Traditional influenza surveillance is often referred to as one of the best developed global surveillance systems. Nevertheless, there are huge gaps in many countries, particularly at the dangerous interface between humans, animals and birds. Effective surveillance helps policy makers prepare for upcoming influenza seasons, develop suitable strains for vaccine production and prepare for the possibility of a pandemic outbreak. In the seven chapters of this book, international epidemiologists, virologists, pandemic resilience managers and clinicians convene to share their expert analysis and commentary on influenza surveillance. The book will be of great interest to epidemiologists, clinicians, respiratory medicine specialists, virologists and medical and biomedical students seeking to gain a greater understanding of the surveillance of an ever-present biological threat.