HIV seroprevalence, treatment cascade outcomes, and determinants of seropositivity in East Africa: a multi-country analysis of population-based HIV impact assessment surveys

HIV remains a major public health challenge in East Africa despite progress in antiretroviral therapy (ART). Although Population-based HIV Impact Assessment (PHIA) surveys provide high-quality, standardized data, multi-country comparisons of HIV seroprevalence, treatment cascade outcomes, and associated factors remain limited. A secondary analysis of five PHIA surveys conducted between 2017 and 2023 in Ethiopia (urban only), Kenya, Rwanda, Tanzania, and Uganda was performed. Specifically, descriptive analyses estimated HIV seroprevalence, awareness of HIV status, ART coverage, and viral load suppression. In addition, country-stratified, survey-weighted multivariable logistic regression was used to identify correlates of HIV seropositivity among 132,954 consenting adults aged 15–64 years. Variables were screened at p ≤ 0.20 for inclusion in multivariable models; thereafter, complete-case analysis was used for regression. HIV seroprevalence ranged from 3.0% in urban Ethiopia and Rwanda to 5.9% in Uganda. Moreover, recent infections accounted for 0.5%–2.0% of HIV-positive cases. Prevalence among women was roughly double that among men, peaking among adults aged 45–64 years in Kenya, Rwanda, Tanzania, and Uganda, whereas in urban Ethiopia, it peaked among those aged 35–44 years. Additionally, prevalence was lowest among participants with secondary or higher education. Status awareness ranged from 79.0% (urban Ethiopia) to 83.8% (Rwanda). Moreover, among participants aware of their HIV-positive status, ART coverage was consistently high (96.0%–97.7%). Nevertheless, viral load suppression ranged from 87.6% (urban Ethiopia) to 94.1% (Tanzania). Factors independently associated with HIV seropositivity included female sex (AOR ranging from 1.4 in Rwanda to 3.4 in Kenya), previously married status (AOR = 2.3 in Ethiopia to 3.5 in Uganda), prior tuberculosis diagnosis (AOR = 1.9 in Rwanda to 8.0 in Ethiopia), and urban residence (AOR = 2.1 in Rwanda). Across the study settings, HIV status awareness remains the principal barrier to regional epidemic control. Although substantial progress has been made in ART coverage and viral load suppression, undiagnosed infection remains the major programmatic gap. Furthermore, HIV seropositivity is strongly associated with sociodemographic factors and clinical history. Therefore, accelerating progress toward the UNAIDS 95–95–95 targets requires expanding differentiated services, strengthening HIV-TB service integration, and sustaining evidence-based prevention strategies to overcome these persistent disparities.