Hepatitis C has surpassed HIV as a cause of death in middle-aged U.S. adults. An analysis of multiple-cause mortality data from 1999 to 2007 shows that, among adults, hepatitis C virus (HCV) infection caused a larger proportion of deaths than hepatitis B virus and HIV infections, and many of those deaths were in middle-aged adults (ages 45 to 64). More than half of the death certificates listing HCV as the cause also reported chronic liver disease as a comorbid condition. Because the incidence of HCV infection has declined, the impending problem of chronic HCV infection in an aging population may be overlooked, and "screening efforts that target middle-aged persons may be profitable," the authors write in the February 21 Annals of Internal Medicine.