Diseases produced by spirochetes, including Lyme borreliosis, syphilis and leptospirosis, are on the rise worldwide, and because the biology of their causative organisms, their epidemiology, and clinical presentation display important variations in different geographical areas. For example B. burgdorferi sensu lato produces approximately 20,000 cases of Lyme borreliosis a year in the United States and 60,000 cases in Europe, but B. burgdorferi sensu stricto, B. afzelii and B. garinii are transmitted by different vectors and have different reservoirs and clinical presentations in these different geographic areas. Awareness and better understanding of these variations by researchers in the field is thus highly relevant to improvements in their prevention and treatment, and critical for improvement of human health. This volume focuses on a series of state-of-the-art presentations of the research taking place in the laboratories of the contributors. As such, it may be useful as an introduction to those individuals entering in the burgeoning field of spirochete research. This book could serve as a stimulus for researchers in the field to widen collaborations and exchanges between investigators in the different geographical areas where spirochetal diseases are common since these interactions can only be of benefit to the field.