A survey of U.S. households conducted between 2003 and 2010 revealed that approximately 2.7 million US residents are infected with chronic hepatitis C virus (HCV). This figure marks a decrease by about 500,000 cases identified by a similar analysis conducted between 1999 and 2000. The findings are being published in Annals of Internal Medicine.

Chronic HCV infection is an important public health issue because those who are infected are at high risk for liver disease and other chronic illnesses. Treatment can cure the disease and decrease risk for death, yet many persons infected with HCV do not know they have it. Currently, more people in the U.S. die from HCV than from HIV infection.

Knowledge of the number of persons with HCV infection is critical for public health and policy planning. Investigators conducted a nationally representative household survey to estimate the prevalence of HCV and to identify risk factors for infection. They found that the estimated prevalence of chronic HCV infection in the U.S. is about 2.7 million, a decrease of about 500,000 cases since the previous survey. This decrease could be attributed from deaths due to the disease.

Risk factors are essentially unchanged from previous periods (injection drug use, having a blood transfusion before 1992). Because only about one half of infected persons report having at least one of these risk factors, risk-based screening may not be the best way to identify chronically ill persons.

Baby boomers are six times more likely than other adults to be infected, so the Centers for Disease Control and Prevention recommend a one-time screening for all persons born between 1945 and 1965. The authors write that information from this survey will help to inform the design of programs for HCV screening and linking patients to care and treatment.