The current COVID-19 crisis helps bring back at the forefront the concept of One Health which was developed after the emergence in China of another coronavirus, called SARS-CoV-1. This virus was responsible in 2003 of an acute respiratory disease in humans that spread to 26 countries. This pandemic which killed 770 people, seems almost anecdotal compared to the magnitude of the current global crisis. A pandemic like that of COVID-19 we are currently experiencing, caused by SARS-CoV-2, had been anticipated by a large number of scientists and researchers. SARS-CoV-2, like SARS-CoV-1 is believed to be of animal origin. Indeed, the genome of the virus is similar to that of other coronaviruses that are found in particular in certain species of bats and in the pangolin, an insectivorous mammal. It is worth noting that the SARS-CoV-1 pandemic of 2003 was followed few years later in 2009 by another pandemic caused too by a virus of animal origin H1N1 (swine flu). Zoonotic Diseases (Zoonoses) Animals and humans have always shared common environments and constantly exchange many and varied infectious agents, including viruses, bacteria and parasites. Zoonotic diseases or zoonoses are the diseases that are transmitted from animals to humans. It is estimated today that about three-quarters of emerging infectious diseases and more than 60% of all infectious agents that affect human populations are of animal origin. The frequency of emergence of new zoonotic diseases appears to be increasing worldwide and the likelihood of a mutation or a reassortment of a virus that could cause a pandemic of biblical proportion. Why? From animal to human To answer this question, it is necessary to examine the factors that facilitate the adaptation of infectious agents from animals to humans. Some are biological, such as the ability of infectious agents to transform and to adapt to a new host, and others are dependent on changes, largely due to human activity, that affect our planet and our societies and that transform interactions between humans, animals and their environment. Many human activities, including urbanisation, population growth and the intensification of agriculture, are destroying the natural habitats of millions of animal species on the planet at an alarming rate. Climate change is disrupting ecosystems and altering the quality of habitats that become more or less suitable for the survival of these species. Consequently, these animals move, which increases the opportunities for contact with humans who appropriate their territories, promoting the transmission of infectious agents between animals and humans. The COVID-19 pandemic reminds us again that human and animal health are interdependent and linked to the health of the ecosystems in which humans and animals coexist. It is the understanding of this relationship and the interrelatedness of human, animal, and ecosystem health which constitutes the foundation of the One Health Concept. The One Health concept Following the SARS-CoV-1 and the H1N1 pandemics, there was a consensus in the international scientific community that a pandemic disease of the magnitude of the Spanish flu was inevitable but and the only question was when. It is worth noting that the outbreak of SARS in East Asia and Canada led to the economic losses estimated between US$40 and $50 billion. A study done by the World Bank at that time concluded that a severe influenza pandemic could reduce the global GDP by 3 to 5 per cent. Worried about the human and economic cost of a potential pandemic, the World Bank using its convening power, initiated a discussion at international level on how best it could help countries to get prepared to manage the next pandemic. There was a recognition that the current disease management approach focusing on prevention of the emergence and the control of the spread of a disease had shown its limit. A consensus among experts was that we needed to move away from a disease management approach to a system approach of disease management using cross-sectoral and interdisciplinary teams working locally, nationally and globally to attain optimal health for people, animal and our environment. This approach is known as One Health, and has been adopted by physicians, veterinarians, and scientists worldwide, and is promoted by numerous national and international agencies and organisations. The World Bank (WB) than took the lead in the development and the operationalisation of the One Health approach. Multidisciplinary teams of renowned international experts were put together to work on seven themes ranging from training to the development of inter-connected surveillance systems for both animal and human virus. I had the privilege to lead the team comprising of experts from the World Health Organisation (WHO), the UN Food and Agriculture Organisation (FAO), the World Organisation for Animal Health (OIE), the Centre for Diseases control (CDC-Atlanta), the UN Environmental Programme (UNEP) and from the Universities of Michigan State and of Calgary, tasked to develop a One Health self assessment tool. A tool designed to be used by countries in evaluating their performance in the adoption and implementation of the One Health approach by developing related processes, systems and institutions. A lot of work on the One Health proposed approach was done by the World Bank which became the reference organisation in the domain. For readers interested in the subject, I would recommend the book we published titled: “People, Pathogens and Our Planet”. A book in two volumes; with volume 1: “Towards a One Health Approach for controlling zoonotic diseases” we published in 2010 and volume 2: “The Economics of One health” we published in 2012. However, it is worth noting that with the slow disappearance of the urgency of an imminent pandemic disease, the adoption by countries of the One Health approach has widely varied and even faded from the radar screen of many countries caught with more pressing public health priorities. The current Covid-19 pandemic should remind us of the importance for countries to adopt and embrace the One Health concept and develop systems which will allow prevention, early detection and management in case we have another pandemic. By exposing the vulnerabilities in our current health systems, the current Covid-19 should serve as an eye opener for wider and deeper changes in the way we manage diseases and induce a paradigm shift in the way of managing our environment, animal and human health as inter-connected and One Health. Applying this approach will be essential to understanding and then promoting a sustainable balance between the growth of human populations, health, land use and the safeguard of our planet. This is a lesson that must be learned from the COVID-19 crisis if we want to prevent new disasters that could be even worse than the one, we are currently experiencing. The author is a Rwanda-born microbiologist and food safety expert, a former senior official with the federal government of Canada, the World Bank and the UN Food and Agriculture Organisation. He is currently an international consultant/advisor to several multinational bodies including the African Union. The views expressed in this article are of the author.
