Pestiviruses: old enemies and new challenges.

The genesis for this special issue on pestiviruses was a joint meeting on pestiviruses organized by the US BVDV Symposia Committee and the European Society for Veterinary Virology that was held October 14 and 15, 2014 in Kansas City, MO. The theme of the meeting was "Pestiviruses: Old enemies and new challenges". The impetus for this joint effort was the recognition that regional approaches to disease control are at odds with the worldwide traffic in animal products and biologics. Further, the control of newly recognized pestiviruses, such as HoBi-like viruses, is more effective when approached as a global challenge rather than any one nation's problem. The joint meeting featured talks by researchers from North America, South America, Australia and Europe. The papers in this issue arose from keynote talks presented at the joint meeting and are organized around the following themes; pestiviruses and the immune system, genetic variability, the emergence of new pestiviruses and pestivirus control programs.