Transmission of hepatitis C virus during myocardial perfusion imaging in an outpatient clinic.

Reports of health care--associated viral hepatitis transmission have been increasing in the United States. Transmission due to poor infection control practices during myocardial perfusion imaging (MPI) has not previously been reported. The aim of this study was to identify the source of incident hepatitis C virus (HCV) infection in a patient without identified risk factors who had undergone MPI 6 weeks before diagnosis. Practices at the cardiology clinic and nuclear pharmacy were evaluated, and HCV testing was performed in patients with shared potential exposures. Clinical and epidemiologic information was obtained for patients with HCV infection, and molecular testing was performed to assess viral relatedness. Evidence of HCV transmission among patients who had undergone MPI at the cardiology clinic on 2 separate dates was found, involving 2 potential source patients and a total of 5 newly infected patients. Molecular testing identified a high degree of genetic homology among viruses from patients with common procedure dates. The nuclear medicine technologist routinely drew up flush from multidose vials of saline solution using the same needle and syringe that had been used to administer radiopharmaceutical doses. Multipatient use of vials was not observed, but a review of purchasing invoices and interviews with staff members suggested that this had occurred. No evidence of transmission via contamination of radiopharmaceuticals at the nuclear pharmacy was found. In conclusion, transmission of HCV occurred because of unsafe injection practices during MPI. Cardiologists should carefully review their infection control practices and the practices of other staff members involved with these procedures.