Advanced HIV Disease at First Diagnosis in South Brazil Extended Beyond Traditionally Targeted Populations: A 10-Year Hospital-Based Study (2015-2024).

Background: Advanced HIV disease (AHD) remains a major contributor to HIV-related morbidity and mortality. While HIV screening strategies in Brazil emphasize populations traditionally considered at high risk, a significant number of individuals without previous HIV infection present with AHD despite lacking recognized risk profiles. This study aimed to define the sociodemographic and behavioral characteristics of patients presenting with advanced HIV at diagnosis, with the goal of identifying gaps in current HIV screening efforts. Methods: We conducted a retrospective cohort study of patients hospitalized in the infectious diseases ward of a tertiary referral hospital between January 2015 and December 2024. We included individuals previously unaware of their HIV status who met World Health Organization (WHO) criteria for AHD, defined as CD4 count < 200 cells/mm Results: Among 1615 unique patients hospitalized with AHD, 407 (25%) were newly diagnosed with HIV during hospitalization. The median CD4 count at diagnosis was 53 cells/mm Conclusions: AHD at first diagnosis was not concentrated within traditionally recognized high-risk populations. The diversity of patients presenting with AHD at first diagnosis suggests that reliance solely on traditional risk-based screening strategies may be insufficient to ensure timely detection. Expanded routine, opt-out HIV testing across healthcare settings, as well as indicator-based testing, self-testing, and pharmacy-based testing may help reduce missed opportunities for diagnosis and prevent severe immunosuppression.