Challenges posed by new and re-emerging infectious diseases in livestock production, wildlife and humans

In today's world, emerging and re-emerging diseases have a significant impact on global economies and public health, and with bioterrorism a constant threat this has become a very topical subject in recent years. Bernard Vallat, director general of the OIE, made the statement, “As a result of globalisation and climate change we are currently facing an unprecedented worldwide impact of emerging and re-emerging animal diseases and zoonoses”. He is not alone in this thinking, but are we facing an unprecedented impact of diseases and are globalisation and climate change the main driving forces? This paper examines some historical disease outbreaks and the factors that played a role in their emergence and compares these with recent emerging diseases. In doing so it highlights certain challenges that face livestock producers and decision makers today as they grapple with emerging diseases. One of the driving forces for the emergence of diseases is translocation of people and their livestock and this has often been coupled with invading armies or peoples, political unrest and a concurrent environment of socio-economic upheaval. Contact between wild animals, domestic animals and people is another driving force involving the interaction between naïve population groups that induces the emergence of new diseases. Pandemics are not new to human society and nor are many of the driving forces that caused them to occur in the past; what has changed is our increased knowledge and awareness of disease dynamics, allowing identification of challenges for the future and ways of addressing these. Modern farming practices often serve to amplify emerging infectious diseases and modern trade and transport mechanisms and routes have served to sometimes accelerate the spread of disease. How can we reduce the risks and should we only be worried about emerging infectious diseases or are emerging non-communicable diseases just as important in our modern society? This paper serves to explain some of the reasons for the emergence of diseases and to try and answer some of the pressing questions that confront livestock producers today