Modeling to Inform the Delivery of HIV Pre-exposure Prophylaxis in Sub-Saharan Africa PDF Download

Author: David Allen Roberts
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Daily oral tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) as HIV pre-exposure prophylaxis (PrEP) is a safe and effective method for HIV prevention and offers potential to substantially reduce HIV incidence in sub-Saharan Africa. Mathematical models are commonly used to project the cost-effectiveness of investments in PrEP in comparison to alternative resource allocation strategies. Predictive modeling can also identify individuals at elevated risk who may benefit most from PrEP. The studies contained in this dissertation address fundamental issues in estimating the cost and potential impact of PrEP implementation in sub-Saharan Africa. First, we estimated the cost of routine PrEP delivery through maternal and child health (MCH) and family planning (FP) clinics in western Kenya (Chapter 1). PrEP delivery through MCH and FP leverages existing service delivery platforms that reach a large fraction of women at elevated HIV risk. Using data from over 20,000 PrEP encounters through 16 clinics, we estimated that the cost per client-month of PrEP dispensed to be $26.52 (2017 USD), with personnel (43%), drugs (25%), and laboratory testing (14%) accounting for the majority of costs. Postponing creatinine testing from PrEP initiation to the first follow-up visit could save 8% of total program costs. Under Ministry of Health implementation, we projected costs would decrease by 38%, but estimates were sensitive to changes in PrEP uptake and retention. Second, we used an individual-based transmission model calibrated to Eswatini to evaluate the sensitivity of model projections of PrEP impact and efficiency to specification HIV exposure heterogeneity (Chapter 2). A common method for introducing HIV exposure heterogeneity into a model is to stratify the population into “risk group” categories with different average sexual behavior parameters, allowing PrEP coverage to vary by risk group without having to explicitly represent individual partnerships. We found that this specification leads to a sharp tradeoff between total impact and efficiency depending on PrEP coverage levels in each risk group. In comparison, PrEP use among the general population is projected to be two times more efficient if PrEP use is prioritized during partnerships and over six times more efficient if use is further prioritized among individuals with HIV-positive partners. In addition, large incidence reductions can be achieved at low levels of PrEP coverage if PrEP use in the general population is concentrated when HIV exposure is more likely, but high levels of PrEP coverage are needed if time-varying individual risk is ignored. Third, we developed and validated HIV risk prediction models incorporating individual-level and geospatial covariates using data from nearly 20,000 individuals in a population-based cohort in rural KwaZulu-Natal, South Africa (Chapter 3). Individual-level predictors included demographic, socioeconomic, and sexual behavior measures, while geospatial covariates included local estimates of community HIV prevalence and viral load. We compared full models to simpler models restricted to only individual-level covariates or only age and geospatial covariates. Models using only age group and geospatial covariates had similar performance (women: area under the receiver operating characteristic curve (AUROC) = 0.65, men: AUROC = 0.71) to the full models (women: AUROC = 0.68, men: AUROC = 0.72). In addition, geospatial models more accurately identified high incidence regions than individual-level models; the 20% of the study area with the highest predicted risk accounted for 60% of the high incidence areas when using geospatial models but only 13% using models with only individual-level covariates. These findings have implications for PrEP policies. Our primary costing study identified service delivery bottlenecks and cost drivers that can inform efforts to streamline PrEP delivery. By ignoring the alignment of PrEP use with time-varying individual HIV exposure, models using a risk group specification may overestimate the cost and underestimate the impact of widespread PrEP availability. Finally, local estimates of HIV prevalence can help identify individuals and areas to prioritize for PrEP services to maximize impact.

Author: Jillian Pintye
Publisher:
ISBN:
Category :
Languages : en
Pages : 94

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Women in sub-Saharan Africa have substantial risk of acquiring HIV acquisition during and soon after pregnancy. Additionally, acute HIV infection among pregnant and breastfeeding women poses a double burden in that acute maternal HIV accounts for nearly one-third of all mother-to-child transmissions of HIV (MTCT). To reach global targets for elimination of MTCT and HIV prevention for mothers, it is critical to integrate effective primary HIV prevention strategies into maternal and child health (MCH) services. Tenofovir disoproxil fumarate (TDF)-based pre-exposure prophylaxis (PrEP) prevents HIV infection in adherent women. The World Health Organization (WHO) recommends PrEP for all individuals, including pregnant and breastfeeding women, at substantial HIV risk (defined as HIV residence in regions where HIV incidence is >3%). Programmatic delivery of PrEP for pregnant women is currently being considered in high-prevalence regions, though implementation approaches that efficiently optimize the benefit of PrEP during pregnancy have not been defined. Additionally, although WHO guidelines support PrEP use in pregnancy, national committees have differed in their conclusions. For example, PrEP use during pregnancy is supported by Kenyan antiretroviral guidelines but the lack of complete safety data led PrEP to be contraindicated for pregnant women in the current South African PrEP guidelines. As countries expand programmatic delivery of PrEP to pregnant women, it is important to understand motivations and beliefs for using PrEP during pregnancy to address concerns unique to this population. The studies within this dissertation address the implementation science gaps described above for the delivery of PrEP for HIV prevention to pregnant and postpartum in sub-Saharan Africa. To inform efficient PrEP delivery models, we present an empiric risk score for identifying pregnant and postpartum Kenyan women at highest risk for HIV acquisition who would mostly benefit from PrEP while reducing unnecessary exposure among low-risk women. Using data that could be easily collected in standard MCH clinic settings without additional laboratory diagnostics, our risk score identified 56% of pregnant women who acquired HIV among just 16% of women. Using register data from 62 antenatal MCH facilities throughout Kenya, we further estimated the absolute number and proportion of HIV-uninfected pregnant women in Kenya who could be offered PrEP under different public health approaches, including offering PrEP universally or based on either regional HIV prevalence and/or individual-level HIV risk factors. We found that offering PrEP only to pregnant women in the region with highest HIV prevalence (Nyanza) would reduce PrEP use among low-risk women by 74%, but exclude 63% of women with high risk for HIV based on individual-level characteristics nationally. To complement service delivery data, we also assessed experiences of using PrEP during pregnancy among HIV-uninfected Kenyan women in HIV-serodiscordant couples who became pregnant while using PrEP. The personal experiences of women with direct exposure to PrEP during pregnancy offers valuable insights for informing development of effective PrEP messaging strategies and programs. Finally, we evaluate whether adverse perinatal outcomes were more frequent in a cohort of Kenyan and Ugandan HIV-infected women who used TDF-containing antiretroviral therapy (ART) during pregnancy compared to HIV-infected women who used ART during pregnancy that did not contain TDF. Our findings support the growing evidence that prolonged prenatal TDF use is not associated with adverse perinatal outcomes and contribute to the few prospective studies evaluating the safety of TDF use during pregnancy from African cohorts. The studies within this dissertation aim to address these implementation science gaps and inform optimal and effective delivery of PrEP for HIV prevention to pregnant and postpartum in sub-Saharan Africa.

Author: Jennifer Velloza
Publisher:
ISBN:
Category :
Languages : en
Pages : 140

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Daily, oral pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) is a highly efficacious HIV prevention strategy for key populations at high risk of HIV, including women, in sub-Saharan Africa. However, open-label studies and demonstration projects have reported that young women have difficulty adhering to PrEP over time, which limits its effectiveness as a prevention option. PrEP projects are now exploring modifiable barriers to adherence among women to maximize its public health benefit as it is being rapidly rolled out worldwide. Mental health factors, including depression, traumatic stress symptoms, and stigma, are highly prevalent among women at high risk of HIV acquisition and are barriers to medication use and health promotion behaviors. However, there has been little consideration until now of how such factors might also influence PrEP adherence among women in sub-Saharan Africa. The aims in this dissertation attempt to fill this research gap by: 1) exploring the impact of depressive symptoms on PrEP adherence among women; 2) examining the mechanisms by which depressive symptoms influence PrEP adherence; 3) describing the broader context of HIV-related stigma and empowerment on PrEP use; and 4) integrating depression screening into HIV care delivery to improve mental health and HIV outcomes. Two studies have examined the influence of depression on PrEP adherence and found that depressive symptoms have a negative effect on daily PrEP use for transgender women and men who have sex with men. Ours is the first study to examine links between depression and PrEP adherence among cisgender women in sub-Saharan Africa. We used marginal structural models to estimate the association between depressive symptoms and PrEP adherence while adjusting for time-varying confounding by sexual behavior, stigma, and social support. We found that probable depression was significantly associated with poor PrEP adherence among women, but not men, suggesting that mental health and depression experiences have differential impact on HIV prevention behaviors by gender. This work also led to questions about the mechanism of this association and whether there were important mediators of the relationship between depression and PrEP adherence that could explain at least some of this total effect. We conducted a mediation analysis using marginal structural models to estimate the controlled direct effect of depression on PrEP adherence, after accounting for the potentially mediating influence of HIV-related stigma, social support, and optimism about PrEP effectiveness. We found a significant negative direct influence of depression on PrEP adherence but this relationship was not strongly mediated by other psychosocial factors. Future research is needed to explore additional potential mediators of this relationship and identify areas for intervention. Qualitative research methods allow us to explore narratives around PrEP use, experiences of stigma, and concerns about mental health that are not captured by quantitative data. We analyzed serial in-depth interview data from a cohort of young women using PrEP to understand the broader context around their pill-taking, mental health, and relationships. In this study, we found that women described experiences of HIV-related stigma when they began taking PrEP which influenced their ability to take PrEP and their feelings about themselves. However, over time, women became more empowered to use PrEP and combat HIV-related stigma by becoming "ambassadors" of PrEP in their communities. This work highlights the potential for empowerment-based interventions to improve PrEP adherence and reduce community stigma and the richness of serially collected qualitative data. In Aims 1-3, we found evidence of a strong negative impact of depression on PrEP adherence and high rates of depression among women at risk of HIV. This work suggests that integrated depression screening and treatment with HIV prevention service delivery could improve mental health outcomes and PrEP effectiveness for women. To support the design of future integrated interventions, we conducted cognitive interviews assessing comprehensibility and acceptability of a widely used depression screening tool in the context of a PrEP delivery intervention among pregnant and postpartum women in Thika, Kenya. We found that the tool was largely acceptable and well-understood, but several minor changes to item wording and instructions would improve symptom screening and linkage to mental health care. These changes are part of our recommendations for the future use of this tool. The collective results presented in this dissertation illustrate the negative influence of depression and related psychosocial factors on consistent PrEP use for women, opportunities for stigma-reduction and empowerment-based intervention approaches to improve mental health symptoms and PrEP use in this population, and the potential to administer depression screening within the context of HIV prevention service delivery. This work contributes to a better understanding of the links between mental health and HIV risk for women and highlights the importance of integrating mental health and empowerment-based interventions with PrEP delivery to improve mental health screening and treatment and PrEP effectiveness for women in sub-Saharan Africa.

Author: King K. Holmes
Publisher: World Bank Publications
ISBN: 1464805253
Category : Medical
Languages : en
Pages : 1027

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Infectious diseases are the leading cause of death globally, particularly among children and young adults. The spread of new pathogens and the threat of antimicrobial resistance pose particular challenges in combating these diseases. Major Infectious Diseases identifies feasible, cost-effective packages of interventions and strategies across delivery platforms to prevent and treat HIV/AIDS, other sexually transmitted infections, tuberculosis, malaria, adult febrile illness, viral hepatitis, and neglected tropical diseases. The volume emphasizes the need to effectively address emerging antimicrobial resistance, strengthen health systems, and increase access to care. The attainable goals are to reduce incidence, develop innovative approaches, and optimize existing tools in resource-constrained settings.

Author:
Publisher: World Health Organization
ISBN: 9240053697
Category : Medical
Languages : en
Pages : 46

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Author: Stephanie Roche
Publisher:
ISBN:
Category :
Languages : en
Pages : 105

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In Kenya, daily oral pre-exposure prophylaxis (PrEP) for HIV prevention is a key component of the country’s national HIV/AIDS response. Since its approval by the Kenya national drug regulatory authority in 2015, PrEP has been rolled out predominantly in HIV clinics; however, the country’s 5-year plan for implementing PrEP at scale calls for integration of PrEP into other service delivery models and more efficient use of available resources. Currently, there is limited implementation science research to inform PrEP scale-up (i.e., expansion to additional HIV clinics) and scale-out (i.e., expansion to new service delivery models and populations) in Kenya. Our objective was to identify barriers and facilitators of PrEP integration and/or optimization in three healthcare settings: HIV clinics, family planning (FP) clinics, and retail pharmacies. In Aim 1, we analyzed data from a prospective cohort study delivering integrated PrEP-FP services to adolescent girls and young women (AGYW) at two FP clinics in Kisumu, Kenya. Using the Consolidated Framework for Implementation Research (CFIR) and the Expert Recommendations for Implementing Change (ERIC) compilation, we identified supply-side implementation strategies for integrating PrEP into routine FP services and contextual factors influencing strategy choice and outcome, as captured in routine monitoring and evaluation documents (n=213) and key informant interviews (n=15). We found that, overall, implementing PrEP was more labor intensive at a public FP clinic compared to a private, youth-friendly clinic because it required a series of implementation strategies to make the physical and social environment conductive to offering AGYW-centered care. Nevertheless, provider adoption of PrEP delivery was low at both clinics, likely due to the widespread perception that PrEP was not within their scope of work. We recommend that PrEP implementers approach PrEP implementation, in part, as a behavioral intervention for FP providers and specifically assess the need for implementation strategies that support providers’ clinical decision-making, address workload constraints, and establish clear worker expectations. In Aim 2, we conducted a pilot study of a one-stop shop (OSS) model for PrEP delivery at four public clinics in Western Province, Kenya and evaluated whether this model could improve care efficiency and acceptability without negatively impacting PrEP uptake or continuation. Interviews with clients (n=15) and providers (n=14), technical assistance reports (n=69), and clinic flow maps indicate that the OSS achieved efficiency gains by redirecting PrEP clients away from bottlenecks, moving steps closer together (e.g., relocating supplies; cross-training and task-shifting), and differentiating clients based on the subset of services needed. Analysis of time-and-motion observations (n=47) revealed that, following OSS implementation, median client wait time dropped significantly from 31 minutes to 6 minutes (p=0.02) while median time spent with a provider remained around 23 minutes (p=0.4). Clients and providers expressed a strong preference for the OSS model and additionally identified increased privacy, reduced stigma, and higher quality client-provider interactions as benefits of the OSS model. Controlled interrupted time series analysis of PrEP initiations (n=1227) and follow-up visits (n=2696) revealed no significant difference between intervention and control clinics in terms of trends in PrEP initiation and on-time returns (all p>0.05). We conclude that the OSS model is a promising option for reducing variability in service time and increasing client and provider satisfaction without adding additional human resources. In Aim 3, we conducted a formative research study to understand the acceptability and feasibility of retail pharmacy-based PrEP delivery. Using the CFIR, we conducted and analyzed in-depth interviews with 40 pharmacy clients, 16 pharmacy providers, 16 PrEP clients, and 10 PrEP providers from Kisumu and Kiambu Counties, Kenya. Most participants expressed strong support for expanding PrEP to retail pharmacies, though conditioned their acceptance on assurances that care would be private, respectful, safe, and affordable. Participant-reported determinants of feasibility centered primarily on ensuring that the intervention is compatible with retail pharmacy operations (e.g., adequate staffing; use of documentation systems that meet PrEP reporting requirements). Our findings may inform the development of a tailored package of implementation strategies for integrating PrEP into routine pharmacy practice.

Author: H. Grant
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Valentine Adhiambo Wanga
Publisher:
ISBN:
Category :
Languages : en
Pages : 82

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The rollout of pre-exposure prophylaxis (PrEP) for HIV prevention to priority populations, including young women, is expanding in sub-Saharan Africa. However, existing barriers to PrEP rollout at the individual, community and policy levels could slow progress and impede the success of PrEP implementation programs. In order to achieve success in HIV prevention, it is crucial to address these barriers, particularly among young women, a population especially vulnerable to HIV. In this dissertation, we evaluated the links among risk perception, sexual behavior and PrEP adherence in serodiscordant couples, evaluated the impact of incorporating HIVST in PrEP delivery for young women and assessed the cost of delivering PrEP to young women. In Aim 1, we used data from HIV-negative adults enrolled in a study of PrEP and antiretroviral therapy for HIV-serodiscordant couples in Kenya and Uganda to examine associations between: 1) condom use and risk perception and 2) risk perception and PrEP adherence. In Aim 2, we offered HIV self-testing (HIVST) to young women enrolled in a PrEP implementation study in two family planning clinics and assessed satisfaction with HIV testing and clinic experience, and the impact of HIVST on PrEP delivery procedures. In Aim 3, using the same population as that in Aim 2, we used micro-costing methods to estimate the incremental cost of delivering PrEP to young women. We found that sexual behavior aligned with perceived HIV risk, which can facilitate an HIV-negative individual's decisions about PrEP use. Additionally, we found HIVST to be feasible and acceptable for young women using PrEP, highlighting the need to evaluate its utility to streamline PrEP delivery and provide more testing options for young women on PrEP. Lastly, using practical data from PrEP implementation, we estimated the cost of delivering PrEP to young women, providing valuable data to inform budget impact and cost-effectiveness analyses as well as local resource allocation for scale-up of PrEP delivery to young women. Collectively, these studies addressed some of the barriers to PrEP delivery, proposed solutions to these barriers and drew attention to priority research needs for PrEP delivery to young women.

Author: National Research Council (U.S.). Panel on Data and Research Priorities for Arresting AIDS in Sub-Saharan Africa
Publisher: National Academies
ISBN:
Category : Medical
Languages : en
Pages : 36

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The AIDS epidemic in Sub-Saharan Africa continues to affect all facets of life throughout the subcontinent. Deaths related to AIDS have driven down the life expectancy rate of residents in Zambia, Kenya, and Uganda with far-reaching implications. This book details the current state of the AIDS epidemic in Africa and what is known about the behaviors that contribute to the transmission of the HIV infection. It lays out what research is needed and what is necessary to design more effective prevention programs.

Author: Elizabeth M. Irungu
Publisher:
ISBN:
Category :
Languages : en
Pages : 138

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Book Description
Daily, oral pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) is a highly potent HIV prevention intervention with potential to reduce HIV incidence among populations at risk of HIV in Africa if delivered with sufficient coverage. There are extensive data from high-income countries describing diverse settings in which PrEP services are offered. However, data describing PrEP scale-up models in low- and middle-income countries are limited. Public HIV care and treatment programs in Africa have been very successful at scaling up antiretroviral therapy (ART) over the last 15 years and are an attractive choice for integration of PrEP delivery. The main objective of the work described in this dissertation was to evaluate the effectiveness of PrEP implementation and integration in public HIV care clinics. The specific aims include to 1) conduct a step wedge cluster randomized trial of PrEP integration in public health HIV care clinics (the Partners Scale-Up Project) and evaluate impact; 2) conduct a process evaluation of PrEP integration in public HIV care clinics in Kenya, focusing on adaptation; 3) develop and evaluate the effectiveness of an on-site modular training approach to amplify the number of health care providers trained to deliver PrEP in public HIV care clinics in Kenya; and 4) summarize early PrEP rollout in African settings, challenges encountered and opportunities to expand implementation. We found evidence that integration of PrEP in public HIV clinics was feasible. By improving the capacity of health providers in those care clinics to offer PrEP services through training and technical support, PrEP uptake increased more than 20-fold and was sustained. With existing personnel and infrastructure, the high-volume HIV care clinics efficiently reached partners of HIV infected persons and other populations at HIV risk. PrEP users had reasonable continuation rates and objective evidence of high adherence. Using qualitative methods, we found that clinics made pragmatic, effective adaptations to non-core components of PrEP delivery services and to their routine practice to address challenges in PrEP delivery. We established that clinics that instituted some of the adaptations had above average monthly PrEP initiation and continuation rates. To amplify PrEP delivery in public health facilities, we developed and evaluated an innovative on-site modular training approach. We found that this approach was acceptable and it enabled many health providers to receive PrEP training conveniently and at a relatively low cost. Finally, our summary of early PrEP roll out in Africa revealed that there was high interest in PrEP among all populations at risk of acquiring HIV, but individuals did not continue use as expected. We suggested strategies to make PrEP delivery efficient, including delivery within community pharmacies, use of peers, services availed in low tier facilities and exploration of one-stop services to make PrEP delivery less burdensome. The collective results presented in this dissertation illustrate that integration of PrEP services in public HIV care clinics in Kenya is a successful and sustainable model for PrEP implementation. We posit that this model can be scaled up in African countries planning to set up PrEP programs.