An estimated 4.9 million adults received antiretroviral therapy (ART) in low and middle income countries in 2009. A further estimated 700 000 adults received ART in high-income countries. The impact ...of providing ART is not often quantifiable due to limited monitoring systems. One measure, life-years gained, provides a standardised measure that shows the survival impact of ART on the population while controlling for variations in underlying survival. Measuring life-years gained allows a comparison of the impact of ART between regions.
Using the Spectrum computer package, two different scenarios were created for 151 countries. One scenario describes the results of providing adults with ART as reported by countries between 1995 and 2009, the second scenario describes a situation in which no ART was provided to adults living with HIV between 1995 and 2009. The difference in the number of life-years accrued among adults in the two scenarios is compared and summarised by geographical region.
An estimated 14.4 million life-years have been gained among adults globally between 1995 and 2009 as a result of ART. 54 % of these years were gained in western Europe and North America, where ART has been available for over 10 years. In recent years the growth in life-years has occurred more rapidly in sub-Saharan Africa and Asia.
The substantial impact of ART described here provides evidence to argue for continued support of sustainable ART programmes in low and middle-income countries. Strengthening ART monitoring systems and mortality surveillance in low and middle-income countries will make this evidence more accessible to programme managers.
Countries measure trends in HIV incidence to assess the impact of HIV prevention and treatment programmes. Most countries have approximated trends in HIV incidence through modelled estimates or ...through trends in HIV prevalence among young people (aged 15-24 years) assuming they have recently become sexually active and have thus only been recently exposed to HIV.
Trends in HIV incidence are described and results are compared using three proxy measures of incidence: HIV prevalence among young women attending antenatal clinics (ANCs) in 22 countries; HIV prevalence among young male and female nationally representative household survey respondents in 14 countries; and modelled estimates of adult (ages 15-49 years) HIV incidence in 26 countries. The significance of changes in prevalence among ANC attendees and young survey respondents is tested.
Among 26 countries, 25 had evidence of some decline in HIV incidence and 15 showed statistically significant declines in either ANC data or survey data. Only in Mozambique did the direction of the trend in young ANC attendees differ from modelled adult incidence, and in Mali and Zambia trends among young men differed from trends in adult incidence. The magnitude of change differed by method.
Trends in HIV prevalence among young people show encouraging declines. Changes in fertility patterns, HIV-infected children surviving to adulthood, and participation bias could affect future proxy measures of incidence trends.
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.
Introduction
Findings from biomedical, behavioural and implementation studies provide a rich foundation to guide programmatic efforts for the prevention of mother‐to‐child HIV transmission (PMTCT).
...Methods
We summarized the current evidence base to support policy makers, programme managers, funding agencies and other stakeholders in designing and optimizing PMTCT programmes. We searched the scientific literature for PMTCT interventions in the era of universal antiretroviral therapy for pregnant and breastfeeding women (i.e. 2013 onward). Where evidence was sparse, relevant studies from the general HIV treatment literature or from prior eras of PMTCT programme implementation were also considered. Studies were organized into six categories: HIV prevention services for women, timely access to HIV testing, timely access to ART, programme retention and adherence support, timely engagement in antenatal care and services for infants at highest risk of HIV acquisition. These were mapped to specific missed opportunities identified by the UNAIDS Spectrum model and embedded in UNICEF operational guidance to optimize PMTCT services.
Results and discussion
From May to November 2019, we identified numerous promising, evidence‐based strategies that, properly tailored and adopted, could contribute to population reductions in vertical HIV transmission. These spanned the HIV and maternal and child health literature, emphasizing the importance of continued alignment and integration of services. We observed overlap between several intervention domains, suggesting potential for synergies and increased downstream impact. Common themes included integration of facility‐based healthcare; decentralization of health services from facilities to communities; and engagement of partners, peers and lay workers for social support. Approaches to ensure early HIV diagnosis and treatment prior to pregnancy would strengthen care across the maternal lifespan and should be promoted in the context of PMTCT.
Conclusions
A wide range of effective strategies exist to improve PMTCT access, uptake and retention. Programmes should carefully consider, prioritize and plan those that are most appropriate for the local setting and best address existing gaps in PMTCT health services.
In 2020, there were an estimated 1·7 million children younger than 15 years living with HIV worldwide, but there are few data on the proportion of children living with HIV who are undiagnosed. We ...aimed to estimate the prevalence of undiagnosed HIV among children living with HIV in Eswatini, Lesotho, Malawi, Namibia, Tanzania, Zambia, and Zimbabwe.
We conducted an analysis of data from the cross-sectional Population-based HIV Impact Assessment (PHIA) surveys from 2015 to 2017. PHIAs are nationally representative surveys measuring HIV outcomes. HIV rapid test data (with PCR confirmatory testing for children aged <18 months) were used to measure HIV prevalence among children in each country (Eswatini, Lesotho, Malawi, Namibia, Tanzania, Zambia, and Zimbabwe). Mothers or guardians reported previous HIV testing of children and previous results. Detection of antiretroviral medications was done using dried blood spots. Children who tested positive in the PHIA with previous negative or unknown HIV test results and without detectable antiretroviral medication blood concentrations were considered previously undiagnosed; all other children who tested positive were considered previously diagnosed. Survey weights with jackknife variance were used to generate national estimates of HIV prevalence and undiagnosed HIV in children aged 1-14 years. We also report the prevalence (weighted proportions) of antiretroviral therapy coverage and viral load suppression (<400 copies per mL).
Between 2015 and 2017, 42 248 children aged 1-14 years were included in the surveys, of whom 594 were living with HIV. Across the seven countries, the estimated weighted HIV prevalence was 0·9% (probability band 0·7-1·1) and we estimated that there were 425 000 (probability band 365 000-485 000) children living with HIV. Among all children living with HIV, 61·0% (n=259 000 probability band 216 000-303 000) were previously diagnosed and 39·0% (n=166 000 128 000-204 000) had not been previously diagnosed with HIV. Among previously diagnosed children living with HIV, 88·4% had detectable antiretroviral medication blood concentrations and 48·3% had viral load suppression. Among all children living with HIV (regardless of previous diagnosis status), 54·7% had detectable antiretroviral medication blood concentrations and 32·6% had viral load suppression.
Our findings show the uneven coverage of paediatric HIV testing across these seven countries and underscore the urgent need to address gaps in diagnosis and treatment for all children living with HIV.
None.
In 2015, WHO and UNAIDS released new guidance recommending that countries transition from conducting antenatal clinic (ANC) unlinked anonymous testing (ANC-UAT) for tracking HIV prevalence trends ...among pregnant women to using ANC routine testing (ANC-RT) data, which are more consistent and economic to collect. This transition could pose challenges for distinguishing whether changes in observed prevalence are due to a change in underlying population prevalence or due to a change in the testing approach. We compared the HIV prevalence measured from ANC-UAT and ANC-RT in 15 countries that had both data sources in overlapping years. We used linear mixed-effects model (LMM) to estimate the RT-to-UAT calibration parameter as well as other unobserved quantities. We summarized the results at different levels of aggregation (e.g., country, urban, rural, and province). Based on our analysis, the HIV prevalence measured by ANC-UAT and ANC-RT data are consistent in most countries. Therefore, if large discrepancy is observed between ANC-UAT and ANC-RT at the same location, we recommend that people should be cautious and investigate the reason. For countries that lack information to estimate the calibration parameter, we propose an informative prior distribution of mean 0 and standard deviation 0.2 for the RT-to-UAT calibration parameter.
The Global AIDS Strategy 2021-2026 identifies adolescent girls and young women (AGYW) as a priority population for HIV prevention, and recommends differentiating intervention portfolios ...geographically based on local HIV incidence and individual risk behaviours. We estimated prevalence of HIV risk behaviours and associated HIV incidence at health district level among AGYW living in 13 countries in sub-Saharan Africa. We analysed 46 geospatially-referenced national household surveys conducted between 1999-2018 across 13 high HIV burden countries in sub-Saharan Africa. Female survey respondents aged 15-29 years were classified into four risk groups (not sexually active, cohabiting, non-regular or multiple partners and female sex workers FSW) based on reported sexual behaviour. We used a Bayesian spatio-temporal multinomial regression model to estimate the proportion of AGYW in each risk group stratified by district, year, and five-year age group. Using subnational estimates of HIV prevalence and incidence produced by countries with support from UNAIDS, we estimated new HIV infections in each risk group by district and age group. We then assessed the efficiency of prioritising interventions according to risk group. Data consisted of 274,970 female survey respondents aged 15-29. Among women aged 20-29, cohabiting (63.1%) was more common in eastern Africa than non-regular or multiple partner(s) (21.3%), while in southern countries non-regular or multiple partner(s) (58.9%) were more common than cohabiting (23.4%). Risk group proportions varied substantially across age groups (65.9% of total variation explained), countries (20.9%), and between districts within each country (11.3%), but changed little over time (0.9%). Prioritisation based on behavioural risk, in combination with location- and age-based prioritisation, reduced the proportion of population required to be reached in order to find half of all expected new infections from 19.4% to 10.6%. FSW were 1.3% of the population but 10.6% of all expected new infections. Our risk group estimates provide data for HIV programmes to set targets and implement differentiated prevention strategies outlined in the Global AIDS Strategy. Successfully implementing this approach would result in more efficiently reaching substantially more of those at risk for infections.
A recent study showed how geospatial mapping can be used to improve Lesotho's HIV treatment program to achieve the 90-90-90 targets set by the United Nations but incorrectly describes "treatment as ...prevention" as the UN's strategy for a successful national AIDS response.
Since 2004, the US President's Emergency Plan for AIDS Relief (PEPFAR) has supported the tremendous scale-up of HIV prevention, care and treatment services, primarily in sub-Saharan Africa. We ...evaluate the impact of antiretroviral treatment (ART), prevention of mother-to-child transmission (PMTCT) and voluntary medical male circumcision (VMMC) programmes on survival, mortality, new infections and the number of orphans from 2004 to 2013 in 16 PEPFAR countries in Africa.
PEPFAR indicators tracking the number of persons receiving ART for their own health, ART regimens for PMTCT and biomedical prevention of HIV through VMMC were collected across 16 PEPFAR countries. To estimate the impact of PEPFAR programmes for ART, PMTCT and VMMC, we compared the current scenario of PEPFAR-supported interventions to a counterfactual scenario without PEPFAR, and assessed the number of life years gained (LYG), number of orphans averted and HIV infections averted. Mathematical modelling was conducted using the SPECTRUM modelling suite V.5.03.
From 2004 to 2013, PEPFAR programmes provided support for a cumulative number of 24 565 127 adults and children on ART, 4 154 878 medical male circumcisions, and ART for PMTCT among 4 154 478 pregnant women in 16 PEPFAR countries. Based on findings from the model, these efforts have helped avert 2.9 million HIV infections in the same period. During 2004-2013, PEPFAR ART programmes alone helped avert almost 9 million orphans in 16 PEPFAR countries and resulted in 11.6 million LYG.
Modelling results suggest that the rapid scale-up of PEPFAR-funded ART, PMTCT and VMMC programmes in Africa during 2004-2013 led to substantially fewer new HIV infections and orphaned children during that time and longer lives among people living with HIV. Our estimates do not account for the impact of the PEPFAR-funded non-biomedical interventions such as behavioural and structural interventions included in the comprehensive HIV prevention, care and treatment strategy used by PEPFAR countries. Therefore, the number of HIV infections and orphans averted and LYG may be underestimated by these models.
PDF
