Why One Health?
One Health refers to the collaboration of multiple disciplines, sectors and groups working locally, nationally and globally to attain optimal health for people, animals and the environment.1 Recent examples of new and emerging diseases in animals and humans (Ebola, Middle East respiratory syndrome, avian flu (H5N1), swine flu (H1NI), severe acute respiratory syndrome) show how quickly balance changes and how vulnerable humans, animals and crops are to disease outbreaks.2 ,3 Infectious diseases are transmitted between humans and animals by a variety of routes including direct contact (rabies), the environment (anthrax), via food (campylobacter/salmonella/brucella/bovine tuberculosis), or through bites by arthropod vectors (malaria/leishmaniasis/Rift Valley fever). As we have recently seen with the Ebola and Zika outbreaks, in our interconnected world, an animal pathogen can catch a ride on the sole of a shoe, beneath a finger nail, or in respiratory passages, and travel from one remote corner of the globe to another in less than a day. Furthermore, zoonotic illness is not a small or insignificant problem; the majority of human pathogens are zoonotic (60%) and three-quarters of new and emerging pathogens are zoonotic from wildlife species.4 ,5 However, One Health, which is larger than simply zoonosis (other examples include land use, water toxins, forest degradation and climate change (see online supplementary appendix A)), can have a great impact on people and the quality of their lives as well as local and national economies.
Although perhaps the most discussed, infectious diseases are not the only relevant One Health concerns affecting the globe. Waste dumped in or near water flows through streams, rivers and lakes, affecting entire communities—crops, animals and people. Meanwhile, as the human population on the planet increases, humans are forced to live in closer proximity to both wild and domestic animals, which increases exposure to new pathogens, and forces the sharing of limited supplies of water (see online supplementary appendix B). Add to this the growing pressures to increase agricultural production, global warming with the resultant decrease in water supplies, changing microbial patterns, and deforestation, and the result is a deterioration of natural resources and a reduction in many of the protections and checks and balances that have previously been afforded to human populations.
Despite the complex nature of these challenges, most governments have offices or units that focus vertically on specific diseases, and these offices often compete with each other for limited resources. Non-government organisations (NGOs) that align themselves with one issue or disease are often disconnected from interventions for others. It is this sort of Brownian approach to improving health that results in poor communication between disciplines, duplication of services with resulting higher costs, ignoring of common antecedent causes of poor health, and inefficient utilisation of available resources such as specialised reference laboratory facilities. Academic communities, local and national governments, and scientists worldwide are now recognising that the next logical step in problem solving is to connect interdisciplinary and government agency experts so that they can focus on the root causes of illness and the need for prevention and detection rather than responding separately and acutely to each disease. The activities and conditions of each individual, each region, and each country affect others on a variety of levels including economic, cultural, physical, social and more. While very few sub-Saharan African countries are taking steps to put these ideas into action, Rwanda is unique in that it is well on its way.