A study by the Centers for Disease Control and Prevention suggests that 4.1 million individuals in the United States have been infected with hepatitis C virus (HCV), and most have chronic infections (Armstrong GL et al. Ann Intern Med. 2006;144:705-714). More than 15 000 participants in the National Health and Nutrition Examination Survey conducted between 1999 and 2002 provided medical histories and were tested for antibodies to HCV, the presence of HCV RNA, and serum alanine aminotransferase levels (a measure of liver function).
Hampton T. Hepatitis C Prevalence. JAMA. 2006;295(24):2839. doi:10.1001/jama.295.24.2839-a