Noncommunicable Diseases: Yet Another Challenge for Human Immunodeficiency Virus Treatment and Care in Sub-Saharan Africa

(See the Major Article by Smit et al on pages 1864–73.) As the fourth year of universal test and treat gets under way, 67% of all people living with human immunodeficiency virus (HIV) infection (PLWH) in eastern and southern Africa have obtained antiretroviral therapy (ART), while consequently AIDS and HIV-related mortality rates continue to decline [1]. Many sub-Saharan African (SSA) countries have made progress toward achieving the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 goals by 2020 including Kenya, where according to UNAIDS 2018 estimates 89% of PLWH were diagnosed, and of these, 69% were on ART [1]. Over time, SSA HIV treatment and care programs have transitioned from an emergent health response to more chronic disease management. A growing concern is that even among PLWH on ART, the risks for many noncommunicable diseases (NCDs) such as cardiovascular disease, cancer, and kidney disease appear to be increased, due in part to ongoing inflammation and immune activation [2, 3]. The NCD burden in SSA is higher than the global average [4] and reported to be higher among PLWH [5, 6]. While some studies of specific NCDs in SSA have not implicated HIV as a specific risk factor and suggested that other key risk factors may differ by HIV status [7], there is growing concern that weight gain associated with dolutegravir-containing first-line regimens could contribute to metabolic disorders, another risk factor for many NCDs [8]. The intersection of HIV and NCDs (“syndemic”) is increasingly recognized as a challenge for PLWH and the health systems caring for them. High-quality, population-based epidemiological data are essential to understanding relevant NCD risk factors and developing targeted prevention and control efforts [5]. Development of population models can inform public health policy and help identify potential approaches to disease mitigation. In this issue of Clinical Infectious Diseases, Smit and colleagues present a multidisease modeling study to estimate the burden of several NCDs in Kenya through 2035, stratified by HIV status [9]. The results support growing concerns about NCDs in Kenya and SSA. To inform model parameters, the authors also systematically reviewed and meta-analyzed NCD data from Kenya. This study will undoubtedly provide a resource of interest for many in the field as this syndemic unfolds. In contrast with other recent reports [6, 7], the authors estimate that more than half of the Kenyan adult population is currently affected by at least 1 NCD, with PLWH more affected. While NCD prevalence was projected to increase modestly through 2035, the total number affected was projected to nearly double during this time, primarily due to population growth, although population aging was also a relevant factor, especially among PLWH. Rural health data are scant, especially for countries with large rural populations such as Kenya, and for several NCDs in the present study, few or no country-specific data were available. Therefore, beyond providing insights about NCDs in this setting, the work highlights where further research is needed. Most epidemiologic data are from North American and European cohorts, which are unable to account for differences in NCD risk by African region/country or consider context-specific risk factors such as body mass index or environmental exposures. Several African population-based cohort studies are being developed to fill these gaps, for example, in sites supported by the US President’s Emergency Plan for AIDS Relief (PEPFAR) [6], and should continue to be leveraged. An additional difficulty in many SSA care settings is the lack of standardized screening practices for NCDs [5]. Given the potential health and economic benefits for both patients and the healthcare system over the long term, there is a pressing need for SSA country-specific and regional healthcare guidelines to incorporate NCD screening and management [5, 7]. Over the past 15 years as ART rollout in SSA prompted infrastructure improvements, the focus of HIV care and ART programs broadened to assume other communicable, maternal, neonatal, and nutritional (CMNN) diseases. The success of this integrated care model in reducing these is shown by the NCD burden now being almost equivalent to CMNN diseases and expected to overtake these in causing disability and mortality over the next 20 years [4, 10]. Smit et al raise another prescient concern in this regard. An enormous investment in healthcare infrastructure for HIV testing, diagnosis, linkage and treatment has resulted in a dramatic reversal of AIDS-related mortality with a mounting proportion of PLWH remaining in care. However, the expanding patient population presents challenges to the existing infrastructure in many SSA settings [10]. Simultaneously, recognition of developing disparities in healthcare between those with or without HIV infection has begun to raise questions about broadening the scope of current HIV care services to include uninfected persons. Without commitment from local ministries of health to invest in the comprehensive care and monitoring model, improved healthcare infrastructure, advancement of validated guidelines and algorithms, and/or system modification, the addition of NCD screening and management requirements and expansion of the population in care present daunting challenges. Creative responses such as decentralized care, integrated horizontal care models, telehealth, and trained advanced practice, nursing, and community providers have shown promise in this regard [10]. Further studies and investment, including establishment of sponsorship for procurement and provision of NCD treatment medications, are needed to identify best practices and ensure provision of high-quality healthcare to all those in need. As with any modeling study, data may be incomplete for some known risk factors and simplifying assumptions may impact estimates; assumptions about the impact of risk factors on disease occurrence and outcomes require evaluation in such varied settings. The authors note that some specific risk factor data were lacking, so their model did not incorporate known individual-level NCD risk factors such as smoking, alcohol, or diet; instead the risk of these was modeled as uniformly distributed in the population. They noted that this may result in overestimation of population NCD rates if such lifestyle issues are more focal. New HIV infection rates were modeled as stable after 2017; however, these have declined for years, including from 2017 to 2018 [1], and would be expected to continue to slowly decline as ART use increases. This may overestimate the total number of PLWH in 2035 and the resulting additional HIV-related NCDs. While the authors’ model closely recapitulates the Kenyan population from 1950 to 2015 and is similar to projections to 2035, the current adult NCD prevalence estimate is notably high (51% of HIV-uninfected persons and 62% of PLWH with ≥1 NCD) and differs from that among 2920 participants enrolled in PEPFAR-supported clinics (79% PLWH) from 4 African countries including Kenya where 37.7% of participants had ≥1 NCD [6], as well as from a retrospective nationally representative survey of health records for PLWH enrolled in care that showed 11.5% prevalence of 4 NCDs [7]. However, the populations under study and the NCDs considered differ among these studies. For example, the current report includes depression, although the estimated prevalence of 3.4% is lower than that from others [5] and would not greatly increase the overall NCD estimates. Another meta-analysis of NCDs in low- and middle-income countries produced pooled prevalence estimates of 21.2% for hypertension and 22.2% for hyperlipidemia [5], similar to the 20.5% estimate for hypertension in the present report, but significantly higher than 9.0% estimate for hyperlipidemia. While there remains uncertainty in the absolute levels of NCD prevalence in the Kenyan and SSA HIV-positive and -negative populations, there is little doubt that NCDs are a significant and growing health concern requiring concerted efforts toward understanding local and regional drivers and prevention and control in the coming years. These will challenge healthcare systems and necessitate creative, locally relevant care and resourcing solutions. Disclaimer. The views expressed are those of the authors and do not necessarily reflect the official views or policies of the Uniformed Services University of the Health Sciences, the US Department of Defense or the Departments of the Army, Navy, or Air Force, the National Institutes of Health, the Department of Health and Human Services, the Department of Veterans Affairs, or the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. Mention of trade names, commercial products, or organizations does not imply endorsement by the US government. Financial support. This work was conducted by the Infectious Disease Clinical Research Program, a Department of Defense program executed by the Uniformed Services University of the Health Sciences through a cooperative agreement with the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. This project has been supported in whole, or in part, with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, under Interagency Agreement Y1-AI-5072. V. C. M. received support from the National Institute of Allergy and Infectious Diseases, National Institutes of Health (R01 AI098558) and the Emory University Center for AIDS Research (P30AI050409) and reports employment through the Atlanta Veterans Affairs Medical Center. Potential conflicts of interest.