Systems to monitor the safety of the blood supply were used initially to describe and monitor transmissible disease rates and to estimate the residual risk of infection. As new assays were implemented, surveillance data became important to measure the impact of new testing and to revise risk estimates. With improvements in testing, the benefit of additional testing and of some donor selection criteria was less clear. Transmissible disease surveillance has developed in different directions in different countries. Speakers will describe surveillance in their own country and their perspective on applications as well as future directions.