Wealth, income and HIV in sub-Saharan Africa: a systematic review.

INTRODUCTION: While economic vulnerability is an established driver of health disparities, the relationships between HIV and wealth, income, and economic inequality have been less consistently established. We conducted a systematic review of studies examining associations between wealth, income, and economic inequality and HIV incidence and prevalence in sub-Saharan Africa (SSA). METHODS: Following PRISMA guidelines, we searched PubMed, SCOPUS, Embase, EconLit and PsycINFO for quantitative publications through June 2024 examining the relationship between wealth, income or inequality and HIV status, acquisition, prevalence or incidence in SSA. From September 2022 to October 2024, we extracted data using standardized forms, assessed risk of bias and qualitatively summarized results. RESULTS: Overall, 47 studies covering 48 countries met the inclusion criteria. Studies had generally low risk of bias, and most focused on a single country (n = 38), assessed household wealth as the exposure (n = 36) and employed cross-sectional designs (n = 33). Studies assessing wealth and HIV incidence consistently identified a protective effect, while findings around HIV incidence and income were mixed. In studies assessing HIV prevalence, findings on HIV and individual and household income or wealth were mixed. Economic inequality was consistently associated with increased HIV prevalence at community, sub-national and national levels. DISCUSSION: Most included studies were cross-sectional, among the general population, and secondary analyses of existing data. These can generate new insights about potential economic predictors of HIV, but longitudinal research is needed to understand economic impacts on HIV in evolving programme and policy contexts. Limited studies outside the general population highlighted opportunities for future research exploring economic drivers of HIV among the key population and potential differences in the HIV-wealth relationship by gender and urbanicity. CONCLUSIONS: The evidence on HIV and wealth or income is mixed and varies by setting and population, while a limited literature suggests that economic inequality is more consistently associated with HIV risk. Longitudinal research is needed to assess causal relationships between economic factors and HIV, and to identify potential mediators of this relationship.