HIV Prevention Strategies Require Wide-scale Changes to Ensure Mortality Rates Continue to Decrease

Although several ambitious initiatives intended to put an end to the AIDS epidemic have been developed and implemented, this laudable goal will be difficult to achieve without substantial and wide-scale changes in HIV prevention strategies, according to the results of a study published recently in Lancet HIV.¹

The Joint United Nations Programme on HIV/AIDS (UNAIDS) has called for 90% of people living with HIV to know their status, 90% of those known to have HIV treated with antiretroviral therapy (ART), and 90% of those on ART achieving viral load suppression by the year 2030.² Sustainable Development Goal 3 also calls for an end to the epidemic by 2030. The results from the equally ambitious Worldwide, Millennium Development Goal 6, intended to provide universal access to treatment and stop/reverse the spread of HIV by 2015, have been discouraging.³

The Global Burden of Disease (GBD) and UNAIDS both provide comparable global and country level evaluations of trends in the HIV/AIDS epidemic. As part of these efforts, UNAIDS developed and subsequently employed two epidemiological programs, the Estimation and Projection Package (EPP), and Spectrum, each designed to estimate HIV incidence, prevalence, and mortality.

Although UNAIDS and GBD estimates are converging at the global level,⁴ their local estimates differ. These disparities, noted by first author Haidong Wang, PhD, an Assistant Professor of Global Health at the Institute for Health Metrics and Evaluation at the University of Washington in Seattle, and his colleagues were part of the rationale for their study. The authors stated, "Nevertheless, estimates differ substantially in several countries, particularly in middle-income and high-income countries, where GBD estimates are based on data from vital registration systems and UNAIDS estimates are based on prevalence in high-risk groups and estimates of the fraction of the population in these groups."

To address these disparities, Dr. Wang and his colleagues updated their previously published GBD document (GBD 2013)³ by systematically revising their key inputs with the intention of improving on the estimation procedures originally developed by UNAIDS. Vital registration systems and population health survey data were both included in order to measure seroprevalence. Additionally, the provision of internal consistency allowed for the integration of the GBD HIV/AIDS estimation process and the all-cause mortality estimation processes of the EPP and Spectrum, linking and improving the process as a whole. Furthermore, a cohort incidence bias adjustment process was developed to provide consistency between the Spectrum incidence and prevalence estimates and the vital registration system-derived HIV mortality estimates, when available. Lastly, on-ART mortality rates were updated using an expanded literature search.

The updated document is comprehensive and includes copious amounts of data. The results that the authors were most interested in conveying were that the global incidence HIV reached its peak in 1997 (3.3 million new infections), the annual incidence stayed relatively constant (approximately 2.6 million per year) since 2005, and that the population living with HIV/AIDS has been growing steadily (38.8 million in 2015). Additional important results showed that HIV/AIDS mortality decreased steadily from 1.8 million deaths to 1.2 million deaths in 2005 and 2015, respectively. Country-based data varied widely, with some countries showing decreased mortality attributable to HIV/AIDS, as well as lower rates of annual new infections, while others showed a slowing of rates of change in annual new infections. Increased rates were also noted.

In describing their interpretation of the study data, the GBD 2015 HIV Collaborators stated, "This report from GBD 2015 provides a unique perspective on the national-level epidemiology of HIV/AIDS, which includes a comprehensive assessment of HIV/AIDS incidence, prevalence, and deaths." They also concluded that, "Improving on existing models of HIV/AIDS burden estimates, this study provides the most comprehensive and internally consistent assessments of the levels and trends of HIV/AIDS incidence, prevalence, and mortality worldwide so far."

Regarding the broader implications of the study results, the authors stated, "This timely report provides much needed assessment of achievement of Millennium Development Goal 6, and lays out the challenges facing the global community in progress towards the HIV goals enshrined in Sustainable Development Goal 3 and the 90—90–90 UNAIDS targets."

William Perlman, PhD, CMPP is a former research scientist currently working as a medical/scientific content development specialist. He earned his BA in Psychology from Johns Hopkins University, his PhD in Neuroscience at UCLA, and completed three years of postdoctoral fellowship in the Neuropathology Section of the Clinical Brain Disorders Branch of the National Institute of Mental Health.

References

1. Wang H, Wolock TM, Carter A, et al. Estimates of global, regional, and national incidence, prevalence, and mortality of HIV, 1980—2015: the Global Burden of Disease Study 2015. Lancet HIV 2016;3:e361–e87.
2. UNAIDS. 90—90–90—an ambitious treatment target to help end the AIDS epidemic. Oct 8, 2014. http://www.unaids.org/en/resources/documents/2014/90-90-90 (accessed July 7, 2016).
3. Murray CJL, Ortblad KF, Guinovart C, et al. Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990—2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2014 384:1005–1070.
4. Ortblad KF, Lozano R, Murray CJL. The burden of HIV: insights from the Global Burden of Disease Study 2010. AIDS Lond Engl 2013;27:2003—2017.