Deja Tu Huella: a comprehensive review of a successful emergency department-based, HIV-targeted screening program in Spain and its impact on early diagnosis and public health.

Failure to diagnose human immunodeficiency virus (HIV) and late HIV diagnosis persist across Europe and Spain, sustained by missed diagnostic opportunities in routine care. Emergency departments (EDs), often the sole point of contact for vulnerable groups, are pivotal yet underused venues for early case finding. In response, the Spanish Society of Emergency Medicine (SEMES), with scientific sponsorship of the AIDS Study Group (GESIDA), published a consensus document recommending a targeted, opt-in HIV testing strategy in EDs triggered by specific HIV indicator conditions. This first consensus also emphasized standardized communication of results and linkage pathways to infectious disease care, and the use of electronic decision-support systems (preconfigured analytical panels and pop-up alerts) to normalize test ordering within ED workflows. An updated consensus later added further indicator conditions and recommended bundling hepatitis C virus (HCV) serology with every HIV test, supported by electronic health record (EHR)-based decision-support tools, clear linkage-to-care pathways and expanding the role of nursing. Deja Tu Huella translates these recommendations into routine ED practice at scale. Launched in 2021, the program combines multi-stakeholder governance, standardized clinical pathways, EHR-integrated order sets and alerts, and structured training for ED teams. By 2025, 187 hospital EDs adopted the program, requesting 223,659 HIV serologies and identifying 2,357 new cases (mean positivity: 1.15%). Participating EDs account accounted for >20% of national diagnoses, with rapid linkage to antiretroviral therapy (median: 4-9 days). The program has also generated a substantial body of peer-reviewed research that has iteratively informed updated SEMES recommendations. The initiative was co-developed by SEMES in collaboration with Gilead Sciences, which supported education, data generation, and deployment of EHR-based decision-support tools. Overall, Deja Tu Huella demonstrates that an indicator condition-based, opt-in HIV testing strategy, embedded in ED workflows and supported by decision-support tools and education, can achieve high diagnostic yield and timely linkage to care. This experience offers a scalable template for ED-based HIV and HCV screening that may be adaptable to other health systems seeking to accelerate progress toward the UNAIDS 95-95-95 targets.