Risk of hepatitis C transmission from infected medical staff to patients: model-based calculations for surgical settings.

CONTEXT Concern is increasing in both the medical community and among the general public about the possible transmission of hepatitis C virus (HCV) from infected health care workers to their patients. Until now, no reliable estimates for the risk of such transmission exist. OBJECTIVE To estimate the probability of HCV transmission from a surgeon to a susceptible patient during invasive procedures. DESIGN A model consisting of 4 probabilities was used: (A) the probability that the surgeon is infected with HCV, (B) the probability that the surgeon might contract percutaneous injuries, (C) the probability that an HCV-contaminated instrument will recontact the wound, and (D) the probability of HCV transmission after exposure. Values for the calculations were taken from published studies. RESULTS When the surgeon's HCV status is unknown, the risk of HCV transmission during a single operation is 0.00018% +/- 0.00002% (mean +/- SD). If the surgeon is HCV RNA positive, this risk equals 0.014% +/- 0.002%. The likelihoods of transmission in at least 1 of 5000 invasive procedures performed by a surgeon during 10 years are 0.9% +/- 0.1% (HCV status unknown) and 50.3% +/- 4.8% (HCV RNA positive), respectively. CONCLUSIONS The calculated risks for HCV transmission from a surgeon to a susceptible patient during a single invasive procedure are comparable to the chance of acquiring HCV by receiving a blood transfusion. These figures could provide a basis for further discussions on this controversial subject and might also be relevant for future recommendations on the management of HCV-infected health care workers.