In a globalising world, we see with an increasing demand for meat and animal products an unprecedented transport of these products within and between countries. Unfortunately, the transport of animal meat and fodder entails also the transport of animal- and human diseases. Major epidemic livestock diseases, including e.g. bovine plague, bovine spongiform encephalopathy, foot-and-mouth disease, contagious caprine pleuropneumonia, and rift valley fever, often migrate or spread across borders with the transport of ‘animal proteins’, cause major losses and emergencies, and can pose threats to human health. In the past, such damage has on occasions been catastrophic, leading to famines and sometimes triggering trade restrictions. These transboundary diseases are among the most contagious and place a serious burden on the economies of the countries in which they occur.
The reasons for this increasing risk are complex, but the main contributing factors have been identified as follows :
- alteration of the environment affecting the size and distribution of certain animal species, vectors, and transmitters of infectious agents of humans;
- increasing human populations favouring an increased level of contact between humans and infected/affected animals
- industrialization of foods of animal origin; changes in food processing and consumer nutritional habits; and,
- increasing movements of people as well as trade of animals and animal products and decreasing activities for the surveillance and control of major zoonoses.
As the trade of animal products and the movements of people become more intense, the risks of introduction/reintroduction of certain diseases in a country increase. It is very likely, in view of the foreseeable global changes over the next few decades (e.g., population growth, urbanization, and climatic changes), that this trend will continue and even increase. Human disease patterns will be affected by high densities and movements of human populations within and between countries and changes in lifestyles; animal disease patterns will be affected by changing land-use patterns, new farming practices, displacement of animals, and environmental contamination.
Until now, as described above, the number of fatalities has remained relatively low. However, the question seems to be shifting from ‘Will there be a pandemic’ to ‘When will it occur?’. An even more pertinent question is what a future pandemic will entail. Will the number of victims be limited or will it be an extremely contagious, lethal disease, so grave that it may be deemed a ‘hyperdisease’?
The ‘hyperdisease hypothesis’ was developed by Ross MacPhee and Preston Marx. They assert that extremely contagious and fatal infectious diseases were decisive elements to the extinction of various animal species in regions such as North America. These hyperdiseases are not completely new diseases, but diseases that have ‘jumped’ from one spe-cies to another. Examples from the past underline that (viral) infectious diseases regularly jump from animals to humans. Increasing contact between people and (domesticated) animals, and increasing contacts between people among themselves (due to factors such as growing populations and increased mobility) command us to take these kinds of extreme scenarios seriously.