Hepatitis C virus (HCV) infection is highly prevalent in patients seeking care in urban emergency rooms, according to two separate studies that each demonstrate a prevalence of approximately 14 percent. In both studies published in the May issue of Clinical Infectious Diseases, roughly onethird of positive cases were previously undiagnosed and more than a quarter of these HCV-positive cases would have remained undiagnosed using current screening strategies, causing the authors to call for expanding birth cohort-based screening criteria. Current screening strategies for HCV detection rely on the U.S. Centers for Disease Control and Prevention (CDC) birth cohort screening recommendations— one-time HCV testing in those born from 1945 to 1965—in combination with targeted risk-based testing. Given that emergency departments serve as a safety net for underserved patients that may be at high risk for HCV because of HIV status and/or intravenous drug use (IDU), and that emergency departments have shown some success as an HIV screening venue, they may be a strategic partner for expanding national HCV screening. “While we cannot know with certainty the extent to which our findings are generalizable to other emergency departments, we suggest that undiagnosed HCV is likely to be endemic in the emergency department populations […]