The European public health and blood authorities responded to the threat posed by West Nile virus to blood safety of blood and blood components by adopting preventive measures which are defined in the EU blood legislation, professional guides of the Council of Europe and the EU WNV blood transfusion preparedness plan. The measures include the deferral of blood donors that have visited or residing in a NUTS 3 area considered to be affected (i.e. with at least one confirmed case).