Prevalence and Characteristics of Patients with Undiagnosed HIV Infection in an Urban Emergency Department

Abstract

The Centers for Disease Control and Prevention (CDC) recommends offering HIV testing to persons admitted to emergency departments (EDs). Whether by opt-in or opt-out, many EDs (including our own) have found a seroprevalence of 0.8-1.5% when rapid testing is offered. The true seropositivity rate is unknown. We performed a retrospective chart analysis upon all patients presenting to our ED over a 2-week period in the fall of 2007 who had serum drawn as a part of their emergency care. Demographics and clinical characteristics were linked via de-identified serum, which was sent for HIV testing. Nine hundred fifty nine patients had sera available for rapid HIV testing. One hundred twenty one (13%) samples were reactive via the OraQuick(®) test (OraSure Technologies, Bethlehem, PA), a point of care rapid antibody test. Due to concerns about the appropriateness of sera as substrate for the OraQuick(®) technology, reactive samples were retested via standard enzyme immunoassay (EIA)/Western blot. One hundred twelve analyzable samples were retested-38 were positive and 27 of these were from patients who reported a history of HIV infection. The rate of undiagnosed HIV infection was 1.2% (11/914 potentially analyzable samples). Of all patients with HIV in our ED, 29% of them were presumably unaware of their diagnosis. In conclusion, HIV seroprevalence in our urban ED is high, and a large fraction of the patients appears to be unaware of the infection.