Undiagnosed HIV and HCV Infection in a New York City Emergency Department, 2015.

OBJECTIVES:To measure undiagnosed HIV and HCV in a New York City emergency department (ED). METHODS:We conducted a blinded cross-sectional serosurvey with remnant serum from specimens originally drawn for clinical indications in the ED. Serum was deduplicated and matched to (1) the hospital's electronic medical record and (2) the New York City HIV and HCV surveillance registries for evidence of previous diagnosis before being deidentified and tested for HIV and HCV. RESULTS:The overall prevalence of HIV was 5.0% (250/4990; 95% confidence interval [CI] = 4.4%, 5.7%); the prevalence of undiagnosed HIV was 0.2% (12/4990; 95% CI = 0.1%, 0.4%); and the proportion of undiagnosed HIV was 4.8% (12/250; 95% CI = 2.5%, 8.2%). The overall prevalence of HCV (HCV RNA ≥ 15 international units per milliliter) was 3.9% (196/4989; 95% CI = 2.8%, 5.1%); the prevalence of undiagnosed HCV was 0.8% (38/4989; 95% CI = 0.3%, 1.3%); and the proportion of undiagnosed HCV was 19.2% (38/196; 95% CI = 11.4%, 27.0%). CONCLUSIONS:Undiagnosed HCV was more prevalent than undiagnosed HIV in this population, suggesting that aggressive testing initiatives similar to those directed toward HIV should be mounted to improve HCV diagnosis.