Updates to the spectrum model to estimate key HIV indicators for adults and children

Patterns of Rising HIV Positivity in Northern Madagascar: Evidence of an Urgent Public Health Concern

Despite over two decades of progress against HIV/AIDS in adjacent sub-Saharan Africa, HIV rates and deaths due to AIDS are exponentially rising in Madagascar. Furthermore, a growing body of evidence suggests that, due to a scarcity of general-population screening data, even the startling increase demonstrated by official models vastly underestimates the true population prevalence of HIV. We aimed to implement a real-world HIV screening and treatment protocol to serve a general population stemming from across northern Madagascar. In collaboration with the Malagasy Ministry of Health, we provided point-of-care HIV screening and confirmatory testing for over 1000 participants from 73 towns, villages, and cities. We recorded an overall HIV prevalence of 2.94%. Notably, we observed a 13.1% HIV prevalence rate among urban populations and showed that proximity to a major route of travel was significantly associated with HIV risk. We also observed a link between HIV risk and various occupations, including those associated with increased mobility (such as mining). Importantly, all HIV-positive individuals were initiated on antiretroviral therapy in concordance with local health authorities. To our knowledge, this study marks the largest primary test data-based HIV study to date among Madagascar's general population, showing a greatly higher HIV prevalence (2.9%) than previously reported modeling-based figures (0.4%). Our rates aligned with the pattern of higher prevalence demonstrated in smaller general-population screening studies occurring more commonly prior to political strife in the mid-2000s. These findings demonstrate evidence of a growing HIV epidemic in northern Madagascar and underscore the need for future investment into more comprehensive HIV screening and control initiatives in Madagascar.

Methods and Assumptions for Estimating Key HIV Indicators in the UNAIDS Annual Estimates Process

BACKGROUND

Each year UNAIDS supports national teams to estimate key HIV indicators using their latest data. These estimates are produced using a collection of models and software tools. This paper describes the demographic and HIV projection models used in this process.

METHODS

The demographic model (DemProj) projects the population by sex and single age for each year of the estimate. This information is fed into the HIV model (AIDS Impact Model) to estimate key HIV indicators. The model uses program, survey and surveillance data along with incidence trends produced through 1 of several separate models, to estimate new HIV infections, HIV-related deaths, and the population living with HIV by sex, age, CD4 category, and treatment status.

RESULTS

These models allow the annual production of estimates of key HIV indicators including uncertainty intervals. This information is used to track progress toward national and global goals and to develop national strategic plans, Global Fund applications and PEPFAR country operational plans.

CONCLUSIONS

Under the guidance of the UNAIDS Reference Group on Estimates, Modeling and Projections, these models are updated on a regular basis in response to evolving programmatic needs, new data, and analyses. This process of continuous review and improvement has led to mature models that make the best use of available data to provide estimates of indicators important to monitoring progress and developing future plans.

Subnational HIV incidence trends in Malawi: large, heterogeneous declines across space

The rate of new HIV infections globally has decreased substantially from its peak in the late 1990s, but the epidemic persists and remains highest in many countries in eastern and southern Africa. Previous research hypothesised that, as the epidemic recedes, it will become increasingly concentrated among sub-populations and geographic areas where transmission is the highest and that are least effectively reached by treatment and prevention services. However, empirical data on subnational HIV incidence trends is sparse, and the local transmission rates in the context of effective treatment scale-up are unknown. In this work, we developed a novel Bayesian spatio-temporal epidemic model to estimate adult HIV prevalence, incidence and treatment coverage at the district level in Malawi from 2010 through the end of 2021. We found that HIV incidence decreased in every district of Malawi between 2010 and 2021 but the rate of decline varied by area. National-level treatment coverage more than tripled between 2010 and 2021 and more than doubled in every district. Large increases in treatment coverage were associated with declines in HIV transmission, with 12 districts having incidence-prevalence ratios of 0.03 or less (a previously suggested threshold for epidemic control). Across districts, incidence varied more than HIV prevalence and ART coverage, suggesting that the epidemic is becoming increasingly spatially concentrated. Our results highlight the success of the Malawi HIV treatment programme over the past decade, with large improvements in treatment coverage leading to commensurate declines in incidence. More broadly, we demonstrate the utility of spatially resolved HIV modelling in generalized epidemic settings. By estimating temporal changes in key epidemic indicators at a relatively fine spatial resolution, we were able to directly assess, for the first time, whether the ART scaleup in Malawi resulted in spatial gaps or hotspots. Regular use of this type of analysis will allow HIV program managers to monitor the equity of their treatment and prevention programmes and their subnational progress towards epidemic control.

Disease progression and mortality with untreated HIV infection: evidence synthesis of HIV seroconverter cohorts, antiretroviral treatment clinical cohorts and population-based survey data

Introduction

Model‐based estimates of key HIV indicators depend on past epidemic trends that are derived based on assumptions about HIV disease progression and mortality in the absence of antiretroviral treatment (ART). Population‐based HIV Impact Assessment (PHIA) household surveys conducted between 2015 and 2018 found substantial numbers of respondents living with untreated HIV infection. CD4 cell counts measured in these individuals provide novel information to estimate HIV disease progression and mortality rates off ART.

Methods

We used Bayesian multi‐parameter evidence synthesis to combine data on (1) cross‐sectional CD4 cell counts among untreated adults living with HIV from 10 PHIA surveys, (2) survival after HIV seroconversion in East African seroconverter cohorts, (3) post‐seroconversion CD4 counts and (4) mortality rates by CD4 count predominantly from European, North American and Australian seroconverter cohorts. We used incremental mixture importance sampling to estimate HIV natural history and ART uptake parameters used in the Spectrum software. We validated modelled trends in CD4 count at ART initiation against ART initiator cohorts in sub‐Saharan Africa.

Results

Median untreated HIV survival decreased with increasing age at seroconversion, from 12.5 years [95% credible interval (CrI): 12.1–12.7] at ages 15–24 to 7.2 years (95% CrI: 7.1–7.7) at ages 45–54. Older age was associated with lower initial CD4 counts, faster CD4 count decline and higher HIV‐related mortality rates. Our estimates suggested a weaker association between ART uptake and HIV‐related mortality rates than previously assumed in Spectrum. Modelled CD4 counts in untreated people living with HIV matched recent household survey data well, though some intercountry variation in frequencies of CD4 counts above 500 cells/mm³ was not explained. Trends in CD4 counts at ART initiation were comparable to data from ART initiator cohorts. An alternate model that stratified progression and mortality rates by sex did not improve model fit appreciably.

Conclusions

Synthesis of multiple data sources results in similar overall survival as previous Spectrum parameter assumptions but implies more rapid progression and longer survival in lower CD4 categories. New natural history parameter values improve consistency of model estimates with recent cross‐sectional CD4 data and trends in CD4 counts at ART initiation.

Updates to Spectrum's case surveillance and vital registration tool for HIV estimates and projections

INTRODUCTION

The Case Surveillance and Vital Registration (CSAVR) model within Spectrum estimates HIV incidence trends from surveillance data on numbers of new HIV diagnoses and HIV-related deaths. This article describes developments of the CSAVR tool to more flexibly model diagnosis rates over time, estimate incidence patterns by sex and age group and by key population group.

METHODS

We modelled HIV diagnosis rate trends as a mixture of three factors, including temporal and opportunistic infection components. The tool was expanded to estimate incidence rate ratios by sex and age for countries with disaggregated reporting of new HIV diagnoses and AIDS deaths, and to account for information on key populations such as men who have sex with men (MSM), males who inject drugs (MWID), female sex workers (FSW) and females who inject drugs (FWID). We used a Bayesian framework to calibrate the tool in 71 high-income or low-HIV burden countries.

RESULTS

Across countries, an estimated median 89% (interquartile range [IQR]: 78%-96%) of HIV-positive adults knew their status in 2019. Mean CD4 counts at diagnosis were stable over time, with a median of 456 cells/μl (IQR: 391-508) across countries in 2019. In European countries reporting new HIV diagnoses among key populations, median estimated proportions of males that are MSM and MWID was 1.3% (IQR: 0.9%-2.0%) and 0.56% (IQR: 0.51%-0.64%), respectively. The median estimated proportions of females that are FSW and FWID were 0.36% (IQR: 0.27%-0.45%) and 0.14 (IQR: 0.13%-0.15%), respectively. HIV incidence per 100 person-years increased among MSM, with median estimates reaching 0.43 (IQR: 0.29-1.73) in 2019, but remained stable in MWID, FSW and FWID, at around 0.12 (IQR: 0.04-1.9), 0.09 (IQR: 0.06-0.69) and 0.13% (IQR: 0.08%-0.91%) in 2019, respectively. Knowledge of HIV status among HIV-positive adults gradually increased since the early 1990s to exceed 75% in more than 75% of countries in 2019 among each key population.

CONCLUSIONS

CSAVR offers an approach to using routine surveillance and vital registration data to estimate and project trends in both HIV incidence and knowledge of HIV status.

ART initiations following community-based distribution of HIV self-tests: meta-analysis and meta-regression of STAR Initiative data

INTRODUCTION

Measuring linkage after community-based testing, particularly HIV self-testing (HIVST), is challenging. Here, we use data from studies of community-based HIVST distribution, conducted within the STAR Initiative, to assess initiation of antiretroviral therapy (ART) and factors driving differences in linkage rates.

METHODS

Five STAR studies evaluated HIVST implementation in Malawi, Zambia and Zimbabwe. New ART initiations during the months of intervention at clinics in HIVST and comparison areas were presented graphically, and study effects combined using meta-analysis. Meta-regression was used to estimate associations between the impact of community-based HIVST distribution and indicators of implementation context, intensity and reach. Effect size estimates used (1) prespecified trial definitions of ART timing and comparator facilities and (2) exploratory definitions accounting for unexpected diffusion of HIVST into comparison areas and periods with less distribution of HIVST than was expected.

RESULTS

Compared with arms with standard testing only, ART initiations were higher in clinics in HIVST distribution areas in 4/5 studies. The prespecified meta-analysis found positive but variable effects of HIVST on facility ART initiations (RR: 1.14, 95% CI 0.93 to 1.40; p=0.21). The exploratory meta-analysis found a stronger impact of HIVST distribution on ART initiations (RR: 1.29, 95% CI 1.08 to 1.55, p=0.02).ART initiations were higher in studies with greater self-reported population-level intensity of HIVST use (RR: 1.12; 95% CI 1.04 to 1.21; p=0.02.), but did not differ by national-level indicators of ART use among people living with HIV, number of HIVST kits distributed per 1000 population, or self-reported knowledge of how to link to care after a reactive HIVST.

CONCLUSION

Community-based HIVST distribution has variable effect on ART initiations compared with standard testing service alone. Optimising both support for and approach to measurement of effective and timely linkage or relinkage to HIV care and prevention following HIVST is needed to maximise impact and guide implementation strategies.

Can non-fatal burden estimates from the Global Burden of Disease study be used locally? An investigation using models of stroke and diabetes for South Africa

Background: The Global Burden of Disease (GBD) approach estimates disease burden by combining fatal (years of life lost) and non-fatal burden prevalence-based years of life lived with disability (PYLDs) estimates. Although South Africa has data to estimate mortality, prevalence data to estimate non-fatal burden are sparse. PYLD estimates from the GBD study for South Africa can potentially be used. However, there is a divergence in mortality estimates for South Africa between the second South African National Burden of Disease (SANBD2) and 2013 GBD studies. Objective: We investigated the feasibility of utilising GBD PYLD estimates for stroke and diabetes by exploring different disease modelling scenarios. Method: DisMod II software-generated South African stroke and diabetes PYLDs for 2010 from models using local epidemiological parameters and demographic data for people 20-79 years old. We investigated the impact on PYLD estimates of 1) differences in the cause-of-death envelope, 2) differences in the cause-specific mortality estimates (increase/decrease by 15% for stroke and 30% for diabetes), and 3) difference using local disease parameters compared to other country or region parameters. Differences were expressed as ratios, average ratios and ratio ranges. Results: Using the GBD cause-of-death envelope (16% more deaths than SANBD2) and holding other parameters constant yielded age-specific ratios of PYLDs for stroke and diabetes ranging between 0.89 and 1.07 (average 0.98) for males. Similar results were observed for females. A 15% change in age-specific stroke mortality showed little difference in the ratio comparison of PYLDs (range 0.98-1.02) while a 30% change in age-specific diabetes mortality resulted in a ratio range of 0.96-1.07 for PYLDs depending on age. Conclusion: This study showed that GBD non-fatal burden estimates (PYLDs) can be used for stroke and diabetes non-fatal burden in the SANBD2 study.

Modelling impact and cost-effectiveness of oral pre-exposure prophylaxis in 13 low-resource countries

INTRODUCTION

Oral pre-exposure prophylaxis (PrEP) provision is a priority intervention for high HIV prevalence settings and populations at substantial risk of HIV acquisition. This mathematical modelling analysis estimated the impact, cost and cost-effectiveness of scaling up oral PrEP in 13 countries.

METHODS

We projected the impact and cost-effectiveness of oral PrEP between 2018 and 2030 using a combination of the Incidence Patterns Model and the Goals model. We created four PrEP rollout scenarios involving three priority populations-female sex workers (FSWs), serodiscordant couples (SDCs) and adolescent girls and young women (AGYW)-both with and without geographic prioritization. We applied the model to 13 countries (Eswatini, Ethiopia, Haiti, Kenya, Lesotho, Mozambique, Namibia, Nigeria, Tanzania, Uganda, Zambia and Zimbabwe). The base case assumed achievement of the Joint United Nations Programme on HIV/AIDS 90-90-90 antiretroviral therapy targets, 90% male circumcision coverage by 2020 and 90% efficacy and adherence levels for oral PrEP.

RESULTS

In the scenarios we examined, oral PrEP averted 3% to 8% of HIV infections across the 13 countries between 2018 and 2030. For all but three countries, more than 50% of the HIV infections averted by oral PrEP in the scenarios we examined could be obtained by rollout to FSWs and SDCs alone. For several countries, expanding oral PrEP to include medium-risk AGYW in all regions greatly increased the impact. The efficiency and impact benefits of geographic prioritization of rollout to AGYW varied across countries. Variations in cost-effectiveness across countries reflected differences in HIV incidence and expected variations in unit cost. For most countries, rolling out oral PrEP to FSWs, SDCs and geographically prioritized AGYW was not projected to have a substantial impact on the supply chain for antiretroviral drugs.

CONCLUSIONS

These modelling results can inform prioritization, target-setting and other decisions related to oral PrEP scale-up within combination prevention programmes. We caution against extensive use given limitations in cost data and implementation approaches. This analysis highlights some of the immediate challenges facing countries-for example, trade-offs between overall impact and cost-effectiveness-and emphasizes the need to improve data availability and risk assessment tools to help countries make informed decisions.

Modeling methods for estimating HIV incidence: a mathematical review

Estimating HIV incidence is crucial for monitoring the epidemiology of this infection, planning screening and intervention campaigns, and evaluating the effectiveness of control measures. However, owing to the long and variable period from HIV infection to the development of AIDS and the introduction of highly active antiretroviral therapy, accurate incidence estimation remains a major challenge. Numerous estimation methods have been proposed in epidemiological modeling studies, and here we review commonly-used methods for estimation of HIV incidence. We review the essential data required for estimation along with the advantages and disadvantages, mathematical structures and likelihood derivations of these methods. The methods include the classical back-calculation method, the method based on CD4+ T-cell depletion, the use of HIV case reporting data, the use of cohort study data, the use of serial or cross-sectional prevalence data, and biomarker approach. By outlining the mechanistic features of each method, we provide guidance for planning incidence estimation efforts, which may depend on national or regional factors as well as the availability of epidemiological or laboratory datasets.

HIV-Related Deaths in Nairobi, Kenya: Results From a HIV Mortuary Surveillance Study, 2015

BACKGROUND

Death is an important but often unmeasured endpoint in public health HIV surveillance. We sought to describe HIV among deaths using a novel mortuary-based approach in Nairobi, Kenya.

METHODS

Cadavers aged 15 years and older at death at Kenyatta National Hospital (KNH) and City Mortuaries were screened consecutively from January 29 to March 3, 2015. Cause of death was abstracted from medical files and death notification forms. Cardiac blood was drawn and tested for HIV infection using the national HIV testing algorithm followed by viral load testing of HIV-positive samples.

RESULTS

Of 807 eligible cadavers, 610 (75.6%) had an HIV test result available. Cadavers from KNH had significantly higher HIV positivity at 23.2% (95% CI: 19.3 to 27.7) compared with City Mortuary at 12.6% (95% CI: 8.8 to 17.8), P < 0.001. HIV prevalence was significantly higher among women than men at both City (33.3% vs. 9.2%, P = 0.008) and KNH Mortuary (28.8% vs. 19.0%, P = 0.025). Half (53.3%) of HIV-infected cadavers had no diagnosis before death, and an additional 22.2% were only diagnosed during hospitalization leading to death. Although not statistically significant, 61.9% of males had no previous diagnosis compared with 45.8% of females (P = 0.144). Half (52.3%) of 44 cadavers at KNH with HIV diagnosis before death were on treatment, and 1 in 5 (22.7%) with a previous diagnosis had achieved viral suppression.

CONCLUSIONS

HIV prevalence was high among deaths in Nairobi, especially among women, and previous diagnosis among cadavers was low. Establishing routine mortuary surveillance can contribute to monitoring HIV-associated deaths among cadavers sent to mortuaries.

Updates to the Spectrum/AIM model for estimating key HIV indicators at national and subnational levels

Supplemental Digital Content is available in the text

Background:

The Spectrum/AIM model is used by national programs and UNAIDS to prepare annual estimates of the status of the HIV epidemic in 170 countries. The model and assumptions are updated regularly under the guidance of the UNAIDS Reference Group on Estimates, Modelling and Projections in response to new data, studies and program needs. This article describes the most recent updates for the 2018 round of estimates.

Methods:

New data on AIDS-related mortality from Europe and Brazil have been used to update mortality rates of those not on antiretroviral therapy (ART). Household survey data and new studies of pregnant women, mothers, and children have been used to improve estimates of the number of HIV-positive pregnant and breastfeeding women and pediatric ART initiation. New tools to estimate geographic variation in HIV prevalence have been used to prepare district estimates of key indicators.

Results:

The 2018 version of Spectrum includes: new estimates of non-ART AIDS-related mortality by CD4⁺ count that depend on ART coverage; a procedure to estimate country-specific patterns of HIV incidence by age by fitting to prevalence by age from household surveys; an updated estimate of postpartum transmission with ART started before pregnancy of 0.023% per month; an updated estimate of retention on treatment at delivery of 80% for all women on ART; a somewhat older pattern of ART initiation by age that has 26% of new pediatric patients initiating ART at 10–14 years of age, 18% at 2–4 years of age, and 26% at 5–9 years of age; and a new tool for estimating key HIV indicators at the district level.

Conclusion:

The new methods and data implemented in the 2018 version of Spectrum allow national programs more flexibility in describing their programs and are intended to improve the estimates of adult mortality and pediatric HIV indicators.

Estimating and projecting the number of new HIV diagnoses and incidence in Spectrum's case surveillance and vital registration tool

Supplemental Digital Content is available in the text

Objective:

The Joint United Nations Programme on HIV/AIDS-supported Spectrum software package is used by most countries worldwide to monitor the HIV epidemic. In Spectrum, HIV incidence trends among adults (aged 15–49 years) are derived by either fitting to seroprevalence surveillance and survey data or generating curves consistent with case surveillance and vital registration data, such as historical trends in the number of newly diagnosed infections or AIDS-related deaths. This article describes development and application of the case surveillance and vital registration (CSAVR) tool for the 2019 estimate round.

Methods:

Incidence in CSAVR is either estimated directly using single logistic, double logistic, or spline functions, or indirectly via the ‘r-logistic’ model, which represents the (log-transformed) per-capita transmission rate using a logistic function. The propensity to get diagnosed is assumed to be monotonic, following a Gamma cumulative distribution function and proportional to mortality as a function of time since infection. Model parameters are estimated from a combination of historical surveillance data on newly reported HIV cases, mean CD4⁺ at HIV diagnosis and estimates of AIDS-related deaths from vital registration systems. Bayesian calibration is used to identify the best fitting incidence trend and uncertainty bounds.

Results:

We used CSAVR to estimate HIV incidence, number of new diagnoses, mean CD4⁺ at diagnosis and the proportion undiagnosed in 31 European, Latin American, Middle Eastern, and Asian-Pacific countries. The spline model appeared to provide the best fit in most countries (45%), followed by the r-logistic (25%), double logistic (25%), and single logistic models. The proportion of HIV-positive people who knew their status increased from about 0.31 [interquartile range (IQR): 0.10–0.45] in 1990 to about 0.77 (IQR: 0.50–0.89) in 2017. The mean CD4⁺ at diagnosis appeared to be stable, at around 410 cells/μl (IQR: 224–567) in 1990 and 373 cells/μl (IQR: 174–475) by 2017.

Conclusion:

Robust case surveillance and vital registration data are routinely available in many middle-income and high-income countries while HIV seroprevalence surveillance and survey data may be scarce. In these countries, CSAVR offers a simpler, improved approach to estimating and projecting trends in both HIV incidence and knowledge of HIV status.

Parameter estimates for trends and patterns of excess mortality among persons on antiretroviral therapy in high-income European settings

Supplemental Digital Content is available in the text

Introduction:

HIV cohort data from high-income European countries were compared with the UNAIDS Spectrum modelling parameters for these same countries to validate mortality rates and excess mortality estimates for people living with HIV (PLHIV) on antiretroviral therapy (ART).

Methods:

Data from 2000 to 2015 were analysed from the Antiretroviral Therapy Cohort Collaboration (ART-CC) for Austria, Denmark, France, Italy, the Netherlands, Spain, and Switzerland. Flexible parametric models were used to compare all-cause mortality rates in the ART-CC and Spectrum. The percentage of AIDS-related deaths and excess mortality (both are the same within Spectrum) were compared, with excess mortality defined as that in excess of the general population mortality.

Results:

Analyses included 94 026 PLHIV with 585 784 person-years of follow-up, from which there were 5515 deaths. All-cause annual mortality rates in Spectrum for 2000–2003 were 0.0121, reducing to 0.0078 in 2012–2015, whilst the ART-CC's corresponding annual mortality rates were 0.0151 [95% confidence interval (95% CI): 0.0130–0.0171] reducing to 0.0049 (95% CI: 0.0039–0.0060). The percentage of AIDS-related deaths in Spectrum was 74.7% in 2000–2003, dropping to 43.6% in 2012–2015. In the ART-CC, AIDS-related mortality constitutes 45.3% (95% CI: 38.4–52.9%) of mortality in 2000–2003 and 26.7% (95% CI: 19–46%) between 2012 and 2015. Excess mortality in the ART-CC was broadly similar to the Spectrum estimates, dropping from 75.3% (95% CI: 60.3–95.2%) in 2000–2003 to 30.7% (95% CI: 25.5–63.7%) in 2012–2015.

Conclusion:

All-cause mortality assumptions for PLHIV on ART in high-income European settings should be adjusted in Spectrum to be higher in 2000–2003 and decline more quickly to levels currently captured for recent years.

National and sub-national HIV/AIDS-related mortality in Iran, 1990-2015: a population-based modeling study

Surveillance of HIV/AIDS mortality is crucial to evaluate a country’s response to the disease. With a modified estimation approach, this study aimed to provide more accurate estimates on deaths due to HIV/AIDS in Iran from 1990 to 2015 at national and sub-national levels. Using a comprehensive data set, death registration incompleteness and misclassification were addressed by demographical and statistical methods. Trends of mortality due to HIV/AIDS at national and sub-national levels were estimated by applying a set of models. A total of 474 men (95% uncertainty interval [UI]: 175–1332) and 256 women (95% UI: 36–1871) died due to HIV/AIDS in 2015 in Iran. Peaked in 1995, HIV/AIDS-related mortality has steadily declined among both genders. Mortality rates were remarkably higher among men than women during the period studied. At the sub-national level, the highest and the lowest annual percent change were found at 10.97 and −1.36% for women, and 4.04 and −3.47% for men, respectively. The findings of our study (731 deaths) were remarkably lower than the Joint United Nations Programme on HIV and AIDS (4000) but higher than Global Burden of Disease (339) estimates in 2015. The overall decrease in mortality due to HIV/AIDS may be attributed to the increasing burden of noncommunicable diseases; however, the role of the national and international organizations to fight HIV/AIDS should not be overlooked. To decrease HIV/AIDS mortality and to achieve international goals, evidence-based action is required. To fast-track targets, the priority must be to prevent infection, promote early diagnosis, provide access to treatment, and to ensure treatment adherence among patients.

Cost and Cost-Effectiveness of a Demand Creation Intervention to Increase Uptake of Voluntary Medical Male Circumcision in Tanzania: Spending More to Spend Less

Supplemental Digital Content is Available in the Text.

Background:

Although voluntary medical male circumcision (VMMC) reduces the risk of HIV acquisition, demand for services is lower among men in most at-risk age groups (ages 20–34 years). A randomized controlled trial was conducted to assess the effectiveness of locally-tailored demand creation activities (including mass media, community mobilization, and targeted service delivery) in increasing uptake of campaign-delivered VMMC among men aged 20–34 years. We conducted an economic evaluation to understand the intervention's cost and cost-effectiveness.

Setting:

Tanzania (Njombe and Tabora regions).

Methods:

Cost data were collected on surgery, demand creation activities, and monitoring and supervision related to VMMC implementation across clusters in both trial arms, as well as start-up activities for the intervention arms. The Decision Makers' Program Planning Tool was used to estimate the number of HIV infections averted and related cost savings, given the total VMMCs per cluster. Disability-adjusted life years were calculated and used to estimate incremental cost-effectiveness ratios.

Results:

Client load was higher in the intervention arms than in the control arms: 4394 vs. 2901 in Tabora and 1797 vs. 1025 in Njombe, respectively. Despite additional costs of tailored demand creation, demand increased more than proportionally: mean costs per VMMC in the intervention arms were $62 in Tabora and $130 in Njombe, and in the control arms $70 and $191, respectively. More infections were averted in the intervention arm than in the control arm in Tabora (123 vs. 67, respectively) and in Njombe (164 vs. 102, respectively). The intervention dominated the control because it was both less costly and more effective. Cost savings were observed in both regions stemming from the antiretroviral treatment costs averted as a result of the VMMCs performed.

Conclusions:

Spending more to address local preferences as a way to increase uptake of VMMC can be cost-saving.

Additional resource needs for viral hepatitis elimination through universal health coverage: projections in 67 low-income and middle-income countries, 2016-30

BACKGROUND

The World Health Assembly calls for elimination of viral hepatitis as a public health threat by 2030 (ie, -90% incidence and -65% mortality). However, WHO's 2017 cost projections to achieve health-related Sustainable Development Goals did not include the resources needed for hepatitis testing and treatment. We aimed to estimate the incremental commodity cost of adding scaled up interventions for testing and treatment of hepatitis to WHO's investment scenarios.

METHODS

We added modelled costs for implementing WHO recommended hepatitis testing and treatment to the 2017 WHO cost projections. We quantified additional requirements for diagnostic tests, medicines, health workers' time, and programme support across 67 low-income and middle-income countries, from 2016-30. A progress scenario scaled up interventions and a more ambitious scenario was modelled to reach elimination by 2030. We used 2018 best available prices of diagnostics and generic medicines. We estimated total costs and the additional investment needed over the projection of the 2016 baseline cost.

FINDINGS

The 67 countries considered included 230 million people living with hepatitis B virus (HBV) and 52 million people living with hepatitis C virus (HCV; 90% and 73% of the world's total, respectively). Under the progress scenario, 3250 million people (2400 million for HBV and 850 million for HCV) would be tested and 58·2 million people (24·1 million for HBV and 34·1 million for HCV) would be treated (total additional cost US$ 27·1 billion). Under the ambitious scenario, 11 631 million people (5502 million for HBV and 6129 million for HCV) would be tested and 93·8 million people (32·2 million for HBV and 61·6 million for HCV) would be treated (total additional cost $58·7 billion), averting 4·5 million premature deaths and leading to a gain of 51·5 million healthy life-years by 2030. However, if affordable HCV medicines remained inaccessible in 13 countries where medicine patents are protected, the additional cost of the ambitious scenario would increase to $118 billion. Hepatitis elimination would account for a 1·5% increase to the WHO ambitious health-care strengthening scenario costs, avert an additional 4·6% premature deaths, and add an additional 9·6% healthy life-years from 2016-30.

INTERPRETATION

Access to affordable medicines in all countries will be key to reach hepatitis elimination. This study suggests that elimination is feasible in the context of universal health coverage. It points to commodities as key determinants for the overall price tag and to options for cost reduction strategies.

FUNDING

WHO, United States Centers for Disease Control and Prevention, Unitaid.

HIV, syphilis and hepatitis B coinfections in Mkushi, Zambia: a cross-sectional study

ABSTRACTBackground: Human Immunodeficiency Virus, syphilis and Hepatitis B Virus are major global public health problems, they are sexually transmitted infections with overlapping modes of transmission and affected populations.  Objective: The aim of this study is to assess the seroprevalence of HIV 1, hepatitis B virus and syphilis coinfections among newly diagnosed HIV individuals aged 16 to 65 years, initiating on antiretroviral therapy, in Mkushi, Zambia. Methods: A total number of 126 sera were collected from HIV 1 infected patients attending Mkushi district hospital/ART clinic for antiretroviral therapy initiation. Hepatitis B surface antigen test and serologic test for syphilis were conducted between March and May 2018. Results: Of the 126 participants (out of 131 enrollments), Hepatitis B surface antigen (HBsAg) was detected with a prevalence of 9.5% among newly diagnosed HIV infected patients, while that of syphilis was as high as 40.5% in this same population group. Three patients recorded HIV coinfections with both syphilis and hepatitis B virus (2.4%) at the same time. After analysis, the results indicate that there was no significant association between gender for both dependent variables: HIV/syphilis or HIV/hepatitis B virus coinfections (alpha significance level > 0.05). Those who had a history of syphilis infection in the past were more likely than those who had none to be HIV-syphilis coinfected (53.6% vs 34%, respectively; odd ratio [OR] 2.236; 95% confidence interval [CI] 1.045 - 4.782). Conclusion: The high prevalence rates for HIV, HBV, and syphilis coinfections strongly indicate the need for HBV and syphilis screening for HIV infected individuals. Furthermore, the high number of patients previously treated for syphilis who retest positive for syphilis in this study calls for use of the Venereal Disease Research Laboratory test to identify true syphilis infection (titers ≥ 1:8 dilutions, strongly suggestive).

HIV, syphilis and hepatitis B coinfections in Mkushi, Zambia: a cross-sectional study

Background: Human immunodeficiency virus, syphilis and hepatitis B virus (HBV) are major global public health problems. They are sexually transmitted diseases with overlapping modes of transmission and affected populations. The aim of this study is to assess the seroprevalence of HIV 1, hepatitis B virus and syphilis coinfections among newly diagnosed HIV individuals aged 16 to 65 years, initiating on antiretroviral therapy, in Mkushi, Zambia. Methods: A total number of 126 sera were collected from HIV 1 infected patients attending Mkushi district hospital/ART clinic for antiretroviral therapy initiation. Hepatitis B surface antigen test and serologic test for syphilis were conducted between March and May 2018. Results: Of the 126 participants, hepatitis B surface antigen (HBsAg) was detected with a prevalence of 9.5% among newly diagnosed HIV infected patients, while that of syphilis was as high as 40.5% in this same population group. Three patients recorded HIV coinfections with both syphilis and hepatitis B virus (2.4%) at the same time. After analysis, the results indicate that there was no significant association between gender for both dependent variables: HIV/syphilis or HIV/hepatitis B virus coinfections (alpha significance level > 0.05). Those who had a history of syphilis infection in the past were more likely than those who had none to be HIV-syphilis coinfected (53.6% vs 34%, respectively; odd ratio [OR] 2.236; 95% confidence interval [CI] 1.045 - 4.782). Conclusion: The high prevalence rates for HIV, HBV, and syphilis coinfections strongly indicate the need for HBV and syphilis screening for HIV infected individuals. Furthermore, the high number of patients previously treated for syphilis who retest positive for syphilis in this study calls for use of the Venereal Disease Research Laboratory test to identify true syphilis infection (titers ≥ 1:8 dilutions, strongly suggestive).

Challenges in modelling the proportion of undiagnosed HIV infections in Sweden

BackgroundSweden has a low HIV prevalence. However, among new HIV diagnoses in 2016, the proportion of late presenters and migrants was high (59% and 81%, respectively). This poses challenges in estimating the proportion of undiagnosed persons living with HIV (PLHIV).AimTo estimate the proportion of undiagnosed PLHIV in Sweden comparing two models with different demands on data availability and modelling expertise.MethodsAn individual-based stochastic simulation model of HIV positive populations (SSOPHIE) and the incidence method of the European Centre for Disease Prevention and Control (ECDC) HIV Modelling Tool were applied to clinical, surveillance and migration data from Sweden 1980-2016.ResultsSSOPHIE estimated that the proportion of undiagnosed PLHIV in 2013 was 26% (n = 2,100; 90% plausibility range (PR): 900-5,000) for all PLHIV, 17% (n = 600; 90% PR: 100-2,000) for men who have sex with men (MSM), 35% in male (n = 300; 90% PR: 200-700) and 34% in female (n = 400; 90% PR: 200-800) migrants from sub-Saharan Africa (SSA). The estimates for the ECDC model in 2013 were 21% (n = 2,013; 95% confidence interval (CI): 1,831-2,189) for all PLHIV, 15% (n = 369; 95% CI: 299-434) for MSM and 21% (n = 530; 95% CI: 436-632) for migrants from SSA.ConclusionsThe proportion of undiagnosed PLHIV in Sweden is uncertain. SSOPHIE estimates had wide PR. The ECDC model estimates were unreliable because migration was not accounted for. Better migration data and estimation methods are required to obtain reliable estimates of proportions of undiagnosed PLHIV in similar settings.

Global and regional trends of people living with HIV aged 50 and over: Estimates and projections for 2000-2020

BACKGROUND

The increasing numbers of people living with HIV (PLHIV) who are receiving antiretroviral therapy (ART) have near normal life-expectancy, resulting in more people living with HIV over the age of 50 years (PLHIV50+). Estimates of the number of PLHIV50+ are needed for the development of tailored therapeutic and prevention interventions at country, regional and global level.

METHODS

The AIDS Impact Module of the Spectrum software was used to compute the numbers of PLHIV, new infections, and AIDS-related deaths for PLHIV50+ for the years 2000-2016. Projections until 2020 were calculated based on an assumed ART scale-up to 81% coverage by 2020, consistent with the UNAIDS 90-90-90 treatment targets.

RESULTS

Globally, there were 5.7 million [4.7 million- 6.6 million] PLHIV50+ in 2016. The proportion of PLHIV50+ increased substantially from 8% in 2000 to 16% in 2016 and is expected to increase to 21% by 2020. In 2016, 80% of PLHIV50+ lived in low- and middle-income countries (LMICs), with Eastern and Southern Africa containing the largest number of PLHIV50+. While the proportion of PLHIV50+ was greater in high income countries, LMICs have higher numbers of PLHIV50+ that are expected to continue to increase by 2020.

CONCLUSIONS

The number of PLHIV50+ has increased dramatically since 2000 and this is expected to continue by 2020, especially in LMICs. HIV prevention campaigns, testing and treatment programs should also focus on the specific needs of PLHIV50+. Integrated health and social services should be developed to cater for the changing physical, psychological and social needs of PLHIV50+, many of whom will need to use HIV and non-HIV services.

Forecasting life expectancy, years of life lost, and all-cause and cause-specific mortality for 250 causes of death: reference and alternative scenarios for 2016-40 for 195 countries and territories

BACKGROUND

Understanding potential trajectories in health and drivers of health is crucial to guiding long-term investments and policy implementation. Past work on forecasting has provided an incomplete landscape of future health scenarios, highlighting a need for a more robust modelling platform from which policy options and potential health trajectories can be assessed. This study provides a novel approach to modelling life expectancy, all-cause mortality and cause of death forecasts -and alternative future scenarios-for 250 causes of death from 2016 to 2040 in 195 countries and territories.

METHODS

We modelled 250 causes and cause groups organised by the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) hierarchical cause structure, using GBD 2016 estimates from 1990-2016, to generate predictions for 2017-40. Our modelling framework used data from the GBD 2016 study to systematically account for the relationships between risk factors and health outcomes for 79 independent drivers of health. We developed a three-component model of cause-specific mortality: a component due to changes in risk factors and select interventions; the underlying mortality rate for each cause that is a function of income per capita, educational attainment, and total fertility rate under 25 years and time; and an autoregressive integrated moving average model for unexplained changes correlated with time. We assessed the performance by fitting models with data from 1990-2006 and using these to forecast for 2007-16. Our final model used for generating forecasts and alternative scenarios was fitted to data from 1990-2016. We used this model for 195 countries and territories to generate a reference scenario or forecast through 2040 for each measure by location. Additionally, we generated better health and worse health scenarios based on the 85th and 15th percentiles, respectively, of annualised rates of change across location-years for all the GBD risk factors, income per person, educational attainment, select intervention coverage, and total fertility rate under 25 years in the past. We used the model to generate all-cause age-sex specific mortality, life expectancy, and years of life lost (YLLs) for 250 causes. Scenarios for fertility were also generated and used in a cohort component model to generate population scenarios. For each reference forecast, better health, and worse health scenarios, we generated estimates of mortality and YLLs attributable to each risk factor in the future.

FINDINGS

Globally, most independent drivers of health were forecast to improve by 2040, but 36 were forecast to worsen. As shown by the better health scenarios, greater progress might be possible, yet for some drivers such as high body-mass index (BMI), their toll will rise in the absence of intervention. We forecasted global life expectancy to increase by 4·4 years (95% UI 2·2 to 6·4) for men and 4·4 years (2·1 to 6·4) for women by 2040, but based on better and worse health scenarios, trajectories could range from a gain of 7·8 years (5·9 to 9·8) to a non-significant loss of 0·4 years (-2·8 to 2·2) for men, and an increase of 7·2 years (5·3 to 9·1) to essentially no change (0·1 years [-2·7 to 2·5]) for women. In 2040, Japan, Singapore, Spain, and Switzerland had a forecasted life expectancy exceeding 85 years for both sexes, and 59 countries including China were projected to surpass a life expectancy of 80 years by 2040. At the same time, Central African Republic, Lesotho, Somalia, and Zimbabwe had projected life expectancies below 65 years in 2040, indicating global disparities in survival are likely to persist if current trends hold. Forecasted YLLs showed a rising toll from several non-communicable diseases (NCDs), partly driven by population growth and ageing. Differences between the reference forecast and alternative scenarios were most striking for HIV/AIDS, for which a potential increase of 120·2% (95% UI 67·2-190·3) in YLLs (nearly 118 million) was projected globally from 2016-40 under the worse health scenario. Compared with 2016, NCDs were forecast to account for a greater proportion of YLLs in all GBD regions by 2040 (67·3% of YLLs [95% UI 61·9-72·3] globally); nonetheless, in many lower-income countries, communicable, maternal, neonatal, and nutritional (CMNN) diseases still accounted for a large share of YLLs in 2040 (eg, 53·5% of YLLs [95% UI 48·3-58·5] in Sub-Saharan Africa). There were large gaps for many health risks between the reference forecast and better health scenario for attributable YLLs. In most countries, metabolic risks amenable to health care (eg, high blood pressure and high plasma fasting glucose) and risks best targeted by population-level or intersectoral interventions (eg, tobacco, high BMI, and ambient particulate matter pollution) had some of the largest differences between reference and better health scenarios. The main exception was sub-Saharan Africa, where many risks associated with poverty and lower levels of development (eg, unsafe water and sanitation, household air pollution, and child malnutrition) were projected to still account for substantive disparities between reference and better health scenarios in 2040.

INTERPRETATION

With the present study, we provide a robust, flexible forecasting platform from which reference forecasts and alternative health scenarios can be explored in relation to a wide range of independent drivers of health. Our reference forecast points to overall improvements through 2040 in most countries, yet the range found across better and worse health scenarios renders a precarious vision of the future-a world with accelerating progress from technical innovation but with the potential for worsening health outcomes in the absence of deliberate policy action. For some causes of YLLs, large differences between the reference forecast and alternative scenarios reflect the opportunity to accelerate gains if countries move their trajectories toward better health scenarios-or alarming challenges if countries fall behind their reference forecasts. Generally, decision makers should plan for the likely continued shift toward NCDs and target resources toward the modifiable risks that drive substantial premature mortality. If such modifiable risks are prioritised today, there is opportunity to reduce avoidable mortality in the future. However, CMNN causes and related risks will remain the predominant health priority among lower-income countries. Based on our 2040 worse health scenario, there is a real risk of HIV mortality rebounding if countries lose momentum against the HIV epidemic, jeopardising decades of progress against the disease. Continued technical innovation and increased health spending, including development assistance for health targeted to the world's poorest people, are likely to remain vital components to charting a future where all populations can live full, healthy lives.

FUNDING

Bill & Melinda Gates Foundation.

Bringing Real-Time Geospatial Precision to HIV Surveillance Through Smartphones: Feasibility Study

BACKGROUND

Precise measurements of HIV incidences at community level can help mount a more effective public health response, but the most reliable methods currently require labor-intensive population surveys. Novel mobile phone technologies are being tested for adherence to medical appointments and antiretroviral therapy, but using them to track HIV test results with automatically generated geospatial coordinates has not been widely tested.

OBJECTIVE

We customized a portable reader for interpreting the results of HIV lateral flow tests and developed a mobile phone app to track HIV test results in urban and rural locations in Rwanda. The objective was to assess the feasibility of this technology to collect front line HIV test results in real time and with geospatial context to help measure HIV incidences and improve epidemiological surveillance.

METHODS

Twenty health care workers used the technology to track the test results of 2190 patients across 3 hospital sites (2 urban sites in Kigali and a rural site in the Western Province of Rwanda). Mobile phones for less than US $70 each were used. The mobile phone app to record HIV test results could take place without internet connectivity with uploading of results to the cloud taking place later with internet.

RESULTS

A total of 91.51% (2004/2190) of HIV test results could be tracked in real time on an online dashboard with geographical resolution down to street level. Out of the 20 health care workers, 14 (70%) would recommend the lateral flow reader, and 100% would recommend the mobile phone app.

CONCLUSIONS

Smartphones have the potential to simplify the input of HIV test results with geospatial context and in real time to improve public health surveillance of HIV.

Sustained progress, but no room for complacency: Results of 2015 HIV estimations in India

Background & objectives:

Evidence-based planning has been the cornerstone of India's response to HIV/AIDS. Here we describe the process, method and tools used for generating the 2015 HIV estimates and provide a summary of the main results.

Methods:

Spectrum software supported by the UNAIDS was used to produce HIV estimates for India as a whole and its States/Union Territories. This tool takes into consideration the size and HIV prevalence of defined population groups and programme data to estimate HIV prevalence, incidence and mortality over time as well as treatment needs.

Results:

India's national adult prevalence of HIV was 0.26 per cent in 2015. Of the 2.1 million people living with HIV/AIDS, the largest numbers were in Andhra Pradesh, Maharashtra and Karnataka. New HIV infections were an estimated 86,000 in 2015, reflecting a decline by around 32 per cent from 2007. The declining trend in incidence was mirrored in most States, though an increasing trend was detected in Assam, Chandigarh, Chhattisgarh, Gujarat, Sikkim, Tripura and Uttar Pradesh. AIDS-related deaths were estimated to be 67,600 in 2015, reflecting a 54 per cent decline from 2007. There were variations in the rate and trend of decline across India for this indicator also.

Interpretation & conclusions:

While key indicators measured through Spectrum modelling confirm success of the National AIDS Control Programme, there is no room for complacency as rising incidence trends in some geographical areas and population pockets remain the cause of concern. Progress achieved so far in responding to HIV/AIDS needs to be sustained to end the HIV epidemic.

Trends in HIV/AIDS morbidity and mortality in Eastern Mediterranean countries, 1990-2015: findings from the Global Burden of Disease 2015 study

OBJECTIVES

We used the results of the Global Burden of Disease 2015 study to estimate trends of HIV/AIDS burden in Eastern Mediterranean Region (EMR) countries between 1990 and 2015.

METHODS

Tailored estimation methods were used to produce final estimates of mortality. Years of life lost (YLLs) were calculated by multiplying the mortality rate by population by age-specific life expectancy. Years lived with disability (YLDs) were computed as the prevalence of a sequela multiplied by its disability weight.

RESULTS

In 2015, the rate of HIV/AIDS deaths in the EMR was 1.8 (1.4-2.5) per 100,000 population, a 43% increase from 1990 (0.3; 0.2-0.8). Consequently, the rate of YLLs due to HIV/AIDS increased from 15.3 (7.6-36.2) per 100,000 in 1990 to 81.9 (65.3-114.4) in 2015. The rate of YLDs increased from 1.3 (0.6-3.1) in 1990 to 4.4 (2.7-6.6) in 2015.

CONCLUSIONS

HIV/AIDS morbidity and mortality increased in the EMR since 1990. To reverse this trend and achieve epidemic control, EMR countries should strengthen HIV surveillance, and scale up HIV antiretroviral therapy and comprehensive prevention services.

HIV incidence in western Kenya during scale-up of antiretroviral therapy and voluntary medical male circumcision: a population-based cohort analysis

BACKGROUND

In Kenya, coverage of antiretroviral therapy (ART) among people with HIV infection has increased from 7% in 2006, to 57% in 2016; and, in western Kenya, coverage of voluntary medical male circumcision (VMMC) increased from 45% in 2008, to 72% in 2014. We investigated trends in HIV prevalence and incidence in a high burden area in western Kenya in 2011-16.

METHODS

In 2011, 2012, and 2016, population-based surveys were done via a health and demographic surveillance system and home-based counselling and testing in Gem, Siaya County, Kenya, including 28 688, 17 021, and 16 772 individuals aged 15-64 years. Data on demographic variables, self-reported HIV status, and risk factors were collected. Rapid HIV testing was offered to survey participants. Participants were tracked between surveys by use of health and demographic surveillance system identification numbers. HIV prevalence was calculated as a proportion, and HIV incidence was expressed as number of new infections per 1000 person-years of follow-up.

FINDINGS

HIV prevalence was stable in participants aged 15-64 years: 15% (4300/28 532) in 2011, 12% (2051/16 875) in 2012, and 15% (2312/15 626) in 2016. Crude prevalences in participants aged 15-34 years were 11% (1893/17 197) in 2011, 10% (1015/10 118) in 2012, and 9% (848/9125) in 2016; adjusted for age and sex these prevalences were 11%, 9%, and 8%. 12 606 (41%) of the 30 520 non-HIV-infected individuals enrolled were seen again in at least one more survey round, and were included in the analysis of HIV incidence. HIV incidence was 11·1 (95% CI 9·1-13·1) per 1000 person-years from 2011 to 2012, and 5·7 (4·6-6·9) per 1000 person-years from 2012 to 2016.

INTERPRETATION

With increasing coverage of ART and VMMC, HIV incidence declined substantially in Siaya County between 2011 and 2016. VMMC, but not ART, was suggested to have a direct protective effect, presumably because ART tended to be given to individuals with advanced HIV infection. HIV incidence is still high and not close to the elimination target of one per 1000 person-years. The effect of further scale-up of ART and VMMC needs to be monitored.

FUNDING

Data were collected under Cooperative Agreements with the US Centers for Disease Control and Prevention, with funding from the President's Emergency Fund for AIDS Relief.

A Two-Step Markov Processes Approach for Parameterization of Cancer State-Transition Models for Low- and Middle-Income Countries

Implementation of organized cancer screening and prevention programs in high-income countries (HICs) has considerably decreased cancer-related incidence and mortality. In low- and middle-income countries (LMICs), screening and early diagnosis programs are generally unavailable, and most cancers are diagnosed in late stages when survival is very low. Analyzing the cost-effectiveness of alternative cancer control programs and estimating resource needs will help prioritize interventions in LMICs. However, mathematical models of natural cancer onset and progression needed to conduct the economic analyses are predominantly based on populations in HICs because the longitudinal data on screening and diagnoses required for parameterization are unavailable in LMICs. Models currently used for LMICs mostly concentrate on directly calculating the shift in distribution of cancer diagnosis as an evaluative measure of screening. We present a mathematical methodology for the parameterization of natural cancer onset and progression, specifically for LMICs that do not have longitudinal data. This full onset and progression model can help conduct comprehensive analyses of cancer control programs, including cancer screening, by considering both the positive impact of screening as well as any adverse consequences, such as over-diagnosis and false-positive results. The methodology has been applied to breast, cervical, and colorectal cancers for 2 regions, under the World Health Organization categorization: Eastern Sub-Saharan Africa (AFRE) and Southeast Asia (SEARB). The cancer models have been incorporated into the Spectrum software and interfaced with country-specific demographic data through the demographic projections (DemProj) module and costing data through the OneHealth tool. These software are open-access and can be used by stakeholders to analyze screening strategies specific to their country of interest.

Modelling the human immunodeficiency virus (HIV) epidemic: A review of the substance and role of models in South Africa

We review key mathematical models of the South African human immunodeficiency virus (HIV) epidemic from the early 1990s onwards. In our descriptions, we sometimes differentiate between the concepts of a model world and its mathematical or computational implementation. The model world is the conceptual realm in which we explicitly declare the rules – usually some simplification of ‘real world’ processes as we understand them. Computing details of informative scenarios in these model worlds is a task requiring specialist knowledge, but all other aspects of the modelling process, from describing the model world to identifying the scenarios and interpreting model outputs, should be understandable to anyone with an interest in the epidemic.

Treatment of HIV for the Prevention of Transmission in Discordant Couples and at the Population Level

The scientific breakthrough proving that antiretroviral therapy (ART) can halt heterosexual HIV transmission came in the form of a landmark clinical trial conducted among serodiscordant couples. Study findings immediately informed global recommendations for the use of treatment as prevention in serodiscordant couples. The extent to which these findings are generalizable to other key populations or to groups exposed to HIV through nonsexual transmission routes (i.e., anal intercourse or unsafe injection of drugs) has since driven a large body of research. This review explores the history of HIV research in serodiscordant couples, the implications for management of couples, subsequent research on treatment as prevention in other key populations, and challenges in community implementation of these strategies.

Documenting and explaining the HIV decline in east Zimbabwe: the Manicaland General Population Cohort

PURPOSE

The Manicaland cohort was established to provide robust scientific data on HIV prevalence and incidence, patterns of sexual risk behaviour and the demographic impact of HIV in a sub-Saharan African population subject to a generalised HIV epidemic. The aims were later broadened to include provision of data on the coverage and effectiveness of national HIV control programmes including antiretroviral therapy (ART).

PARTICIPANTS

General population open cohort located in 12 sites in Manicaland, east Zimbabwe, representing 4 major socioeconomic strata (small towns, agricultural estates, roadside settlements and subsistence farming areas). 9,109 of 11,453 (79.5%) eligible adults (men 17-54 years; women 15-44 years) were recruited in a phased household census between July 1998 and January 2000. Five rounds of follow-up of the prospective household census and the open cohort were conducted at 2-year or 3-year intervals between July 2001 and November 2013. Follow-up rates among surviving residents ranged between 77.0% (over 3 years) and 96.4% (2 years).

FINDINGS TO DATE

HIV prevalence was 25.1% at baseline and had a substantial demographic impact with 10-fold higher mortality in HIV-infected adults than in uninfected adults and a reduction in the growth rate in the worst affected areas (towns) from 2.9% to 1.0%pa. HIV infection rates have been highest in young adults with earlier commencement of sexual activity and in those with older sexual partners and larger numbers of lifetime partners. HIV prevalence has since fallen to 15.8% and HIV incidence has also declined from 2.1% (1998-2003) to 0.63% (2009-2013) largely due to reduced sexual risk behaviour. HIV-associated mortality fell substantially after 2009 with increased availability of ART.

FUTURE PLANS

We plan to extend the cohort to measure the effects on the epidemic of current and future HIV prevention and treatment programmes. Proposals for access to these data and for collaboration are welcome.

Survival of HIV-1 vertically infected children

PURPOSE OF REVIEW

It is 20 years since the start of the combination antiretroviral therapy (cART) era and more than 10 years since cART scale-up began in resource-limited settings. We examined survival of vertically HIV-infected infants and children in the cART era.

RECENT FINDINGS

Good survival has been achieved on cART in all settings with up to 10-fold mortality reductions compared with before cART availability. Although mortality risk remains high in the first few months after cART initiation in young children with severe disease, it drops rapidly thereafter even for those who started with advanced disease, and longer term mortality risk is low. However, suboptimal retention on cART in routine programs threatens good survival outcomes and even on treatment children continue to experience high comorbidity risk; infections remain the major cause of death. Interventions to address infection risk include a cotrimoxazole prophylaxis, isoniazid preventive therapy, routine childhood and influenza immunization, and improving maternal survival.

SUMMARY

Pediatric survival has improved substantially with cART and HIV-infected children are aging into adulthood. It is important to ensure access to diagnosis and early cART, good program retention as well as optimal comorbidity prophylaxis and treatment to achieve the best possible long-term survival and health outcomes for vertically infected children.

Household survey of HIV incidence in Rwanda: a national observational cohort study

BACKGROUND

In Rwanda, HIV prevalence among adults aged 15-49 years has been stable at 3% since 2005. The aim of this study was to characterise HIV incidence across Rwanda.

METHODS

We did a nationally representative, prospective HIV incidence survey for the period of 2013-14, which used two-stage sampling. We randomly selected 492 villages in the first sampling stage and 14 households per village in the second stage. Participants completed a questionnaire and 14 140 people were tested for HIV. 13 728 participants were HIV negative, and were enrolled in the incidence cohort. Participants were retested and surveyed again after 12 months. Weights were calculated as the inverse of the probability to select the villages and the households.

FINDINGS

The study period was from Nov 5, 2013, to Nov 15, 2014. Among 14 222 respondents from 6792 households, 14 140 were tested for HIV and 13 728 were HIV negative. Of 12 593 people who participated in the endpoint data collection activities, 5965 (47·4%) were men and the mean age was 30 years (SD 10·8). 11 237 (89·2%) participants lived in rural areas, 4826 (38·3%) were single, and 7140 (56·7%) were married or cohabitating. During the year, 35 participants had seroconversion, including 13 men and 22 women, resulting in an overall incidence of 0·27 per 100 person-years (95% CI 0·18-0·35). Incidence was 0·21 per 100 person-years (0·10-0·32) in men and 0·32 per 100 person-years (0·19-0·45) in women. Our findings suggested multiple breakouts, with multiple seroconversions occurring in three villages and two households. Incidence was higher in adults aged 36-45 years (0·37 per 100 person-years, 0·12-0·62; adjusted hazard ratio [aHR] 4·49, 95% CI 1·30-14·70) relative to those aged 16-25, higher in western province (0·57 per 100 person-years, 0·31-0·87; aHR 5·90, 1·33-25·28) relative to the northern province, and higher in urban areas (0·65 per 100 person-years, 0·23-1·07; aHR 3·10, 1·28-6·99) than in rural areas.

INTERPRETATION

The incidence of HIV in Rwanda was higher than that previously estimated from models, with outbreaks seeming to contribute to the ongoing epidemic. Characterisation of incident infections can help the national HIV programmes to plan for preventive interventions tailored to the most at risk populations.

FUNDING

Global Fund to Fight HIV, Tuberculosis and Malaria, WHO Rwanda, UNAIDS Rwanda, and the Government of Rwanda.

HIV-associated mortality in the era of antiretroviral therapy scale-up - Nairobi, Kenya, 2015

Background

Declines in HIV prevalence and increases in antiretroviral treatment coverage have been documented in Kenya, but population-level mortality associated with HIV has not been directly measured. In urban areas where a majority of deaths pass through mortuaries, mortuary-based studies have the potential to contribute to our understanding of excess mortality among HIV-infected persons. We used results from a cross-sectional mortuary-based HIV surveillance study to estimate the association between HIV and mortality for Nairobi, the capital city of Kenya.

Methods and findings

HIV seropositivity in cadavers measured at the two largest mortuaries in Nairobi was used to estimate HIV prevalence in adult deaths. Model-based estimates of the HIV-infected and uninfected population for Nairobi were used to calculate a standardized mortality ratio and population-attributable fraction for mortality among the infected versus uninfected population. Monte Carlo simulation was used to assess sensitivity to epidemiological assumptions. When standardized to the age and sex distribution of expected deaths, the estimated HIV positivity among adult deaths aged 15 years and above in Nairobi was 20.9% (95% CI 17.7–24.6%). The standardized mortality ratio of deaths among HIV-infected versus uninfected adults was 4.35 (95% CI 3.67–5.15), while the risk difference was 0.016 (95% CI 0.013–0.019). The HIV population attributable mortality fraction was 0.161 (95% CI 0.131–0.190). Sensitivity analyses demonstrated robustness of results.

Conclusions

Although 73.6% of adult PLHIV receive antiretrovirals in Nairobi, their risk of death is four-fold greater than in the uninfected, while 16.1% of all adult deaths in the city can be attributed to HIV infection. In order to further reduce HIV-associated mortality, high-burden countries may need to reach very high levels of diagnosis, treatment coverage, retention in care, and viral suppression.

Joint estimation of CD4+ cell progression and survival in untreated individuals with HIV-1 infection

OBJECTIVE

We compiled the largest dataset of seroconverter cohorts to date from 25 countries across Africa, North America, Europe, and Southeast/East (SE/E) Asia to simultaneously estimate transition rates between CD4 cell stages and death, in antiretroviral therapy (ART)-naive HIV-1-infected individuals.

DESIGN

A hidden Markov model incorporating a misclassification matrix was used to represent natural short-term fluctuations and measurement errors in CD4 cell counts. Covariates were included to estimate the transition rates and survival probabilities for each subgroup.

RESULTS

The median follow-up time for 16 373 eligible individuals was 4.1 years (interquartile range 1.7-7.1), and the mean age at seroconversion was 31.1 years (SD 8.8). A total of 14 525 individuals had recorded CD4 cell counts pre-ART, 1885 died, and 6947 initiated ART. Median (interquartile range) survival for men aged 20 years at seroconversion was 13.0 (12.4-13.4), 11.6 (10.9-12.3), and 8.3 years (7.9-8.9) in Europe/North America, Africa, and SE/E Asia, respectively. Mortality rates increase with age (hazard ratio 2.22, 95% confidence interval 1.84-2.67 for >45 years compared with <25 years) and vary by region (hazard ratio 2.68, 1.75-4.12 for Africa and 1.88, 1.50-2.35 for Asia compared with Europe/North America). CD4 cell decline was significantly faster in Asian cohorts compared with Europe/North America (hazard ratio 1.45, 1.36-1.54).

CONCLUSION

Mortality and CD4 cell progression rates exhibited regional and age-specific differences, with decreased survival in African and SE/E Asian cohorts compared with Europe/North America and in older age groups. This extensive dataset reveals heterogeneities between regions and ages, which should be incorporated into future HIV models.

Diagnosis of viral hepatitis

PURPOSE OF REVIEW

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and HIV-HBV and HCV coinfection are major causes of chronic liver disease worldwide. Testing and diagnosis is the gateway for access to both treatment and prevention services, but there remains a large burden of undiagnosed infection globally. We review the global epidemiology, key challenges in the current hepatitis testing response, new tools to support the hepatitis global response (2016-2020 Global Hepatitis Health Sector strategy, and 2017 WHO guidelines on hepatitis testing) and future directions and innovations in hepatitis diagnostics.

RECENT FINDINGS

Key challenges in the current hepatitis testing response include lack of quality-assured serological and low-cost virological in-vitro diagnostics, limited facilities for testing, inadequate data to guide country-specific hepatitis testing approaches, stigmatization of those with or at risk of viral hepatitis and lack of guidelines on hepatitis testing for resource-limited settings. The new Global Hepatitis Health Sector strategy sets out goals for elimination of viral hepatitis as a public health threat by 2030 and gives outcome targets for reductions in new infections and mortality, as well as service delivery targets that include testing, diagnosis and treatment. The 2017 WHO hepatitis testing guidelines for adults, adolescents and children in low-income and middle-income countries outline the public health approach to strengthen and expand current testing practices for viral hepatitis and addresses who to test (testing approaches), which serological and virological assays to use (testing strategies) as well as interventions to promote linkage to prevention and care.

SUMMARY

Future directions and innovations in hepatitis testing include strategies to improve access such as through use of existing facility and community-based testing opportunities for hepatitis testing, near-patient or point-of-care assays for virological markers (nucleic acid testing and HCV core antigen), dried blood spot specimens used with different serological and nucleic acid test assays, multiplex and multi-disease platforms to enable testing for multiple analytes/pathogens and potential self-testing for viral hepatitis.

Updates to the Spectrum/Estimations and Projections Package model for estimating trends and current values for key HIV indicators

BACKGROUND

The Spectrum model is used by national programs and UNAIDS to prepare annual estimates of the status of the HIV epidemic in 160 countries. The model and assumptions are updated regularly under the guidance of the UNAIDS Reference Group on Estimates, Modelling and Projections in response to new data, studies, and program needs. This study describes the most recent updates for the 2016 round of estimates.

METHODS

Meetings of the UNAIDS Reference Group include individuals with extensive knowledge of HIV programs, research, statistics, and public policy. The Reference Group also collaborates with other institutions (such as the United Nations Population Division and the US Census Bureau) and projects (such as the ALPHA Network and IeDEA Consortium) to ensure that latest methods and data are used in the preparation of the annual estimates. In the past year new methods and data have been introduced for pediatric estimates, incidence fitting, and ART mortality (described elsewhere in this supplement).

RESULTS

The 2016 version of Spectrum includes a number of other enhancements, including updated demographic data from the United Nations Population Division, program options for treatment (treat all), and programs to prevent mother-to-child transmission (option B+), improved methods to aggregate uncertainty to regional and global levels, several options for generating incidence trends, adjustments to the Estimations and Projections Package model to better incorporate aging effects, adjustments to account for the changing bias in prevalence from antenatal clinic surveillance, and an option to fit incidence among all adults 15+ in addition to 15-49.

CONCLUSION

The new methods and data implemented in the 2016 version of Spectrum allow national programs more flexibility in describing their programs and improve the estimates of key indicators and their uncertainty.

All-cause mortality in HIV-positive adults starting combination antiretroviral therapy: correcting for loss to follow-up

OBJECTIVE

To estimate mortality in HIV-positive patients starting combination antiretroviral therapy (ART) and to discuss different approaches to calculating correction factors to account for loss to follow-up.

METHODS

A total of 222 096 adult HIV-positive patients who started ART 2009-2014 in clinics participating in the International epidemiology Databases to Evaluate AIDS collaboration in 43 countries in sub-Saharan Africa, Asia Pacific, Latin America, and North America were included. To allow for underascertainment of deaths due to loss to follow-up, two correction factors (one for the period 0-6 months on ART and one for later periods) or 168 correction factors (combinations of two sexes, three time periods after ART initiation, four age groups, and seven CD4 groups) based on tracing patients lost in Kenya and data linkages in South Africa were applied. Corrected mortality rates were compared with a worst case scenario assuming all patients lost to follow-up had died.

RESULTS

Loss to follow-up differed between regions; rates were lowest in central Africa and highest in east Africa. Compared with using two correction factors (1.64 for the initial ART period and 2.19 for later), applying 168 correction factors (range 1.03-4.75) more often resulted in implausible mortality rates that exceeded the worst case scenario. Corrected mortality rates varied widely, ranging from 0.2 per 100 person-years to 54 per 100 person-years depending on region and covariates.

CONCLUSION

Implausible rates were less common with the simpler approach based on two correction factors. The corrected mortality rates will be useful to international agencies, national programmes, and modellers.

Improving estimates of children living with HIV from the Spectrum AIDS Impact Model

OBJECTIVE

Estimated numbers of children living with HIV determine programmatic and treatment needs. We explain the changes made to the UNAIDS estimates between 2015 and 2016, and describe the challenges around these estimates.

METHODS

Estimates of children newly infected, living with HIV, and dying of AIDS are developed by country teams using Spectrum software. Spectrum files are available for 160 countries, which represent 98% of the global population. In 2016, the methods were updated to reflect the latest evidence on mother-to-child HIV transmission and improved assumptions on the age children initiate antiretroviral therapy. We report updated results using the 2016 model and validate these estimates against mother-to-child transmission rates and HIV prevalence from population-based surveys for the survey year.

RESULTS

The revised 2016 model estimates 27% fewer children living with HIV in 2014 than the 2015 model, primarily due to changes in the probability of mother-to-child transmission among women with incident HIV during pregnancy. The revised estimates were consistent with population-based surveys of HIV transmission and HIV prevalence among children aged 5-9 years, but were lower than surveys among children aged 10-14 years.

CONCLUSIONS

The revised 2016 model is an improvement on previous models. Paediatric HIV models will continue to evolve as further improvements are made to the assumptions. Commodities forecasting and programme planning rely on these estimates, and increasing accuracy will be critical to enable effective scale-up and optimal use of resources. Efforts are needed to improve empirical measures of HIV prevalence, incidence, and mortality among children.

Improvements in Spectrum's fit to program data tool

OBJECTIVE

The Joint United Nations Program on HIV/AIDS-supported Spectrum software package (Glastonbury, Connecticut, USA) is used by most countries worldwide to monitor the HIV epidemic. In Spectrum, HIV incidence trends among adults (aged 15-49 years) are derived by either fitting to seroprevalence surveillance and survey data or generating curves consistent with program and vital registration data, such as historical trends in the number of newly diagnosed infections or people living with HIV and AIDS related deaths. This article describes development and application of the fit to program data (FPD) tool in Joint United Nations Program on HIV/AIDS' 2016 estimates round.

METHODS

In the FPD tool, HIV incidence trends are described as a simple or double logistic function. Function parameters are estimated from historical program data on newly reported HIV cases, people living with HIV or AIDS-related deaths. Inputs can be adjusted for proportions undiagnosed or misclassified deaths. Maximum likelihood estimation or minimum chi-squared distance methods are used to identify the best fitting curve. Asymptotic properties of the estimators from these fits are used to estimate uncertainty.

RESULTS

The FPD tool was used to fit incidence for 62 countries in 2016. Maximum likelihood and minimum chi-squared distance methods gave similar results. A double logistic curve adequately described observed trends in all but four countries where a simple logistic curve performed better.

CONCLUSION

Robust HIV-related program and vital registration data are routinely available in many middle-income and high-income countries, whereas HIV seroprevalence surveillance and survey data may be scarce. In these countries, the FPD tool offers a simpler, improved approach to estimating HIV incidence trends.

Age patterns and sex ratios of adult mortality in countries with high HIV prevalence

OBJECTIVE

To compare the 2016 United Nations Programme on HIV/AIDS (UNAIDS) modelled estimates of adult mortality in sub-Saharan Africa to empirical estimates.

DESIGN

Age-specific mortality rates were obtained from nationally representative sibling survival data, recent household deaths and vital registration, and directly compared with UNAIDS estimates. Orphanhood prevalence derived from UNAIDS mortality estimates was compared with survey and census reports on the survival of children's parents.

METHODS

Age-specific mortality rates for adults aged 15-59 years were calculated from Demographic and Health Surveys and deaths reported in censuses or vital registration, adjusted for underreporting, whenever possible. Proportions of orphans were extracted from censuses and surveys for children aged 5-9 years.

RESULTS

UNAIDS estimates were significantly higher than sibling mortality estimates, except among men in countries with very high HIV prevalence. There was a better agreement between rates based on household deaths or vital registration and model outputs. Sex ratios (M/F) of adult mortality were lower in UNAIDS estimates. The modelled orphan prevalence was significantly higher than in surveys and censuses, again with the exception of paternal orphans in countries with very high HIV prevalence. Ratios of paternal-to-maternal orphans were lower in the UNAIDS model than surveys and censuses. Among women, increases in mortality due to AIDS were more concentrated in the age range 25-50 years in model outputs, as compared with empirical estimates.

CONCLUSION

Discrepancies in levels, sex ratios and age patterns of adult mortality between empirical and UNAIDS estimates call for additional data quality assessments and improvements in estimation methods.

An epidemiological modelling study to estimate the composition of HIV-positive populations including migrants from endemic settings

OBJECTIVE

Migrants account for a significant number of people living with HIV in Europe, and it is important to fully consider this population in national estimates. Using a novel approach with the UK as an example, we present key public health measures of the HIV epidemic, taking into account both in-country infections and infections likely to have been acquired abroad.

DESIGN

Mathematical model calibrated to extensive data sources.

METHODS

An individual-based stochastic simulation model is used to calibrate to routinely collected surveillance data in the UK. Data on number of new HIV diagnoses, number of deaths, CD4 cell count at diagnosis, as well as time of arrival into the UK for migrants and the annual number of people receiving care were used.

RESULTS

An estimated 106 400 (90% plausibility range: 88 700-124 600) people were living with HIV in the UK in 2013. Twenty-three percent of these people, 24 600 (15 000-36 200) were estimated to be undiagnosed; this number has remained stable over the last decade. An estimated 32% of the total undiagnosed population had CD4 cell count less than 350 cells/μl in 2013. Twenty-five and 23% of black African men and women heterosexuals living with HIV were undiagnosed respectively.

CONCLUSION

We have shown a working example to characterize the HIV population in a European context which incorporates migrants from countries with generalized epidemics. Despite all aspects of HIV care being free and widely available to anyone in need in the UK, there is still a substantial number of people who are not yet diagnosed and thus not in care.

Surveillance and response for high-risk populations: what can malaria elimination programmes learn from the experience of HIV?

To eliminate malaria, malaria programmes need to develop new strategies for surveillance and response appropriate for the changing epidemiology that accompanies transmission decline, in which transmission is increasingly driven by population subgroups whose behaviours place them at increased exposure. Conventional tools of malaria surveillance and response are likely not sufficient in many elimination settings for accessing high-risk population subgroups, such as mobile and migrant populations (MMPs), given their greater likelihood of asymptomatic infections, illegal risk behaviours, limited access to public health facilities, and high mobility including extended periods travelling away from home. More adaptive, targeted strategies are needed to monitor transmission and intervention coverage effectively in these groups. Much can be learned from HIV programmes’ experience with “second generation surveillance”, including how to rapidly adapt surveillance and response strategies to changing transmission patterns, biological and behavioural surveys that utilize targeted sampling methods for specific behavioural subgroups, and methods for population size estimation. This paper reviews the strategies employed effectively for HIV programmes and offers considerations and recommendations for adapting them to the malaria elimination context.

Producing HIV estimates: from global advocacy to country planning and impact measurement

BACKGROUND

The development of global HIV estimates has been critical for understanding, advocating for and funding the HIV response. The process of generating HIV estimates has been cited as the gold standard for public health estimates.

OBJECTIVE

This paper provides important lessons from an international scientific collaboration and provides a useful model for those producing public health estimates in other fields.

DESIGN

Through the compilation and review of published journal articles, United Nations reports, other documents and personal experience we compiled historical information about the estimates and identified potential lessons for other public health estimation efforts.

RESULTS

Through the development of core partnerships with country teams, implementers, demographers, mathematicians, epidemiologists and international organizations, UNAIDS has led a process to develop the capacity of country teams to produce internationally comparable HIV estimates. The guidance provided by these experts has led to refinements in the estimated numbers of people living with HIV, new HIV infections and AIDS-related deaths over the past 20 years. A number of important updates to the methods since 1997 resulted in fluctuations in the estimated levels, trends and impact of HIV. The largest correction occurred between the 2005 and 2007 rounds with the additions of household survey data into the models. In 2001 the UNAIDS models at that time estimated there were 40 million people living with HIV. In 2016, improved models estimate there were 30 million (27.6-32.7 million) people living with HIV in 2001.

CONCLUSIONS

Country ownership of the estimation tools has allowed for additional uses of the results than had the results been produced by researchers or a team in Geneva. Guidance from a reference group and input from country teams have led to critical improvements in the models over time. Those changes have improved countries' and stakeholders' understanding of the HIV epidemic.

Undisclosed HIV infection and antiretroviral therapy use in the Kenya AIDS indicator survey 2012: relevance to national targets for HIV diagnosis and treatment

OBJECTIVES

This analysis assessed the impact of undisclosed HIV infection and antiretroviral therapy (ART) on national estimates of diagnosed HIV and ART coverage in Kenya.

METHODS

HIV-positive dried blood spot samples from Kenya's second AIDS Indicator Survey were tested for an antiretroviral biomarker by liquid chromatography-tandem mass spectrometry. Weighted estimates of diagnosed HIV and ART coverage based on self-report were compared with those corrected for undisclosed HIV infection and ART use based on antiretroviral test results. Multivariate analysis determined factors associated with undisclosed HIV infection and ART use among persons on ART.

RESULTS

The antiretroviral biomarker was detected in 42.5% [confidence interval (CI) 37.4-47.7] of HIV-infected persons. Antiretroviral drugs were present in 90.7% (CI 86.1-95.2) of HIV-infected persons reporting HIV-positive status and receiving ART, 66.7% (CI 59.9-73.4) reporting HIV-positive status irrespective of ART use, 21.0% (CI 13.4-28.6) reporting HIV-negative status, and 19.3% (CI 9.0-29.5) reporting no previous HIV test. After correcting for undisclosed HIV infection and ART use, diagnosed HIV increased from 46.9 to 57.2% and ART coverage increased from 31.8 to 42.8%. Undisclosed HIV infection while on ART was associated with being aged 25-39 years and not visiting a health provider in the past year, while younger age and higher wealth were associated with undisclosed ART use.

CONCLUSION

Substantial levels of undisclosed HIV infection and ART use among persons on ART were observed, resulting in diagnosed HIV underestimated by approximately 112000 persons and ART coverage by approximately 131000 persons. Supplementing self-reported ART status with objective measures of ART use in national population-based serosurveys can improve monitoring of HIV diagnosis and treatment targets in countries.

Modeling Impact and Cost-Effectiveness of Increased Efforts to Attract Voluntary Medical Male Circumcision Clients Ages 20-29 in Zimbabwe

Background

Zimbabwe aims to increase circumcision coverage to 80% among 13- to 29-year-olds. However, implementation data suggest that high coverage among men ages 20 and older may not be achievable without efforts specifically targeted to these men, incurring additional costs per circumcision. Scale-up scenarios were created based on trends in implementation data in Zimbabwe, and the cost-effectiveness of increasing efforts to recruit clients ages 20–29 was examined.

Methods

Zimbabwe voluntary medical male circumcision (VMMC) program data were used to project trends in male circumcision coverage by age into the future. The projection informed a base scenario in which, by 2018, the country achieves 80% circumcision coverage among males ages 10–19 and lower levels of coverage among men above age 20. The Zimbabwe DMPPT 2.0 model was used to project costs and impacts, assuming a US$109 VMMC unit cost in the base scenario and a 3% discount rate. Two other scenarios assumed that the program could increase coverage among clients ages 20–29 with a corresponding increase in unit cost for these age groups.

Results

When circumcision coverage among men ages 20–29 is increased compared with a base scenario reflecting current implementation trends, fewer VMMCs are required to avert one infection. If more than 50% additional effort (reflected as multiplying the unit cost by >1.5) is required to double the increase in coverage among this age group compared with the base scenario, the cost per HIV infection averted is higher than in the base scenario.

Conclusions

Although increased investment in recruiting VMMC clients ages 20–29 may lead to greater overall impact if recruitment efforts are successful, it may also lead to lower cost-effectiveness, depending on the cost of increasing recruitment. Programs should measure the relationship between increased effort and increased ability to attract this age group.

Impact and Cost of Scaling Up Voluntary Medical Male Circumcision for HIV Prevention in the Context of the New 90-90-90 HIV Treatment Targets

Background

The report of the Joint United Nations Programme on HIV/AIDS (UNAIDS) for World AIDS Day 2014 highlighted a Fast-Track Strategy that sets ambitious treatment and prevention targets to reduce global HIV incidence to manageable levels by 2020 and end the AIDS epidemic by 2030. The 90-90-90 treatment targets for 2020 call for 90% of people living with HIV to know their HIV status, 90% of people who know their status to receive treatment, and 90% of people on HIV treatment to be virally suppressed. This paper examines how scale-up of voluntary medical male circumcision (VMMC) services in four priority countries in sub-Saharan Africa could contribute to ending the AIDS epidemic by 2030 in the context of concerted efforts to close the treatment gap, and what the impact of VMMC scale-up would be if the 90-90-90 treatment targets were not completely met.

Methods

Using the Goals module of the Spectrum suite of models, this analysis modified ART (antiretroviral treatment) scale-up coverage from base scenarios to reflect the 90-90-90 treatment targets in four countries (Lesotho, Malawi, South Africa, and Uganda). In addition, a second scenario was created to reflect viral suppression levels of 75% instead of 90%, and a third scenario was created in which the 90-90-90 treatment targets are reached in women, with men reaching more moderate coverage levels. Regarding male circumcision (MC) coverage, the analysis examined both a scenario in which VMMCs were assumed to stop after 2015, and one in which MC coverage was scaled up to 90% by 2020 and maintained at 90% thereafter.

Results

Across all four countries, scaling up VMMC is projected to provide further HIV incidence reductions in addition to those achieved by reaching the 90-90-90 treatment targets. If viral suppression levels only reach 75%, scaling up VMMC leads to HIV incidence reduction to nearly the same levels as those achieved with 90-90-90 without VMMC scale-up. If only women reach the 90-90-90 targets, scaling up VMMC brings HIV incidence down to near the levels projected with 90-90-90 without VMMC scale-up. Regarding cost, scaling up VMMC increases the annual costs during the scale-up phase, but leads to lower annual costs after the MC coverage target is achieved.

Conclusions

The scenarios modeled in this paper show that the highly durable and effective male circumcision intervention increases epidemic impact levels over those of treatment-only strategies, including the case if universal levels of viral suppression in men and women are not achieved by 2020. In the context of 90-90-90, prioritizing continued successful scale-up of VMMC increases the possibility that future generations will be free not only of AIDS but also of HIV.

Estimates of global, regional, and national incidence, prevalence, and mortality of HIV, 1980-2015: the Global Burden of Disease Study 2015

BACKGROUND

Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation. In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015.

METHODS

For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification.

FINDINGS

Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95% uncertainty interval [UI] 3·1-3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5-2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6-40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7-1·9 million) in 2005, to 1·2 million deaths (1·1-1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections.

INTERPRETATION

Scale-up of ART and prevention of mother-to-child transmission has been one of the great successes of global health in the past two decades. However, in the past decade, progress in reducing new infections has been slow, development assistance for health devoted to HIV has stagnated, and resources for health in low-income countries have grown slowly. Achievement of the new ambitious goals for HIV enshrined in Sustainable Development Goal 3 and the 90-90-90 UNAIDS targets will be challenging, and will need continued efforts from governments and international agencies in the next 15 years to end AIDS by 2030.

FUNDING

Bill & Melinda Gates Foundation, and National Institute of Mental Health and National Institute on Aging, National Institutes of Health.

Assessing Progress, Impact, and Next Steps in Rolling Out Voluntary Medical Male Circumcision for HIV Prevention in 14 Priority Countries in Eastern and Southern Africa through 2014

Background

In 2007, the World Health Organization and the Joint United Nations Programme on HIV/AIDS (UNAIDS) identified 14 priority countries across eastern and southern Africa for scaling up voluntary medical male circumcision (VMMC) services. Several years into this effort, we reflect on progress.

Methods

Using the Decision Makers’ Program Planning Tool (DMPPT) 2.1, we assessed age-specific impact, cost-effectiveness, and coverage attributable to circumcisions performed through 2014. We also compared impact of actual progress to that of achieving 80% coverage among men ages 15–49 in 12 VMMC priority countries and Nyanza Province, Kenya. We populated the models with age-disaggregated VMMC service statistics and with population, mortality, and HIV incidence and prevalence projections exported from country-specific Spectrum/Goals files. We assumed each country achieved UNAIDS’ 90-90-90 treatment targets.

Results

More than 9 million VMMCs were conducted through 2014: 43% of the estimated 20.9 million VMMCs required to reach 80% coverage by the end of 2015. The model assumed each country reaches the UNAIDS targets, and projected that VMMCs conducted through 2014 will avert 240,000 infections by the end of 2025, compared to 1.1 million if each country had reached 80% coverage by the end of 2015. The median estimated cost per HIV infection averted was $4,400. Nyanza Province in Kenya, the 11 priority regions in Tanzania, and Uganda have reached or are approaching MC coverage targets among males ages 15–24, while coverage in other age groups is lower. Across all countries modeled, more than half of the projected HIV infections averted were attributable to circumcising 10- to 19-year-olds.

Conclusions

The priority countries have made considerable progress in VMMC scale-up, and VMMC remains a cost-effective strategy for epidemic impact, even assuming near-universal HIV diagnosis, treatment coverage, and viral suppression. Examining circumcision coverage by five-year age groups will inform countries’ decisions about next steps.

Voluntary Medical Male Circumcision for HIV Prevention in Malawi: Modeling the Impact and Cost of Focusing the Program by Client Age and Geography

Background

In 2007, the World Health Organization (WHO) recommended scaling up voluntary medical male circumcision (VMMC) in priority countries with high HIV prevalence and low male circumcision (MC) prevalence. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), an estimated 5.8 million males had undergone VMMC by the end of 2013. Implementation experience has raised questions about the need to refocus VMMC programs on specific subpopulations for the greatest epidemiological impact and programmatic effectiveness. As Malawi prepared its national operational plan for VMMC, it sought to examine the impacts of focusing on specific subpopulations by age and region.

Methods

We used the Decision Makers’ Program Planning Toolkit, Version 2.0, to study the impact of scaling up VMMC to different target populations of Malawi. National MC prevalence by age group from the 2010 Demographic and Health Survey was scaled according to the MC prevalence for each district and then halved, to adjust for over-reporting of circumcision. In-country stakeholders advised a VMMC unit cost of $100, based on implementation experience. We derived a cost of $451 per patient-year for antiretroviral therapy from costs collected as part of a strategic planning exercise previously conducted in- country by UNAIDS.

Results

Over a fifteen-year period, circumcising males ages 10–29 would avert 75% of HIV infections, and circumcising males ages 10–34 would avert 88% of infections, compared to the current strategy of circumcising males ages 15–49. The Ministry of Health’s South West and South East health zones had the lowest cost per HIV infection averted. Moreover, VMMC met WHO’s definition of cost-effectiveness (that is, the cost per disability-adjusted life-year [DALY] saved was less than three times the per capita gross domestic product) in all health zones except Central East. Comparing urban versus rural areas in the country, we found that circumcising men in urban areas would be both cost-effective and cost-saving, with a VMMC cost per DALY saved of $120 USD and with 15 years of VMMC implementation resulting in lifetime HIV treatment costs savings of $331 million USD.

Conclusions

Based on the age analyses and programmatic experience, Malawi’s VMMC operational plan focuses on males ages 10–34 in all districts in the South East and South West zones, as well as Lilongwe (an urban district in the Central zone). This plan covers 14 of the 28 districts in the country.

The Economic and Epidemiological Impact of Focusing Voluntary Medical Male Circumcision for HIV Prevention on Specific Age Groups and Regions in Tanzania

Background

Since its launch in 2010, the Tanzania National Voluntary Medical Male Circumcision (VMMC) Program has focused efforts on males ages 10–34 in 11 priority regions. Implementers have noted that over 70% of VMMC clients are between the ages of 10 and 19, raising questions about whether additional efforts would be required to recruit men age 20 and above. This analysis uses mathematical modeling to examine the economic and epidemiological consequences of scaling up VMMC among specific age groups and priority regions in Tanzania.

Methods and Findings

Analyses were conducted using the Decision Makers’ Program Planning Tool Version 2.0 (DMPPT 2.0), a compartmental model implemented in Microsoft Excel 2010. The model was populated with population, mortality, and HIV incidence and prevalence projections from external sources, including outputs from Spectrum/AIDS Impact Module (AIM). A separate DMPPT 2.0 model was created for each of the 11 priority regions. Tanzania can achieve the most immediate impact on HIV incidence by circumcising males ages 20–34. This strategy would also require the fewest VMMCs for each HIV infection averted. Circumcising men ages 10–24 will have the greatest impact on HIV incidence over a 15-year period. The most cost-effective approach (lowest cost per HIV infection averted) targets men ages 15–34. The model shows the VMMC program is cost saving in all 11 priority regions. VMMC program cost-effectiveness varies across regions due to differences in projected HIV incidence, with the most cost-effective programs in Njombe and Iringa.

Conclusions

The DMPPT 2.0 results reinforce Tanzania’s current VMMC strategy, providing newfound confidence in investing in circumcising adolescents. Tanzanian policy makers and program implementers will continue to focus scale-up of VMMC on men ages 10–34 years, seeking to maximize program impact and cost-effectiveness while acknowledging trends in demand among the younger and older age groups.