Medical health professionals are at risk of becoming infected with hepatitis C virus (HCV) after occupational exposure. 1 The risk of transmission ranges from 0% to approximately 10%. 2, 3 To our knowledge, at this time, there is no effective method to prevent HCV infection in a person who has a needlestick accident, and follow-up strategies after a needlestick injury are not well-defined. Determination of transaminase levels and the presence or absence of HCV RNA is usually done at least for 6 months. However, it is unclear whether these recommendations are sufficient to prevent unrecognized HCV infection.

From January 1997 through October 2007, 12 patients with HCV due to documented transmission (11 patients with HCV due to needlestick injury and 1 patient with HCV due to scalpel injury) were seen at our outpatient department. Following patient exposure, we tested serum transaminase, antibodies to HCV, and HCV RNA by a polymerase chain reaction assay (ABI Prism 7700 and/or ABI Prism 7500 Fast; Applied Biosystems), with a lower detection limit of 50 IU/mL. Patients were tested within 24 hours and 1, 2, 3, 6, 9, and 12 months after the accident. For 1 patient who had an unusually long incubation period, the CD4+ T cell response was assessed using a 3H-thymidine incorporation assay. A proliferation assay and the stimulation