A German scholar from the mid 1800's, Rudolf Virchow, who came from a farming family, was an early proponent of the concept of One Health. He said, "Between animal and human medicine there is no dividing line-nor should there be. The object is different but the experience obtained constitutes the basis of all medicine."
During the last 3 decades, approximately 75 percent of emerging infectious diseases among humans have been zoonotic meaning diseases that can be transmitted from animals to people. This has encouraged modern proponents of OH. In the 1980's, epidemiologist Calvin Schwabe called for a unified human and veterinary approach to combat zoonotic diseases, providing the modern foundation for OH.
The concept was advanced further when, in 2004, the Wildlife Conservation Society hosted a symposium that brought together an international group of human and animal health experts to discuss shared diseases among human, wild animal, and domestic animal populations. This symposium introduced a set of priorities for an international and interdisciplinary approach to combat joint threats to human and animal health. In 2007, The American Veterinary Medical Association and the American Medical Association, adopted a vision supporting the concept of OH and formed the One Health Initiative task force. The task force brought together U.S. human and animal health agencies, medical doctors, and veterinarians. In addition, the National Strategy for Pandemic Influenza and its Implementation Plan resulted in several International Ministerial Conferences culminating in 2007 that involved the United Nations' Food and Agriculture Organization (FAO), the World Organization for Animal Health (OIE), and the World Health Organization. OH has also gained ground throughout the U.S. Government, led by the President's new initiatives for coordination and collaboration on national security and global development policy.