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Moolla H, Phillips A, Ten Brink D, Mudimu E, Stover J, Bansi-Matharu L, Martin-Hughes R, Wulan N, Cambiano V, Smith J, Bershteyn A, Meyer-Rath G, Jamieson L, Johnson LF. A quantitative assessment of the consistency of projections from five mathematical models of the HIV epidemic in South Africa: a model comparison study. BMC Public Health 2023; 23:2119. [PMID: 37891514 PMCID: PMC10612295 DOI: 10.1186/s12889-023-16995-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 10/14/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Mathematical models are increasingly used to inform HIV policy and planning. Comparing estimates obtained using different mathematical models can test the robustness of estimates and highlight research gaps. As part of a larger project aiming to determine the optimal allocation of funding for HIV services, in this study we compare projections from five mathematical models of the HIV epidemic in South Africa: EMOD-HIV, Goals, HIV-Synthesis, Optima, and Thembisa. METHODS The five modelling groups produced estimates of the total population, HIV incidence, HIV prevalence, proportion of people living with HIV who are diagnosed, ART coverage, proportion of those on ART who are virally suppressed, AIDS-related deaths, total deaths, and the proportion of adult males who are circumcised. Estimates were made under a "status quo" scenario for the period 1990 to 2040. For each output variable we assessed the consistency of model estimates by calculating the coefficient of variation and examining the trend over time. RESULTS For most outputs there was significant inter-model variability between 1990 and 2005, when limited data was available for calibration, good consistency from 2005 to 2025, and increasing variability towards the end of the projection period. Estimates of HIV incidence, deaths in people living with HIV, and total deaths displayed the largest long-term variability, with standard deviations between 35 and 65% of the cross-model means. Despite this variability, all models predicted a gradual decline in HIV incidence in the long-term. Projections related to the UNAIDS 95-95-95 targets were more consistent, with the coefficients of variation below 0.1 for all groups except children. CONCLUSIONS While models produced consistent estimates for several outputs, there are areas of variability that should be investigated. This is important if projections are to be used in subsequent cost-effectiveness studies.
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Affiliation(s)
- Haroon Moolla
- Centre for Infectious Disease Epidemiology and Research, Faculty of Health Sciences, University of Cape Town, Anzio Road, Cape Town, 7925, Observatory, South Africa.
| | | | | | - Edinah Mudimu
- Department of Decision Sciences, University of South Africa, Pretoria, South Africa
| | | | | | | | | | | | | | - Anna Bershteyn
- Department of Population Health, NYU Grossman School of Medicine, New York, USA
| | - Gesine Meyer-Rath
- Center for Global Health and Development, Boston University, Boston, USA
- Health Economics and Epidemiology Research Office, University of the Witwatersrand, Johannesburg, South Africa
| | - Lise Jamieson
- Health Economics and Epidemiology Research Office, University of the Witwatersrand, Johannesburg, South Africa
- Department of Medical Microbiology, Amsterdam University Medical Centre, Amsterdam, The Netherlands
| | - Leigh F Johnson
- Centre for Infectious Disease Epidemiology and Research, Faculty of Health Sciences, University of Cape Town, Anzio Road, Cape Town, 7925, Observatory, South Africa
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Milali MP, Resar D, Kaftan D, Campbell J, Olowu A, Edwards D, Platais I, Kim HY, Jenkins S, Bershteyn A. Cost-effectiveness of the dual prevention pill for contraception and HIV pre-exposure prophylaxis. FRONTIERS IN REPRODUCTIVE HEALTH 2023; 5:1144217. [PMID: 37266447 PMCID: PMC10230827 DOI: 10.3389/frph.2023.1144217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/24/2023] [Indexed: 06/03/2023] Open
Abstract
Introduction Women in sub-Saharan Africa (SSA) experience the world's highest rates of both HIV infection and unintended pregnancy. The Dual Prevention Pill (DPP) is a novel multipurpose prevention technology (MPT) that co-formulates HIV pre-exposure prophylaxis (PrEP) and combined hormonal oral contraception into a single daily pill. As a dual indication product, the DPP may be preferred by women facing these overlapping health risks. However, most SSA countries face severe healthcare resource constraints. Research is needed to assess whether, in what populations, and in what use cases the DPP would be cost-effective. Methods We augmented an agent-based SSA HIV model with maternal health parameters including unintended pregnancy, abortion, and maternal mortality. Based on a previous market analysis, we assumed a primary DPP user population of current oral contraceptive users ages 25-49, and alternative user populations in different risk groups (age 15-24, sex workers, HIV-serodiscordant couples) and baseline product use profiles (unmet need for contraception, oral PrEP use, condom use). In three geographies (western Kenya, Zimbabwe, South Africa), we estimated HIV infections averted, pregnancies averted, disability-adjusted life-years (DALYs) averted, and the incremental cost-effectiveness ratio (ICER) over a 30-year time horizon, assuming equivalent adherence to the DPP as to oral contraceptives, higher adherence, or lower adherence. Results The DPP is likely to be a cost-effective alternative to oral PrEP among users in need of contraception. Among women not already using PrEP, the DPP is likely to be cost-saving in sex workers and serodiscordant couples. The DPP is unlikely to be cost-effective in oral contraceptive users in the general population. Switching from oral contraception to the DPP could be net harmful in some settings and populations if it were to substantially reduces adherence to oral contraception. Results were robust to a range of time horizons or discount rates. Conclusion The DPP has the potential to be cost-effective and cost-saving in populations at substantial HIV risk. Outcomes are sensitive to adherence, implying that effective counseling and decision-making tools for users considering the DPP will be essential. More research is needed to understand real-life adherence patterns and ensure health benefits achieved from contraception alone are not lost.
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Affiliation(s)
- Masabho P. Milali
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Danielle Resar
- Clinton Health Access Initiative, Boston, MA, United States
| | - David Kaftan
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, United States
| | | | - Adebanjo Olowu
- Clinton Health Access Initiative, Boston, MA, United States
| | - Danny Edwards
- Clinton Health Access Initiative, Boston, MA, United States
| | - Ingrida Platais
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Hae-Young Kim
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Sarah Jenkins
- Clinton Health Access Initiative, Boston, MA, United States
| | - Anna Bershteyn
- Department of Population Health, NYU Grossman School of Medicine, New York, NY, United States
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Luseno WK, Rennie S, Gilbertson A. A review of public health, social and ethical implications of voluntary medical male circumcision programs for HIV prevention in sub-Saharan Africa. Int J Impot Res 2023; 35:269-278. [PMID: 34702986 PMCID: PMC8545773 DOI: 10.1038/s41443-021-00484-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/06/2021] [Accepted: 10/13/2021] [Indexed: 12/22/2022]
Abstract
Ideally, the benefits of public health interventions should outweigh any associated harms, burdens, and adverse unintended consequences. The intended benefit of voluntary medical male circumcision (VMMC) programs in eastern and southern Africa (ESA) is the reduction of HIV infections. We review the literature for evidence of reductions in HIV incidence, evaluate the extent to which decreases in HIV incidence can be reasonably attributed to VMMC programs, and summarize social harms and ethical concerns associated with these programs. Review findings suggest that HIV incidence had been declining across ESA since before the large-scale rollout of VMMC as a public health intervention, and that this decline may be due to the combined effects of HIV prevention and treatment interventions, such as expanded antiretroviral therapy. The independent effect of VMMC programs in reducing HIV infections at the population level remains unknown. On the other hand, VMMC-associated evidence is increasing for the existence of negative social impacts such as stigmatization and/or discrimination, and ethically problematic practices, including lack of informed consent. We conclude that the relationship between the benefits and burdens of VMMC programs may be more unfavorable than what has been commonly suggested by proponents of global VMMC campaigns.
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Affiliation(s)
| | - Stuart Rennie
- Department of Social Medicine, University of North Carolina, Chapel Hill, NC, USA
- UNC Center for Bioethics, University of North Carolina, Chapel Hill, NC, USA
| | - Adam Gilbertson
- Pacific Institute for Research and Evaluation (PIRE), Chapel Hill, NC, USA
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4
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Bansi-Matharu L, Mudimu E, Martin-Hughes R, Hamilton M, Johnson L, Ten Brink D, Stover J, Meyer-Rath G, Kelly SL, Jamieson L, Cambiano V, Jahn A, Cowan FM, Mangenah C, Mavhu W, Chidarikire T, Toledo C, Revill P, Sundaram M, Hatzold K, Yansaneh A, Apollo T, Kalua T, Mugurungi O, Kiggundu V, Zhang S, Nyirenda R, Phillips A, Kripke K, Bershteyn A. Cost-effectiveness of voluntary medical male circumcision for HIV prevention across sub-Saharan Africa: results from five independent models. Lancet Glob Health 2023; 11:e244-e255. [PMID: 36563699 PMCID: PMC10005968 DOI: 10.1016/s2214-109x(22)00515-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 10/11/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Voluntary medical male circumcision (VMMC) has been a recommended HIV prevention strategy in sub-Saharan Africa since 2007, particularly in countries with high HIV prevalence. However, given the scale-up of antiretroviral therapy programmes, it is not clear whether VMMC still represents a cost-effective use of scarce HIV programme resources. METHODS Using five existing well described HIV mathematical models, we compared continuation of VMMC for 5 years in men aged 15 years and older to no further VMMC in South Africa, Malawi, and Zimbabwe and across a range of setting scenarios in sub-Saharan Africa. Outputs were based on a 50-year time horizon, VMMC cost was assumed to be US$90, and a cost-effectiveness threshold of US$500 was used. FINDINGS In South Africa and Malawi, the continuation of VMMC for 5 years resulted in cost savings and health benefits (infections and disability-adjusted life-years averted) according to all models. Of the two models modelling Zimbabwe, the continuation of VMMC for 5 years resulted in cost savings and health benefits by one model but was not as cost-effective according to the other model. Continuation of VMMC was cost-effective in 68% of setting scenarios across sub-Saharan Africa. VMMC was more likely to be cost-effective in modelled settings with higher HIV incidence; VMMC was cost-effective in 62% of settings with HIV incidence of less than 0·1 per 100 person-years in men aged 15-49 years, increasing to 95% with HIV incidence greater than 1·0 per 100 person-years. INTERPRETATION VMMC remains a cost-effective, often cost-saving, prevention intervention in sub-Saharan Africa for at least the next 5 years. FUNDING Bill & Melinda Gates Foundation for the HIV Modelling Consortium.
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Affiliation(s)
| | - Edinah Mudimu
- Department of Decision Sciences, University of South Africa, Pretoria, South Africa
| | | | | | - Leigh Johnson
- Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa
| | | | | | - Gesine Meyer-Rath
- Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Global Health, Boston University School of Public Health, Boston, MA, USA
| | | | - Lise Jamieson
- Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Andreas Jahn
- Ministry of Health, Lilongwe, Malawi; International Training and Education Center for Health, Department of Global Health, University of Washington, Seattle, WA, USA
| | - Frances M Cowan
- Center for Sexual Health and HIV/AIDS Research, Harare, Zimbabwe; Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Collin Mangenah
- Center for Sexual Health and HIV/AIDS Research, Harare, Zimbabwe; Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Webster Mavhu
- Center for Sexual Health and HIV/AIDS Research, Harare, Zimbabwe; Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Carlos Toledo
- Division of Global HIV/AIDS and Tuberculosis, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Paul Revill
- Centre for Health Economics, University of York, York, UK
| | - Maaya Sundaram
- Global Development Program, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Karin Hatzold
- Population Services International, Washington, DC, USA
| | - Aisha Yansaneh
- United States Agency for International Development, Washington, DC, USA
| | - Tsitsi Apollo
- Ministry of Health and Child Welfare, Harare, Zimbabwe
| | - Thoko Kalua
- Department of HIV and AIDS, Ministry of Health Malawi, Lilongwe, Malawi; Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | | | - Valerian Kiggundu
- United States Agency for International Development, Washington, DC, USA
| | - Shufang Zhang
- The Global Fund to Fight AIDS, Tuberculosis, and Malaria, Geneva, Switzerland
| | - Rose Nyirenda
- Department of HIV and AIDS, Ministry of Health Malawi, Lilongwe, Malawi
| | | | | | - Anna Bershteyn
- Department of Population Health, New York University Grossman School of Medicine, New York, NY, USA
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Johnson LF, Meyer-Rath G, Dorrington RE, Puren A, Seathlodi T, Zuma K, Feizzadeh A. The Effect of HIV Programs in South Africa on National HIV Incidence Trends, 2000-2019. J Acquir Immune Defic Syndr 2022; 90:115-123. [PMID: 35125471 DOI: 10.1097/qai.0000000000002927] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/18/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent studies have shown HIV incidence declines at a population level in several African countries. However, these studies have not directly quantified the extent to which incidence declines are attributable to different HIV programs. METHODS We calibrated a mathematical model of the South African HIV epidemic to age- and sex-specific data from antenatal surveys, household surveys, and death registration, using a Bayesian approach. The model was also parameterized using data on self-reported condom use, voluntary medical male circumcision (VMMC), HIV testing, and antiretroviral treatment (ART). Model estimates of HIV incidence were compared against the incidence rates that would have been expected had each program not been implemented. RESULTS The model estimated incidence in 15-49 year olds of 0.84% (95% CI: 0.75% to 0.96%) at the start of 2019. This represents a 62% reduction (95% CI: 55% to 66%) relative to 2000, a 47% reduction (95% CI: 42% to 51%) relative to 2010, and a 73% reduction (95% CI: 68% to 77%) relative to the incidence that would have been expected in 2019 in the absence of any interventions. The reduction in incidence in 2019 because of interventions was greatest for ART and condom promotion, with VMMC and behavior change after HIV testing having relatively modest impacts. HIV program impacts differed significantly by age and sex, with condoms and VMMC having greatest impact in youth, and overall incidence reductions being greater in men than in women. CONCLUSIONS HIV incidence in South Africa has declined substantially since 2000, with ART and condom promotion contributing most significantly to this decline.
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Affiliation(s)
- Leigh F Johnson
- Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine University of Cape Town, Cape Town, South Africa
| | - Gesine Meyer-Rath
- Health Economics and Epidemiology Research Office, Wits Health Consortium, University of Witwatersrand, Johannesburg, South Africa
- Department of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Global Health, Boston University School of Public Health, Boston, MA
| | - Rob E Dorrington
- Centre for Actuarial Research, School of Management Studies, University of Cape Town, Cape Town, South Africa
| | - Adrian Puren
- Division of Virology, School of Pathology, University of Witwatersrand, Johannesburg, South Africa
| | - Thapelo Seathlodi
- Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine University of Cape Town, Cape Town, South Africa
| | - Khangelani Zuma
- Human Sciences Research Council, Pretoria, South Africa ; and
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Bershteyn A, Kim HY, Scott Braithwaite R. Real-Time Infectious Disease Modeling to Inform Emergency Public Health Decision Making. Annu Rev Public Health 2022; 43:397-418. [DOI: 10.1146/annurev-publhealth-052220-093319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Infectious disease transmission is a nonlinear process with complex, sometimes unintuitive dynamics. Modeling can transform information about a disease process and its parameters into quantitative projections that help decision makers compare public health response options. However, modelers face methodologic challenges, data challenges, and communication challenges, which are exacerbated under the time constraints of a public health emergency. We review methods, applications, challenges and opportunities for real-time infectious disease modeling during public health emergencies, with examples drawn from the two deadliest pandemics in recent history: HIV/AIDS and coronavirus disease 2019 (COVID-19). Expected final online publication date for the Annual Review of Public Health, Volume 43 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Anna Bershteyn
- New York University Grossman School of Medicine, New York, NY, USA
| | - Hae-Young Kim
- New York University Grossman School of Medicine, New York, NY, USA
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7
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Bershteyn A, Mudimu E, Platais I, Mwalili S, Zulu JE, Mwanza WN, Kripke K. Understanding the Evolving Role of Voluntary Medical Male Circumcision as a Public Health Strategy in Eastern and Southern Africa: Opportunities and Challenges. Curr HIV/AIDS Rep 2022; 19:526-536. [PMID: 36459306 PMCID: PMC9759505 DOI: 10.1007/s11904-022-00639-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2022] [Indexed: 12/05/2022]
Abstract
PURPOSE OF REVIEW Voluntary male medical circumcision (VMMC) has been a cornerstone of HIV prevention in Eastern and Southern Africa (ESA) and is credited in part for declines in HIV incidence seen in recent years. However, these HIV incidence declines change VMMC cost-effectiveness and how it varies across populations. RECENT FINDINGS Mathematical models project continued cost-effectiveness of VMMC in much of ESA despite HIV incidence declines. A key data gap is how demand generation cost differs across age groups and over time as VMMC coverage increases. Additionally, VMMC models usually neglect non-HIV effects of VMMC, such as prevention of other sexually transmitted infections and medical adverse events. While small compared to HIV effects in the short term, these could become important as HIV incidence declines. Evidence to date supports prioritizing VMMC in ESA despite falling HIV incidence. Updated modeling methodologies will become necessary if HIV incidence reaches low levels.
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Affiliation(s)
- Anna Bershteyn
- Department of Population Health, New York University Grossman School of Medicine, 227 East 30th Street, New York, NY 10016 USA
| | - Edinah Mudimu
- Department of Decision Sciences, College of Economic and Management Sciences, University of South Africa, Pretoria, Gauteng South Africa
| | - Ingrida Platais
- Department of Population Health, New York University Grossman School of Medicine, 227 East 30th Street, New York, NY 10016 USA
| | - Samuel Mwalili
- Strathmore Institute of Mathematical Sciences, Strathmore University, Nairobi, Kenya
| | - James E. Zulu
- Zambia Field Epidemiology Training Program, Workforce Development Cluster, Zambia National Public Health Institute, Lusaka, Zambia
| | - Wiza N. Mwanza
- Directorate of Public Health and Research, Ministry of Health, Lusaka, Zambia
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Garnett GP. Reductions in HIV incidence are likely to increase the importance of key population programmes for HIV control in sub-Saharan Africa. J Int AIDS Soc 2021; 24 Suppl 3:e25727. [PMID: 34189844 PMCID: PMC8242973 DOI: 10.1002/jia2.25727] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 03/24/2021] [Accepted: 04/20/2021] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION An efficient HIV response requires that resources be focussed on effective interventions for those most at risk of acquiring and transmitting infection. As HIV epidemics evolve the distribution of HIV across key and other populations will change. Here, the epidemiological concepts underpinning these changes are described and the importance of appropriate allocation of effective interventions is discussed. DISCUSSION In many sub-Saharan African countries HIV epidemics have been categorized as "generalized," and HIV testing, treatment and prevention interventions have focussed on the "general" population. As HIV epidemics are better controlled the relative importance of "key" populations will increase, dominating the ongoing burden of disease and providing the potential for repeated outbreaks of HIV if interventions are relaxed. The basic reproductive number (R0 ) describes the potential for an infectious disease to spread at the boundary of invasion or elimination, whereas the effective reproduction number (Rt ) describes the current potential for spread. Heterogeneity in risk means that while Rt is temporarily below one and prevalence declining, the R0 can remain above one, preventing eventual elimination. Patterns of HIV acquisition are often used to guide interventions but inadequately capture the transmission dynamics of the virus and the most efficient approach to controlling HIV. Risks for HIV acquisition are not identical to risks for HIV transmission and will change depending on the epidemiological context. In addition to the challenges in measuring HIV transmission dynamics, there is a tension between using epidemiology to drive the HIV response and the social and political realities constraining how programmes and providers can practically and appropriately focus on key populations and maintain political support. In addition to being well focussed, interventions need to be effective and cost-effective, which requires a better understanding of packages of interventions rather than specific tools. CONCLUSIONS Continued control of HIV will increasingly rely on resources, programmes and interventions supporting key populations. Current epidemiological and programmatic approaches for key populations in sub-Saharan Africa are insufficient with a need for an improved understanding of local epidemiology and the effectiveness of interventions.
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Affiliation(s)
- Geoff P Garnett
- Tuberculosis and HIV Strategic TeamBill & Melinda Gates FoundationSeattleWAUSA
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