Trends in residual risk of transfusion-transmitted viral infections in France between 1992 and 2000

BACKGROUND: Monitoring trends in residual risks of transfusion-transmitted viral infections (HIV, HTLV, HBV, and HCV) is important to assess improvements in blood safety. In France, theses trends were analyzed between 1992 and 2000. STUDY DESIGN AND METHODS: As risk is predominantly associated with the window period, residual risks were estimated by multiplying incidence rates by the durations of the window periods. Incidence rates were calculated from the data collected by the blood transfusion centers belonging to the Transfusion-Transmissible Agents Working Group, which currently collects more than 50 percent of the 2.5 million blood samples donated each year in France. RESULTS: Trend analysis showed a significant decrease in residual risks for HCV (p = 0.01) and HBV (p < 0.001). Although residual risks decreased for HIV and HTLV, the trends were not significant. In 1998 through 2000, residual risks were estimated to be 1 in 470,000 donations for HBV, 1 in 860,000 for HCV, 1 in 1,370,000 for HIV, nil for HTLV, and 1 in 250,000 for the four viruses combined. CONCLUSIONS: In France, the current risk of a blood recipient becoming infected with a retrovirus or a hepatitis virus is extremely low. The implementation of NAT in July 2001 is predicted to reduce the residual risk to 1 in 2,700,000 donations for HIV and 1 in 8,300,000 for HCV.