One world, one health

The notion that humans, animals and the environment are tightly linked and that their respective well-beings are interdependent has been recognized for centuries. However, the sophistication of these interactions has only begun to be revealed. Even by the late nineteenth century, it was established knowledge that human and animal health have many commonalities; an insight that more recently led to the term ‘One Medicine’, coined in 1984 to integrate human and veterinary health and research. In 2003, after the severe acute respiratory syndrome (SARS) epidemic, One Medicine evolved into the concept of ‘One Health’, which expands the idea beyond a focus on the health of animals and humans to include health service delivery, environmental health and ecosystem services (for further reading, see Sidebar A). It defines ‘health’ as a broader concept, whereby humans, animals and the environment are inextricably linked and where each need equal attention to ensure optimal health for all. Although it is an interesting and forward-looking concept, One Health has unfortunately not gained significant attention, particularly in the area of human health.