Estimation And Projection Package Research Articles

Subnational mapping of HIV incidence and mortality among individuals aged 15–49 years in sub-Saharan Africa, 2000–18: a modelling study

SummaryBackgroundHigh-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa.MethodsIn this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15–49 years. We used a model-based geostatistical framework to estimate HIV prevalence at the second administrative level in 44 countries in sub-Saharan Africa for 2000–18 and sought data on the number of individuals on antiretroviral therapy (ART) by second-level administrative unit. We then modified the Estimation and Projection Package (EPP) to use these HIV prevalence and treatment estimates to estimate HIV incidence and mortality by second-level administrative unit.FindingsThe estimates suggest substantial variation in HIV incidence and mortality rates both between and within countries in sub-Saharan Africa, with 15 countries having a ten-times or greater difference in estimated HIV incidence between the second-level administrative units with the lowest and highest estimated incidence levels. Across all 44 countries in 2018, HIV incidence ranged from 2·8 (95% uncertainty interval 2·1–3·8) in Mauritania to 1585·9 (1369·4–1824·8) cases per 100 000 people in Lesotho and HIV mortality ranged from 0·8 (0·7–0·9) in Mauritania to 676·5 (513·6–888·0) deaths per 100 000 people in Lesotho. Variation in both incidence and mortality was substantially greater at the subnational level than at the national level and the highest estimated rates were accordingly higher. Among second-level administrative units, Guijá District, Gaza Province, Mozambique, had the highest estimated HIV incidence (4661·7 [2544·8–8120·3]) cases per 100 000 people in 2018 and Inhassunge District, Zambezia Province, Mozambique, had the highest estimated HIV mortality rate (1163·0 [679·0–1866·8]) deaths per 100 000 people. Further, the rate of reduction in HIV incidence and mortality from 2000 to 2018, as well as the ratio of new infections to the number of people living with HIV was highly variable. Although most second-level administrative units had declines in the number of new cases (3316 [81·1%] of 4087 units) and number of deaths (3325 [81·4%]), nearly all appeared well short of the targeted 75% reduction in new cases and deaths between 2010 and 2020.InterpretationOur estimates suggest that most second-level administrative units in sub-Saharan Africa are falling short of the targeted 75% reduction in new cases and deaths by 2020, which is further compounded by substantial within-country variability. These estimates will help decision makers and programme implementers expand access to ART and better target health resources to higher burden subnational areas.FundingBill & Melinda Gates Foundation.

Heterogeneity in geographical trends of HIV epidemics among key populations in Pakistan: a mathematical modeling study of survey data.

BackgroundAssessing patterns and trends in new infections is key to better understanding of HIV epidemics, and is best done through monitoring changes in incidence over time. In this study, we examined disparities in geographical trends of HIV epidemics among people who inject drugs (PWIDs), female sex workers (FSWs) and hijra/transgender/male sex workers (H/MSWs), in Pakistan.MethodsThe UNAIDS Estimation and Projection Package (EPP) mathematical model was used to explore geographical trends in HIV epidemics. Four rounds of mapping and surveillance data collected among key populations (KPs) across 20 cities in Pakistan between 2005-2011 was used for modeling. Empirical estimates of HIV prevalence of each KP in each city were used to fit the model to estimate prevalence and incidence over time.ResultsHIV incidence among PWIDs in Pakistan reached its peak in 2011, estimated at 45.3 per 1000 person-years. Incidence was projected to continue to rise from 18.9 in 2015 to 24.3 in 2020 among H/MSWs and from 3.2 in 2015 to 6.3 in 2020 among FSWs. The number of people living with HIV in Pakistan was estimated to steadily increase through at least 2020. HIV incidence peak among PWIDs ranged from 16.2 in 1997 in Quetta to 71.0 in 2010 in Faisalabad (per 1000 person-years). Incidence among H/MSWs may continue to rise through 2020 in all the cities, except in Larkana where it peaked in the early 2000s. In 2015, model estimated incidence among FSWs was 8.1 in Karachi, 6.6 in Larkana, 2.0 in Sukkur and 1.2 in Lahore (per 1000 person-years).ConclusionsThere exists significant geographical heterogeneity in patterns and trends of HIV sub-epidemics in Pakistan. Focused interventions and service delivery approaches, different by KP and city, are recommended.

Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

Fitting HIV Prevalence 1981 Onwards for Three Indian States Using the Goals Model and the Estimation and Projection Package.

Models are designed to provide evidence for strategic program planning by examining the impact of different interventions on projected HIV incidence. We employed the Goals Model to fit the HIV epidemic curves in Andhra Pradesh, Maharashtra and Tamil Nadu states of India where HIV epidemic is considered to have matured and in a declining phase. Input data in the Goals Model consisted of demographic, epidemiological, transmission-related and risk group wise behavioral parameters. The HIV prevalence curves generated in the Goals Model for each risk group in the three states were compared with the epidemic curves generated by the Estimation and Projection Package (EPP) that the national program is routinely using. In all the three states, the HIV prevalence trends for high-risk populations simulated by the Goals Model matched well with those derived using state-level HIV surveillance data in the EPP. However, trends for the low- and medium-risk populations differed between the two models. This highlights the need to generate more representative and robust data in these sub-populations and consider some structural changes in the modeling equation and parameters in the Goals Model to effectively use it to assess the impact of future strategies of HIV control in various sub-populations in India at the sub-national level.

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

SummaryBackgroundTimely 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.MethodsFor 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.FindingsGlobal 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.InterpretationScale-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.FundingBill & Melinda Gates Foundation, and National Institute of Mental Health and National Institute on Aging, National Institutes of Health.

The missed HIV-positive children of Ethiopia.

ObjectiveAs elsewhere, due to scarcity of data and limited awareness of HIV infection, especially in older children, the HIV epidemic among Ethiopian children appears neglected in national programs (children ART coverage is of only 12% in 2013). This paper estimates the country burden of HIV in older children and investigates the prevalence of HIV in orphans and vulnerable children (OVC) households.Design/MethodsWe analyzed national HIV data for Ethiopia, using Spectrum/ Estimation and Projection Package (EPP) and primary data on children living in households with at least one HIV-positive adult in the Amhara and Tigrai regions. Descriptive analysis of the age and sex distribution of HIV-positive OVC in Ethiopia was performed.ResultsOur Spectrum/EPP analysis estimated the population of HIV-positive children under 15 years old to be 160,000 in 2013. The majority of children (81•6%) were aged five to 14 years. The estimated number of orphans due to AIDS was 800,000. The empirical data from almost 10,000 OVC under 18 years showed 11•9% were HIV-positive, the majority of whom were between five and 10 years old with no significant difference between males and females.ConclusionsThere is a large population of children living with HIV in Ethiopia, the magnitude of which not previously recognized. The majority were vertically infected and never identified nor linked into treatment. OVC represent a reachable group which could account for a substantial proportion of the HIV infected older children. We recommend that HIV programs urgently synergize with social protection sectors and address these children with HIV testing and related services.

Incorporating incidence information within the UNAIDS Estimation and Projection Package framework: a study based on simulated incidence assay data.

Objectives:The objective of this study is to extend the UNAIDS incidence estimation model, the UNAIDS Estimation and Projection Package (EPP), so that it can incorporate data from incidence assays.Methods:We propose combining the likelihood of the incidence assay data with the likelihood of other data, in a manner that is consistent with the biomarker-based incidence estimator using incidence assay data. Two calibrating parameters specify the performance of the incidence assays: the false recent rate and the mean duration of recent infection. We then use synthetic data, based on prevalence data obtained from antenatal clinic surveillances, and in some cases household surveys, from 24 countries, to examine the impact of including incidence assay data, under circumstances wherein the incidence assay data imply the same or a different incidence rate as that inferred from the prevalence data alone, and wherein incorrect calibrating parameters for the incidence assay data are used.Results:Using incidence assay data, in addition to prevalence data, can improve estimate by narrowing uncertainty intervals in derived HIV incidence estimates, and by providing information on levels or trends in incidence that were not apparent in the prevalence data alone. However, the effect is relatively modest if the sample size of the incidence assay survey is small and results can be biased if the calibrating parameters for the incidence assay data are not known accurately.Conclusion:Incorporating information from incidence assays in the manner proposed has the potential to improve estimates. Further work will examine in more detail the circumstances under which the contribution of incidence assay data would be most valuable.

Updates to the Spectrum/Estimation and Projection Package (EPP) model to estimate HIV trends for adults and children

BackgroundThe Spectrum and Estimation and Projection Package (EPP) programs are used to estimate key HIV indicators based on HIV surveillance and surveys, programme statistics and epidemic patterns. These indicators include...

Spline-based modelling of trends in the force of HIV infection, with application to the UNAIDS Estimation and Projection Package

ObjectiveWe previously developed a flexible specification of the UNAIDS Estimation and Projection Package (EPP) that relied on splines to generate time-varying values for the force of infection parameter. Here, we...

Modelling national HIV/AIDS epidemics: revised approach in the UNAIDS Estimation and Projection Package 2011

ObjectiveUnited Nations Programme on HIV/AIDS reports regularly on estimated levels and trends in HIV/AIDS epidemics, which are evaluated using an epidemiological model within the Estimation and Projection Package (EPP). The relatively simple four-parameter model of HIV incidence used in EPP through the previous round of estimates has encountered challenges when attempting to fit certain data series on prevalence over time, particularly in settings with long running epidemics where prevalence has increased recently. To address this, the most recent version of the modelling package (EPP 2011) includes a more flexible epidemiological model that allows HIV infection risk to vary over time. This paper describes the technical details of this flexible approach to modelling HIV transmission dynamics within EPP 2011.MethodologyFor the flexible modelling approach, the force of infection parameter, r, is allowed to vary over time through a random walk formulation, and an informative prior distribution is used to improve short-term projections beyond the last year of data. Model parameters are estimated using a Bayesian estimation approach in which models are fit to HIV seroprevalence data from surveillance sites.ResultsThis flexible model can yield better estimates of HIV prevalence over time in situations where the classic EPP model has difficulties, such as in Uganda, where prevalence is no longer falling. Based on formal out-of-sample projection tests, the flexible modelling approach also improves predictions and CIs for extrapolations beyond the last observed data point.ConclusionsWe recommend use of a flexible modelling approach where data are sufficient (eg, where at least 5 years of observations are available), and particularly where an epidemic is beyond its peak.

Application of Estimation and Projection Package and Spectrum to the Context of Australia’s HIV Epidemic

Objectives: Understanding and monitoring the HIV epidemic is essential for developing and evaluating public health responses. The Joint United Nations Programme on AIDS (UNAIDS) Estimation and Projection Package (EPP) and Spectrum have become a standard tool to interpret HIV surveillance systems in many settings, particularly in low- and middle-income countries where surveillance data is often based on serial cross-sectional prevalence studies and not on notifications. EPP has not previously been used to evaluate the HIV epidemic in Australia. We derived best HIV estimates using EPP and assumptions that reflect the current understanding of HIV epidemiology in Australia and compared derived estimates with independent estimates and estimates from mathematical models using backprojections method. Methods: The epidemic curves for different population groups (i.e., men who have sex with men, injecting drug users, and low-risk population) generated by EPP were combined with antiretroviral therapy (ART) data into a demographic projection model, Spectrum to determine the consequences of the HIV epidemic in Australia. Results: The overall pattern of the HIV epidemic was consistent with both independent estimates and backprojection modelling estimates. However, the number of HIV-infected females, AIDS-related deaths, and the number in need of ART estimated by EPP were approximately 3.7 times, 20 times, and 6.3 times, respectively higher than independent estimates based on our current surveillance system. EPP estimates of new HIV infections were, however, half the number of independent and back-projection estimates. Conclusions: These findings suggest that customized tools that are tailored to the unique epidemiology and surveillance mechanisms in each setting are required to enable effective programmatic response and policy.

Estimation and Projection of the HIV Epidemic Trend among the Migrant Population in China

Objective The migrant population is a vulnerable group for HIV infection in China. Understanding potential epidemic trends among migrants is critical for developing HIV preventative measures in this population. Methods The Estimation and Projection Package (EPP) model was used to process prefecture and county-level surveillance data to generate HIV prevalence and epidemic trends for migrant populations in China. Results The prevalence of HIV among migrants in 2009 was estimated at 0.075% (95% CI: 0.042%, 0.108%) in China. The HIV epidemic among migrants is likely to increase over the next 5 years, with the prevalence expected to reach 0.110% (95% CI: 0.070%, 0.150%) by 2015. Conclusion Although the 2009 estimates for the HIV/AIDS epidemic in China indicate a slower rate of increase compared with the national HIV/AIDS epidemic, it is estimated to persistently increase among migrants over the next 5 years. Migrants will have a strong impact on the overall future of the HIV epidemic trend in China and evidence-based prevention and monitoring efforts should be expanded for this vulnerable population.

National estimate of HIV prevalence in the Netherlands: comparison and applicability of different estimation tools

to determine limitations and strengths of three methodologies developed to estimate HIV prevalence and the number of people living with HIV/AIDS (PLWHA). the UNAIDS/WHO Workbook method; the Multiparameter Evidence Synthesis (MPES) adopted by the Health Protection Agency; and the UNAIDS/WHO Estimation and Projection Package (EPP) and Spectrum method were used and their applicability and feasibility were assessed. All methods estimate the number infected in mutually exclusive risk groups among 15-70-year-olds. using data from the Netherlands, the Workbook method estimated 23 969 PLWHA as of January 2008. MPES estimated 21 444 PLWHA, with a 95% credible interval (CrI) of 17 204-28 694. Adult HIV prevalence was estimated at 0.2% (95% CrI 0.15-0.24%) and 40% (95% CrI 25-55%) were undiagnosed. Spectrum applied gender-specific mortality, resulting in a projected estimate of 19 115 PLWHA. although outcomes differed between the methods, they broadly concurred. An advantage of MPES is that the proportion diagnosed can be estimated by risk group, which is important for policy guidance. However, before MPES can be used on a larger scale, it should be made more easily applicable. If the aim is not only to obtain annual estimates, but also short-term projections, then EPP and Spectrum are more suitable. Research into developing and refining analytical tools, which make use of all available information, is recommended, especially HIV diagnosed cases, as this information is becoming routinely collected in most countries with concentrated HIV epidemics.

Using Estimation and Projection Package and Spectrum for Jamaica's national HIV estimates and targets

BackgroundAdequate coverage of target populations ensures that desired outcomes, such as increased survival of people living with HIV, are achieved. However, estimates of coverage and impact of HIV programmes using...

A stochastic infection rate model for estimating and projecting national HIV prevalence rates

BackgroundEvery 2 years, the Joint United Nations Programme on HIV/AIDS (UNAIDS) produces probabilistic estimates and projections of HIV prevalence rates for countries with generalised HIV/AIDS epidemics. To do this they...

The 2009 HIV and AIDS estimates and projections: methods, tools and analyses

Since 2004 we have provided detailed descriptions of the tools and assumptions used in generating HIV and AIDS estimates, as well as the data and analyses underpinning them.1–3 The UNAIDS...

Flexible epidemiological model for estimates and short-term projections in generalised HIV/AIDS epidemics

ObjectiveUNAIDS and country analysts use a simple infectious disease model, embedded in the Estimation and Projection Package (EPP), to generate annual updates on the global HIV/AIDS epidemic. Our objective was...

Estimation and prediction of the epidemic situation of acquired immunodeficiency syndrome in Jiangsu province

The aim of this study was to estimate and predict the AIDS epidemic situation in Jiangsu province by using a software named Estimation and Projection Package (EPP) and then to provide accurate information for making control plans and conducting interventions. Date were obtained from the comprehensively monitored sentinels of AIDS and venereal diseases (Data were from 28 national monitored stations and 52 provincial stations. From 2003 to 2009, a total of 10 730 000 people had been monitored) as well as project survey and laboratory tests. EPP epidemic model was employed to analyze the prevalence and to predict future epidemic situations. A total of 830 000 and 1 020 000 people were monitored in 2003 and 2004 respectively, and 8 880 000 more people were monitored in the following 5 years. By the end of 2009, a total of 4103 HIV infection cases had been reported, among which 918 people were diagnosed with AIDS and 432 died. Since 2003, the cases infected through IDU had decreased from 66.84% (262/392) to 16.40% (142/868). However, the cases infected through sex contact had increased from 21.68% (85/392) to 77.40% (672/868). Among these cases, homosexual transmission and heterosexual transmission accounted for 39.10% (339/868) and 38.30% (333/868) respectively. It was estimated that there would be 14 290 HIV/AIDS cases in 2011 which is 18.10% (2191/12 099) higher than that in 2009. The estimated HIV infection rate would be 0.02%. EPP prediction showed the AIDS epidemic situation in Jiangsu province had an ascendant trend and the AIDS epidemic situation had demonstrated rapid growth. Therefore, it is necessary to take effective preventive measures to control the spread of AIDS.

Modelling HIV epidemics in the antiretroviral era: the UNAIDS Estimation and Projection package 2009

ObjectiveThe UNAIDS Estimation and Projection Package (EPP) is a tool for country-level estimation and short-term projection of HIV/AIDS epidemics based on fitting observed HIV surveillance data on prevalence. This paper...

The implementation of EPP software using HIV prevalence data from studies conducted in Greece

Background In Greece, HIV/AIDS surveillance is based mainly on the case reporting system, which, however, is affected by patterns of testing and reporting. Specific information on the prevalence and incidence of HIV disease is required for an effective and well-planned response to the epidemic. The Estimation and Projection Package (EPP) is a software developed by UNAIDS and partners, which assists countries to map their HIV epidemic on the basis of available HIV prevalence data. The aims of the present study include: i) the systematic review of Greek and international literature in order to retrieve relevant HIV prevalence studies carried out in Greece, and ii) the use of the extracted prevalence estimates in EPP to produce the Greek epidemic curve.