25/08/2014 08:29 BST | Updated 22/10/2014 06:59 BST

Acknowledging the Underlying Cause of Epidemics

The recent Ebola outbreak has now claimed more than a thousand lives in four countries. Scientists are scrambling to find a viable pharmaceutical cure, while medical personnel and government officials try to cope with the strain put on existing health-care systems. Ethical dilemmas have arisen over who should receive potentially life-saving drugs and when. These are certainly important issues for a global conversation. However, an important ethical issue which has thus far been under-discussed is the role of the consumption of animal flesh in the origin and spread of epidemics.

While some attention has been given to the African practice of hunting and eating fruit bats, a likely animal reservoir of the Ebola virus, the link between eating meat and the plethora of infectious disease outbreaks is seldom articulated. Bush meat in general carries a high risk of disease - for example, flesh from hunted chimpanzees is the probable source of the HIV/AIDS epidemic, which has now claimed the lives of more than 36 million people. But the risk does not end with bush meat - it is indisputable that live animal markets in China were the catalyst for SARS, H5N1 and numerous other viral outbreaks over the past decade. Fuel for the influenza epidemics is provided by the high density of birds and pigs in eastern China, providing a mixing bowl for genetic variants capable of infecting humans. But we don't have to look far from our own backyards to find examples of that, too: the H1N1 influenza epidemic of 2009, in which up to half a million people died worldwide, traces its probable origin and early spread to North American pig farms. Pigs are also a likely source of methicillin-resistant Staphylococcus aureus. So are cows, who also carry disease-causing E. coli bacteria, which cost the US government more than $250 million annually. That's small change, though, compared to the $1.3 billion spent by the US government on Campylobacter jejuni bacterial infections originating in chickens.

And consider that these are just the infectious agents that have made the successful jump to humans. Many more pathogens circulate in animals intended for food that cause billions in economic loss for farmers and represent a simmering underlying threat to human health, including mad cow disease, foot and mouth disease virus, the pool of influenza variants around the world and probably a vast number of other dangerous diseases that remain unknown - for now.

The case against meat consumption grows stronger every day, with new research showing its detrimental effects on our long-term health, the environment and the usefulness of our antibiotics supply. To this list, we must be willing to add that eating meat - whether bush meat from jungles, the corpses of birds bought at markets, ground pork purchased off the shelves of the local mega-store or any other kind - is directly responsible for major outbreaks of infectious diseases. So far, we've been lucky in preventing a truly global pandemic - but not the loss of millions of human lives and expenditures of billions of dollars. We know that animals are the source of the majority of new and re-emerging diseases in humans. Surely it's time for us to acknowledge this and to determine what we need to do about it before we are overwhelmed by an outbreak that we truly cannot control.