One Health is an emerging concept that aims to bring together human, animal, and environmental health. Achieving harmonized approaches for disease detection and prevention is difficult because traditional boundaries of medical and veterinary practice must be crossed. In the 19th and early 20th centuries this was not the case-then researchers like Louis Pasteur and Robert Koch and physicians like William Osler and Rudolph Virchow crossed the boundaries between animal and human health. More recently Calvin Schwabe revised the concept of One Medicine. This was critical for the advancement of the field of epidemiology, especially as applied to zoonotic diseases. The future of One Health is at a crossroads with a need to more clearly define its boundaries and demonstrate its benefits. Interestingly the greatest acceptance of One Health is seen in the developing world where it is having significant impacts on control of infectious diseases.

<p><b>Introduction.-</b> One Health: its origins and its future

<b>The concept of One Health.-</b> One Health and emerging infectious diseases: clinical perspectives
The historical, present, and future role of veterinarians in One Health
The importance of understanding the human-animal interface
the human environment interface: Applying ecosystem concepts to health
Wildlife: the need to better understand the linkages
The economic value of One Health in relation to the mitigation of zoonotic disease risks. - <b>Examples of a One Health approach to specific diseases from the field</b>
The application of One Health approaches to henipavirus research. - H5N1 highly pathogenic avian influenza in Indonesia: Retrospective considerations
Rabies in Asia: the classical zoonosis
Japanese encephalitis: On the One Health agenda
Cost estimate of bovine tuberculosis to Ethiopia
The pandemic H1N1 influenza experience
One Health: The Hong Kong experience with avian influenza.-<i>Clostridium difficile</i> infection in humans and piglets: a 'One Health' opportunity
Cysticercosis and Echinococcosis
Men, primates and germs: an ongoing affair
Subject index.</p>