Re-evaluation of chronic hepatitis B and hepatitis C patients lost to follow-up: results of the Northern Holland hepatitis retrieval project.

Background: Many persons infected with Hepatitis B virus (HBV) and Hepatitis C virus (HCV) in the past are now lost to follow-up. The aim of the Northern Holland Hepatitis Retrieval Project (NHHRP) is to retrieve and re-evaluate persons previously diagnosed with HBV or HCV and bring them back into care. Chronic HBV infection was defined as two positive Hepatitis B surface antigen (HBsAg) tests within 6 months and chronic HCV infection with 2 positive HCV RNA tests by polymerase chain reaction (PCR).