This study reports the socioeconomic inequalities, trends, and the changes in age-standardized DALY rates due to HIV/AIDS from 2000 to 2019. Our study found a substantial reduction in the global burden of HIV/AIDS over time, especially in low- and middle-income countries. The most pronounced decrease in HIV/AIDS burden over this period occurred in sub-Saharan Africa, while the burden increased in certain Eastern European and the American countries. While the socioeconomic-related inequalities of HIV/AIDS burden reduced globally, an important finding of our study is that progress was skewed, with burden continuing to weigh more heavily in socioeconomically disadvantaged countries/territories. Socioeconomic inequalities of HIV/AIDS burden evolved through four phases, mirroring the uneven development of HIV prevention and control programs globally over the past two decades.
Our study confirmed a decrease in the age-standardized DALY rates of HIV/AIDS in most countries or territories worldwide (a remarkable achievement) with global trends indicating considerable progress in curbing the HIV/AIDS pandemic over the past two decades. This trend was consistent with the sustained declines in HIV/AIDS incidence and mortality globally since 2005 [7, 8, 11], and with health system reforms undertaken to enhance access to and coverage of health care [25]. The reduced global burden of HIV/AIDS was attributed to a combination of efforts, including more effective prevention and control strategies as well as better treatment interventions, such as poverty alleviation, improvement of healthcare access, intensified international collaborations, health education, and other proximal ongoing contributions [5]. Within the Millennium Development Goals launched by the World Health Organization (WHO) in 2000, HIV/AIDS was established as a top global health priority and received substantial health resources and international financing [4, 5, 26]. A few major international organizations and foundations specializing in combating HIV/AIDS were expanded or initiated, with substantial funding provided annually to deliver HIV-related prevention, treatment, and financing protection services for regions struggling with a critical HIV epidemic [5]. The total assistance for HIV prevention was estimated at $22.7 billion from 1990 to 2015 [5], with a focus on assisting low-income countries. The funding has been committed to controlling HIV transmission, including eliminating mother-to-child transmission (through prenatal HIV testing, at-birth prevention, and safe breastfeeding guidelines), eliminating blood transmission (through donated blood testing), and controlling sexual and injecting drug transmission (through condom use, couples counseling and testing, pre-exposure prophylaxis (PrEP), needle exchange program, and an opioid substitution program) [3, 27]. In addition, HIV education, healthy lifestyle behaviors, and mental support services have a lasting positive impact on reducing HIV incidence worldwide [27, 28]. ART was vital for long-term HIV suppression, transforming AIDS from a fatal infection to a treatable chronic disease [3]. The WHO had endorsed a series of resolutions to promote access to ART in developing countries since 2000, aiming to reduce mortality and improve the quality of life of people living with HIV [29–31]. China initiated the free ART program in 2002 as a positive response to combat HIV/AIDS [32]. Sustained efforts have yielded solid progress, and an estimated 75% of people living with HIV globally were receiving ART in 2021 [2]. Prevention and ART were therefore of major significance in alleviating the global burden of HIV/AIDS.
Despite the fact that sub-Saharan Africa remains the epicenter of the HIV pandemic [8, 10], it is encouraging that the HIV/AIDS burden has declined significantly over the past two decades. Much of the progress against HIV/AIDS in sub-Saharan African countries, including Burundi, Malawi, and Zimbabwe, may be attributable to increased health investments, improved healthcare systems, secondary and tertiary education, HIV self-testing programs, and adolescent male circumcision [33–36]. Furthermore, the “treat all” policy efficiently promoted the rapid initiation of ART in six sub-Saharan African countries from 2004 to 2018 [37]. However, the burden clearly increased in certain Eastern European and the American countries, concurring with a study by Govender et al. which indicated an increasing incidence of HIV/AIDS in these countries [38]. Weakened public health programs, reduction in health funding, men who have sex with men (MSM), and the spread of drug-resistant HIV strains are possible explanatory factors in this concerning finding [39–41].
We discovered that countries with a low GNI per capita were sharing an overwhelming burden of HIV/AIDS, though the global inequality has reduced over time. In previous studies, the total burden of HIV/AIDS, including both incidence and mortality, was heavier in most low and middle-income countries than in high-income ones [7, 8, 11]. It is widely acknowledged that income is a core social determinant in human health [42], and its distributional inequalities and imbalances may exert a substantially adverse impact on health financing, access to healthcare, health insurance coverage, access to education, and health outcomes [43]. Globally, total expenditure on HIV/AIDS has increased annually since 2000, but was concentrated in high-income countries, leaving governments of low-income countries struggling to prioritize the prevention and control of HIV/AIDS due to a dearth of health funding [39]. In this context, owing to the absence of primary care infrastructures, persons living with HIV and at-risk populations from low-income countries such as those in sub-Saharan Africa failed to benefit from sufficient healthcare services, including timely HIV testing, mother-to-child program enrollment, and sustained ART treatment. This contrasts with improved quality of HIV care in high-income industrialized countries, such as the introduction of highly active antiretroviral treatment (HAART), which minimized viral replication levels via a combination of several efficacious antiretrovirals, leading to a striking decline in HIV incidence and mortality [3]. Health insurance has been found to be significantly associated with socioeconomic status, and to effectively enhance access to health care for HIV/AIDS and reduce the risk of HIV transmission [44], as well as delivering financial protection from catastrophic health expenditures. People living with HIV in high-income countries are primarily covered by social health insurance, Medicaid, private medical insurance, or a combination of these coverages [45], which provide free ART coverage and health counseling services to maintain continuity of patients’ healthcare [44]. However, a lack of universal health insurance coverage in most low-income countries accounts for the vulnerable health financing mechanisms [46], may result in people with HIV/AIDS declining treatment in response to persistent out-of-pocket expenditures, thus contributing to increased mortality. The socioeconomic status of a country has been found to yield synergy with education coverage, which in turn is highly correlated with HIV awareness, preventive measures, transmission risk, and reduced stigma and discrimination against people with HIV/AIDS [12]. Among countries with low socioeconomic status, limited education hampered the access to HIV care and diminished the readiness of the stigmatized populations to seek care [12]. Additionally, gender and racial inequalities were more prevalent in low-income countries, and women and people of color with HIV/AIDS were more exposed to denial of sexual and reproductive health rights, reducing their access to HIV-related medical care [47, 48]. HIV/AIDS is prone to a variety of complications as it destroys the immune system of infected individuals, resulting in greater costs of care [3]. Consistent with this, people living with HIV in low-income countries are more likely to undergo disease progression and deterioration due to the unaffordable cost of complications.
Our discovery of significantly reducing socioeconomic inequalities in HIV/AIDS burden between countries over time is encouraging, and mirrors the natural history of the HIV pandemic and the valid implementations of related strategies. This improving trend signifies the advances of the regional reduction: at lower socioeconomic class, HIV/AIDS burden is relatively heavy, and its decrease over time is greater. Consistent with this, the concentration curves tend towards equality (the diagonal) over time, indicating a narrowing gap in HIV/AIDS burden between low- and high-income countries, particularly in the periods 2000–2002 and 2007–2016, though the trend was modest. The accomplishments of inequality reduction in both periods are attributable primarily to the continuing support of international assistance organization [5]. However, our study found a slight, insignificant rise in inequality of the global HIV/AIDS burden in the period 2002–2007. One possible explanation for this finding is that developed countries were more capable of tackling the HIV pandemic and delivering an early response based on an already robust health system. We also found that the global campaign to tackle the unequal burden of HIV/AIDS from 2016 to 2019 was stagnant, a cautionary signal for global health.
Our analysis of cross-national socioeconomic inequality of HIV/AIDS burden is beneficial in illustrating global patterns of HIV inequality, which may contribute to policy and strategy development worldwide. Sustained efforts to combat the HIV pandemic over the past two decades have resulted in progress toward reducing the overall global burden of HIV/AIDS. However, slow progress was made in addressing the socioeconomic-related inequalities in the HIV/AIDS burden and related morbidity and mortality, and no substantial strides in HIV-related intervention strategies have been made in recent years, implying that many countries are unlikely to realize UNAIDS 2030 morbidity and mortality targets [8]. With increased life expectancy, the number of people living with HIV is growing, and HIV carriers are at high risk of COVID-19 complications [49], which continue to place an increasing burden on health systems, particularly in low-income countries. Further expansion of health assistance for low- and middle-income countries is urgently warranted to accelerate the pace of progress. Early diagnosis and intervention are regarded as the most cost-effective strategies [50], especially for regions with restricted health resources. These approaches should be combined with enhanced education, disease awareness and protection, in an effort to avert or reduce the adverse health consequences of HIV, and this demands collaborative cross-sectoral actions targeting the social determinants of health. Thus, as a protective HIV vaccine is not available, further consolidation and upscaled HIV surveillance and testing, risk consultation, PrEP and ART access, and other support programs are crucial. From a high-risk population perspective, there is a compelling need for the HIV/AIDS response to focus on women in regions with high-endemic poverty, who are exposed to the most profound inequalities in HIV/AIDS care, including stigma, denial of treatment, and violence [6]. HIV is more than a medical condition, and concerns human rights. Targeted interventions should surpass HIV suppression and provide full consideration of the social, economic, legal, psychological and emotional demands in combating the HIV pandemic. Drawing on the evidence and experience obtained over the past two decades, a multi-pronged, multi-tiered strategy is needed to minimize HIV inequality across countries and to end the HIV pandemic.
Strengths and Limitations
A strength of the current study is the comprehensive population-based assessment and comparison of trends in socioeconomic inequalities of HIV/AIDS burden worldwide based on nations’ income levels, which adds to the evidence base for the development and implementation of future HIV inequality-eradication strategies. Several limitations should be considered. First, as with other GBD analyses, the accuracy of estimates in our study depend on the quality and quantity of data sources. These were limited by detection techniques, incomplete case-reports, and data collection and encoding methods used in different countries. Second, the absence of epidemiological surveys in certain regions may result in a hidden incidence, particularly in low-income countries, which means that inequality of HIV/AIDS burden is potentially underestimated. Finally, our study is cross-national, which may introduce bias due to a lack of knowledge of disparities that exist between districts within countries.