Screening for hepatitis C virus infection: A review of the evidence for the US Preventive Services Task Force

Background: Hepatitis C virus (HCV) is the most common bloodborne pathogen in the United States and is an important cause of patient morbidity and mortality, but it is unclear whether screening to identify asymptomatic infected persons is appropriate. Purpose: To synthesize the evidence on risks and benefits of screening for HCV infection. Data Sources: MEDLINE (through February 2003), Cochrane Clinical Trials Registry (2002, Issue 2), reference lists, and experts. Study Selection: Controlled studies of screening and antiviral therapy and observational studies on other interventions, risk factors, accuracy of antibody testing, work-up, harms of biopsy, and long-term outcomes. Data Extraction: Using preset criteria, the authors assessed the quality of included studies and abstracted information about settings, patients, interventions, and outcomes. Data Synthesis: There are no published trials of screening for HCV infection. Approximately 2% of U.S. adults have HCV anti-bodies, with the majority having chronic infection. Risk factor assessment could identify adults at substantially higher risk. Antiviral treatment can result in a sustained virologic response rate of 54% to 56%, but no trials have been done specifically in asymptomatic patients likely to be identified by screening. Data are insufficient to determine whether treatment improves long-term outcomes. There are no data to estimate the benefit from counseling or immunizations. Although risks of biopsy and treatment appear minimal or self-limited, data on other adverse effects of screening, such as labeling or anxiety, are sparse. Conclusions: Antiviral treatment can successfully eradicate HCV, but data on long-term outcomes in populations likely to be identified by screening are lacking. Although the yield from targeted screening, particularly in intravenous drug users, would be substantially higher than in the general population, data are inadequate to accurately weigh the overall benefits and risks of screening in otherwise healthy asymptomatic adults.