[Prevalence of undiagnosed human immunodeficiency virus infection in an emergency department and the characteristics of newly diagnosed patients].

Objectives: To estimate the prevalence of undiagnosed human immunodeficiency virus (HIV) infection detected by routine testing of patients seeking care in an emergency department and to describe the characteristics associated with new HIV-infection diagnosis.

Material And Methods: Walk-in patients between the ages of 15 and 75 years who required a blood test were included. Routine fourth-generation enzyme-linked immunoassays were performed to detect HIV infection in all samples extracted. Patients with positive results were referred to the infectious diseases department for monitoring and treatment.

Results: Blood samples for 1722 patients were analyzed. Twenty-one patients (1.2%) refused to allow their samples to be tested; 19 more samples (1.1%) could not be tested. The prevalence of undiagnosed HIV infection among the remaining 1682 remaining patients was 0.6% (95% CI, 0.23%-0.96%). The prevalence tended to be nonsignificantly higher among patients born outside Spain (0.97% [95% CI, 0.3%-2.20%]) and in 36-50-year-olds (1.46% [95% CI, 0.4%-2.5%]). Characteristics associated with undiagnosed HIV infection were male sex (odds ratio [OR], 5.78 [95% CI, 1.0-31.4]), presenting with a chief complaint that suggested infection (OR, 8.14 [95% CI, 1.6-41.4]), and a history of hepatitis (OR, 5.53 [95% CI, 1.1-27.7]).

Conclusion: The prevalence of undiagnosed HIV infection in our emergency department was high at 0.6%. The rate of patient acceptance of routine HIV testing was high. Strategies that target improving the detection of undiagnosed HIV infection are advisable.