New Diagnoses of Human Immunodeficiency Virus Infection in a Hospital Emergency Department: Clinical Characteristics and Factors Associated with Late Diagnosis.

BACKGROUND

Emergency departments (EDs) play an important role in identifying previously undiagnosed human immunodeficiency virus (HIV) infection. However, late diagnosis remains common and is associated with increased morbidity, mortality, and ongoing transmission.

OBJECTIVES

To describe new HIV diagnoses in an ED, estimate late diagnosis frequency, and identify associated factors.

METHODS

This single-center observational retrospective study included 99 patients with a new HIV diagnosis confirmed by serology testing requested in the ED of the Hospital Universitario 12 de Octubre, Madrid (Spain), between January 2022 and August 2025. Late diagnosis was defined as CD4 < 350 cells/µL and advanced disease as CD4 < 200 cells/µL. Factors associated with late diagnosis were analyzed using logistic regression.

RESULTS

Ninety-nine new infections were confirmed from 10,609 HIV serologies (positivity 0.93%). Median CD4 count at diagnosis was 216 cells/µL (interquartile range: 83-390). Overall, 64.4% met criteria for late diagnosis and 47.1% for advanced disease. Older age was associated with higher odds of late diagnosis (odds ratio [OR] 1.10; 95% confidence interval [CI]: 1.02-1.19; p = 0.009), whereas testing in the context of suspected sexually transmitted infection (STI) was associated with lower odds (OR 0.32; 95% CI: 0.11-0.94; p = 0.039). Median time from ED visit to first HIV clinic appointment and to antiretroviral therapy (ART) initiation was 6 and 10 days, respectively.

CONCLUSION

New HIV diagnoses made in the ED frequently occurred at advanced stages; however, linkage to care and ART initiation were promptly implemented. Systematic HIV screening, especially beyond STI-related presentations, is essential to reduce late diagnosis in this setting.