Introduction
A recent sero‐discordant couple study showed an elevated risk of HIV‐acquisition during the pregnancy/postpartum period per‐condomless‐coital‐act. This, along with previous studies, has ...led to concern over possible increased risk of mother‐to‐child (vertical) transmission, due to the initial high viral load in the first months after seroconversion, in a time when the woman and health services may be unaware of her status. This study looks at whether behavioural differences during the pregnant/postpartum period could reduce the impact of elevated risk of HIV acquisition per‐condomless‐coital‐act at the population level.
Methods
We used data from 60 demographic and health surveys from 32 sub‐Saharan African countries. Using the HIV status of couples, we estimated differences in serodiscordancy between HIV‐negative women who were pregnant/postpartum compared to those who were not pregnant/postpartum. We compare the risk of sexual activity over the pregnant/postpartum period to those not pregnant/postpartum. Using these risks of serodiscordancy and sexual activity along with estimates of increased HIV risk in the pregnancy/postpartum period per‐condomless‐coital‐act, we estimated a population‐level risk of HIV acquisition and acute infection, during pregnancy/postpartum compared to those not pregnant/postpartum.
Results
Sexual activity during pregnancy/postpartum varies considerably. In general, sexual activity is high in the first trimester of pregnancy, then declines to levels lower than among women not pregnant/postpartum, and is at its lowest in the first months postpartum. Adjusted for age and survey, pooled results show HIV‐negative pregnant women are less likely to have an HIV‐positive partner compared to those not pregnant/postpartum (risk ratio (RR) = 0.78, 95% CI = 0.68–0.89) and comparing the postpartum period (RR = 0.85, 95% CI = 0.73–0.99). Estimated population‐level risk for HIV acquisition and acute infection in pregnancy/postpartum was lower than would be inferred directly from per‐condomless‐coital‐act estimates in most countries, over the time of most risk of mother‐to‐child transmission, though there was variation by country and month of pregnancy/postpartum.
Conclusions
Estimates of population‐level HIV acquisition risk in sub‐Saharan Africa should not be taken directly from per‐condomless‐coital‐act studies to estimate vertical transmission. Changes in sexual behaviour and differences in HIV‐serodiscordancy during pregnancy/postpartum reduce the impact of increased risk of HIV acquisition per‐condomless‐coital‐act, this will vary by region.
Introduction
Over the past 20 years, the response to the HIV epidemic has achieved remarkable results. These results have often been motivated by targets adopted by countries through United Nations ...(UN) Political Declarations on HIV. The 2016 political declaration included two impact targets, to achieve a 75% decline in new HIV infections and AIDS‐related deaths between 2010 and 2020, and to reach the 90‐90‐90 testing and treatment targets by 2020. Our objective is to summarize progress towards these targets using robust and comparable HIV estimates released by UNAIDS in July 2021. In addition, we comment on the importance of targets and the modelled estimates required to quantify those targets.
Discussion
The UNAIDS estimates indicate that at the global and regional levels, the 2020 targets were missed: new infections declined by 31% and AIDS‐related deaths declined by 47% between 2010 and 2020, compared to a target of 75% decline for both indicators. Similarly, no region achieved the 90‐90‐90 testing and treatment targets. Some countries, in diverse settings, achieved these targets showing that the targets were not overly ambitious if the right funding, policies and evidence‐informed interventions at the right scale were in place. The 2021 UN Political Declaration on HIV, adopted on 8 June 2021, has set out a new set of ambitious but achievable targets for 2025. The 2025 targets and the required actions to reach those targets are described in the Global AIDS Strategy 2021–2026, which provides a framework to reprioritize HIV responses by reducing inequalities and building on the achievements of multiple Sustainable Development Goals. The Strategy encourages countries to monitor progress against targets for different geographic areas and populations to maximize equitable services and ensure accountability and also to understand why targets are being missed.
Conclusions
The UNAIDS epidemiological estimates provide information that promote accountability and estimate progress towards global targets at the national level. Additional strategic information and analyses are required to identify the populations that are furthest from the targets and the programmes and policies that are keeping countries from meeting their targets.
Breastfeeding improves child survival but is a source of mother-to-child HIV transmission among women with unsuppressed HIV infection. Estimated HIV incidence in children is sensitive to ...breastfeeding duration among mothers living with HIV (MLHIV). Breastfeeding duration may vary according to maternal HIV status.
Sub-Saharan Africa.
We analyzed pooled data from nationally representative household surveys conducted during 2003-2019 that included HIV testing and elicited breastfeeding practices. We fitted survival models of breastfeeding duration by country, year, and maternal HIV status for 4 sub-Saharan African regions (Eastern, Central, Southern, and Western).
Data were obtained from 65 surveys in 31 countries. In 2010, breastfeeding in the first month of life ("initial breastfeeding") among MLHIV ranged from 69.1% (95% credible interval: 68-79.9) in Southern Africa to 93.4% (92.7-98.0) in Western Africa. Median breastfeeding duration among MLHIV was the shortest in Southern Africa at 15.6 (14.2-16.3) months and the longest in Eastern Africa at 22.0 (21.7-22.5) months. By comparison, HIV-negative mothers were more likely to breastfeed initially (91.0%-98.7% across regions) and for longer duration (median 18.3-24.6 months across regions). Initial breastfeeding and median breastfeeding duration decreased during 2005-2015 in most regions and did not increase in any region regardless of maternal HIV status.
MLHIV in sub-Saharan Africa are less likely to breastfeed initially and stop breastfeeding sooner than HIV-negative mothers. Since 2020, UNAIDS-supported HIV estimates have accounted for this shorter breastfeeding exposure among HIV-exposed children. MLHIV need support to enable optimal breastfeeding practices and to adhere to antiretroviral therapy for HIV treatment and prevention of postnatal mother-to-child transmission.
Introduction
HIV planning requires granular estimates for the number of people living with HIV (PLHIV), antiretroviral treatment (ART) coverage and unmet need, and new HIV infections by district, or ...equivalent subnational administrative level. We developed a Bayesian small‐area estimation model, called Naomi, to estimate these quantities stratified by subnational administrative units, sex, and five‐year age groups.
Methods
Small‐area regressions for HIV prevalence, ART coverage and HIV incidence were jointly calibrated using subnational household survey data on all three indicators, routine antenatal service delivery data on HIV prevalence and ART coverage among pregnant women, and service delivery data on the number of PLHIV receiving ART. Incidence was modelled by district‐level HIV prevalence and ART coverage. Model outputs of counts and rates for each indicator were aggregated to multiple geographic and demographic stratifications of interest. The model was estimated in an empirical Bayes framework, furnishing probabilistic uncertainty ranges for all output indicators. Example results were presented using data from Malawi during 2016–2018.
Results
Adult HIV prevalence in September 2018 ranged from 3.2% to 17.1% across Malawi's districts and was higher in southern districts and in metropolitan areas. ART coverage was more homogenous, ranging from 75% to 82%. The largest number of PLHIV was among ages 35 to 39 for both women and men, while the most untreated PLHIV were among ages 25 to 29 for women and 30 to 34 for men. Relative uncertainty was larger for the untreated PLHIV than the number on ART or total PLHIV. Among clients receiving ART at facilities in Lilongwe city, an estimated 71% (95% CI, 61% to 79%) resided in Lilongwe city, 20% (14% to 27%) in Lilongwe district outside the metropolis, and 9% (6% to 12%) in neighbouring Dowa district. Thirty‐eight percent (26% to 50%) of Lilongwe rural residents and 39% (27% to 50%) of Dowa residents received treatment at facilities in Lilongwe city.
Conclusions
The Naomi model synthesizes multiple subnational data sources to furnish estimates of key indicators for HIV programme planning, resource allocation, and target setting. Further model development to meet evolving HIV policy priorities and programme need should be accompanied by continued strengthening and understanding of routine health system data.
To examine levels and patterns of HIV prevalence, knowledge, sexual behavior, and coverage of selected HIV services among adolescents aged 10-19 years and highlight data gaps and challenges.
Data ...were reviewed from Joint United Nations Programme on HIV/AIDS HIV estimates, nationally representative household surveys, behavioral surveillance surveys, and published literature.
A number of gaps exist for adolescent-specific HIV-related data; however, important implications for programming can be drawn. Eighty-two percent of the estimated 2.1 million adolescents aged 10-19 years living with HIV in 2012 were in sub-Saharan Africa, and the majority of these (58%) were females. Comprehensive accurate knowledge about HIV, condom use, HIV testing, and antiretroviral treatment coverage remain low in most countries. Early sexual debut (sex before 15 years of age) is more common among adolescent girls than boys in low- and middle-income countries, consistent with early marriage and early childbirth in these countries. In low and concentrated epidemic countries, HIV prevalence is highest among key populations.
Although the available HIV-related data on adolescents are limited, increased HIV vulnerability in the second decade of life is evident in the data. Improving data gathering, analysis, and reporting systems specific to adolescents is essential to monitoring progress and improving health outcomes for adolescents. More systematic and better quality disaggregated data are needed to understand differences by sex, age, geography, and socioeconomic factors and to address equity and human rights obligations, especially for key populations.
Global targets call for a 75% reduction in new HIV infections and AIDS deaths between 2010 and 2020. UNAIDS supports countries to measure progress towards these targets. In 2019, this effort resulted ...in revised national, regional and global estimates reflecting the best available data.
Spectrum software was used to develop estimates for 170 countries. Country teams from 151 countries developed HIV estimates directly and estimates for an additional 19 country were developed by UNAIDS based on available evidence. 107 countries employed models using HIV prevalence data from sentinel surveillance, routinely collected HIV testing and household surveys while the remaining 63 countries applied models using HIV case surveillance and/or reported AIDS deaths. Model parameters were informed by the UNAIDS Reference Group on Estimates, Modeling and Projections.
HIV estimates were available for 170 countries representing 99% of the global population. An estimated 37.9 million (uncertainty bounds 32.7-44.0 million) people were living with HIV in 2018. There were 1.7 million (1.4-2.3 million) new infections and 770 000 (570 000-1.1 million) AIDS-related deaths. New HIV infections declined in five of eight regions and AIDS deaths were declining in six of eight regions between 2010 and 2018.
The estimates demonstrate progress towards ending the AIDS epidemic by 2030, however, through 2018 declines in new HIV infections and AIDS-related deaths were not sufficient to meet global interim targets. The UNAIDS estimates have made important contributions to guide decisions about the HIV response at global, regional and country level.
In 2014, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and partners set the 90-90-90 target for the year 2020: diagnose 90% of all people living with HIV (PLHIV); treat 90% of people who ...know their status; and suppress the virus in 90% of people on treatment. In 2015, countries began reporting to UNAIDS on progress against 90-90-90 using standard definitions and methods.
We used data submitted to UNAIDS from 170 countries to assess country-specific progress towards 90-90-90 through 2018. To assess global and regional progress, overall and by sex for adults aged 15 years and older, we combined country-reported data with estimates generated with a Bayesian hierarchical model.
A total of 60 countries reported on all three 90s in 2018, up from 23 in 2015. Among all PLHIV worldwide, 79% (67-92%) knew their HIV status. Of these, 78% (69-82%) were accessing treatment and 86% (72-92%) of people accessing treatment had suppressed viral loads. Of the 37.9 million (32.7-44.0 million) PLHIV worldwide, 53% (43-63%) had suppressed viral loads. The gap to fully achieving 73% of PLHIV with suppressed viral load was 7.7 million; 15 countries had already achieved this target by 2018.
Increased data availability has led to improved measures of country and global progress towards the 90-90-90 target. Although gains in access to testing and treatment continue, many countries and regions are unlikely to reach the 90-90-90 target by 2020.
Children who are HIV-exposed uninfected (HEU) have higher morbidity and mortality than children who are HIV-unexposed and uninfected despite safer breastfeeding and improved maternal health with ...maternal antiretroviral therapy. We present the first global estimates of the population of children who are HEU (aged 0–14 years) and the geographical and temporal trends in HIV high-burden countries between 2000 and 2018.
The Spectrum AIDS Impact Module developed by Avenir Health, UNAIDS, and partners is used to estimate key HIV epidemic indicators from mathematical models. We used 2019 UNAIDS global estimates of children (aged 0–14 years) who are HEU generated by Spectrum and 2017 UN Population Division estimates of the number of all children in each region or country to estimate the regional or national prevalence of children who were HEU, the regional or national contribution of children who were HEU to the global population of children who were HEU, and the proportion of children who were HEU and exposed to antiretrovirals for six UNAIDS regions and 21 HIV high-burden countries in 2018. We also estimated the percentage change in the global population of children who were HEU between 2000 and 2018.
In 2018, there were an estimated 14·8 million (lower estimate 11·1–upper estimate 18·3) children who were HEU, 13·2 million (9·8–16·3; 90%) of whom resided in sub-Saharan Africa and 760 000 (640 000–970 000; 5%) of whom resided in the Asia and Pacific region. Five countries accounted for 50% of all 14·8 million children who were HEU globally: South Africa (3·5 million 23·8%), Uganda (1·1 million 7·5%), Mozambique (1·0 million 6·6%), Tanzania (910 000 6·1%); and Nigeria (880 000 6·0%). In five southern African countries, the prevalence of children who were HEU exceeded 15% of the general child population: eSwatini (32·4%), Botswana (27·4%), South Africa (21·6%), Lesotho (21·1%), and Namibia (16·4%).
The global population of children who are HEU is substantial, requiring a coordinated strategy to reduce HIV exposure in children and ensure optimal health and wellbeing of children who are HEU and their families. Future research and programmatic funding investments must be aligned with the geographical distribution of children who are HEU.
National Institutes of Health, International AIDS Society.
To present the most recent 2013 UNAIDS estimates of HIV prevalence among people aged 50 years and older, and to validate these estimates using data from national household surveys.
Modelled estimates ...of HIV prevalence were validated against nationally representative household survey measures of HIV prevalence.
The UNAIDS 2013 HIV estimates were used to compute HIV prevalence and number of people living with HIV aged 50 years and older. Sex-specific HIV-prevalence rates by the 5-year age group were calculated from nationally representative household surveys conducted between 2003 and 2013, and were compared to prevalence rates from the modelled estimates. The ratios (Spectrum/Survey) of the prevalence rates from the two sources were analysed.
In 2013, an estimated 4.2 million (4.0-4.5 million) people aged 50 years and older were living with HIV. The global HIV prevalence among older individuals more than doubled in almost all the 5-year age groups since 1995. There was a relatively good agreement between the modelled HIV-prevalence rates and the survey-based rates among men and women aged 50-54 years (0.90 and 1.00 median ratio, respectively), whereas for 55-59 year-olds, the differences were more notable (ratios of 0.63 for men and 0.90 for women).
Both data sources suggest HIV-prevalence rates among people aged over 50 have increased steadily in the recent years. Care and treatment services need to address the specific needs of older people living with HIV. Action is needed to incorporate older age groups into HIV surveillance systems.
Introduction: With increasing survival of vertically HIV‐infected children and ongoing new horizontal HIV infections, the population of adolescents (age 10–19 years) living with HIV is increasing. ...This review aims to describe the epidemiology of the adolescent HIV epidemic and the ability of national monitoring systems to measure outcomes in HIV‐infected adolescents through the adolescent transition to adulthood.
Methods: Differences in global trends between younger (age 10–14 years) and older (age 15–19 years) adolescents in key epidemic indicators are interrogated using 2016 UNAIDS estimates. National population‐based survey data in the 15 highest adolescent HIV burden countries are evaluated and examples of national case‐based surveillance systems described. Finally, we consider the potential impact of adolescent‐specific recommendations in the 2016 WHO Consolidated Guidelines on the Use of Antiretroviral Drugs for Treating and Preventing HIV Infection.
Discussion: UNAIDS estimates indicate the population of adolescents living with HIV is increasing, new HIV infections in older adolescents are declining, and while AIDS‐related deaths are beginning to decline in younger adolescents, they are still increasing in older adolescents. National population‐based surveys provide valuable estimates of HIV prevalence in older adolescents and recent surveys include data on younger adolescents. Only a few countries have nationwide electronic case‐based HIV surveillance, with the ability to provide population‐level data on key HIV outcomes in the diagnosed population living with HIV. However, in the 15 highest adolescent HIV burden countries, there are no systems tracking adolescent transition to adulthood or healthcare transition. The strength of the 2016 WHO adolescent‐specific recommendations on antiretroviral therapy and provision of HIV services to adolescents was hampered by the lack of evidence specific to this age group.
Conclusions: Progress is being made in national surveillance and global monitoring systems to specifically identify trends in adolescents living with HIV. However, HIV programmes responsive to the evolving HIV prevention and treatment needs of adolescents can be facilitated further by: data disaggregation to younger and older adolescents and mode of HIV infection where feasible; implementation of tools to achieve expanded national case‐based surveillance; streamlining consent/assent procedures in younger adolescents and consensus on indicators of adolescent healthcare transition and transition to adulthood.
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