV epidemic settings which involve significant investments of finances and human resources. However, there remains limited evidence of sustained uptake of these data to guide the HIV responses. Increasing uptake necessitates effective stakeholder engagement and data-oriented capacity building to optimize research utilization and facilitate data-driven and human rights-affirming HIV responses.

HIV-Related Implementation Research for Key Populations: Designing for Individuals, Evaluating Across Populations, and Integrating Context.

INTRODUCTION: Key populations, including men who have sex with men, transgender people, sex workers, people who inject drugs, and incarcerated populations, experience high burdens of HIV and urgently need effective interventions. Yet the evidence base for implementation research (IR) with key populations remains weak and poses specific challenges to epidemiologic inference. We apply the Consolidated Framework for IR to consider specific challenges and recommendations for IR with key populations. DISCUSSION: Individuals within key populations exist within inner and outer settings-including organizational structures, legal (eg, criminalization), and funding environments-which influence the design, adoption and fidelity of interventions, and the potential sustainability of intervention scale-up. Underlying vulnerabilities and external stressors experienced at the individual level (eg, homelessness, violence) further impact participation and retention in IR. Thus, researchers should account for representation in the research process, beginning with community engagement in IR design and consideration of enumeration/sampling methods for key populations who lack probabilistic sampling frames. Interventions for key populations require substantial adaptation and complexity (eg, individually tailored, multicomponent) to ensure appropriateness; however, there is tension between the need for complexity and challenges to internal validity (fidelity) and external validity (generalizable scale-up). Finally, integrating contextual, sampling, and implementation elements into analytic approaches is critical for effectiveness evaluation. CONCLUSIONS: Translation of efficacious findings at the individual level to effectiveness at the population level requires recognition of risk heterogeneity. Recognizing the nuances of working with key populations is essential to ensure that individuals are represented by design and therefore gains in population health can be achieved.