Delia Grace, a veterinary epidemiologist with the International Livestock Research Institute (ILRI), works in Africa and South and Southeast Asia on livestock food safety and disease issues (picture credit: ILRI/Mann).
With more than 6 billion people and over 20 billion livestock, the world is getting crowded—with risks increasing of livestock diseases causing devastating human as well as animal plagues.
BBC Radio 4 presenter Charlotte Smith interviewed Delia Grace for the ‘Farming Today’ program on this topic yesterday (7 March 2011).
BBC: ‘The risk of a global flu epidemic is increasing because developing countries are keeping more livestock, according to a new report. The International Livestock Research Institute [ILRI] believes that with more animals being farmed in Asia and Africa as populations grow and diets change, there’s a greater chance of diseases, from SARS to avian flu, transferring between animals and from animals to humans. Delia Grace is based in Nairobi; she’s the co-author of the report. She told [us] why keeping more animals brings more risk.’
Grace: ‘Most human diseases, in fact nearly two-thirds of human diseases, are actually shared with livestock. They’re what we call “zoonoses”—that means diseases transmissible between animals and people. So if you get more animal diseases, then you’re likely to get more human diseases.’
BBC: ‘WHY IS THERE A GREATER LIKELIHOOD OF THAT NOW, THEN?’
Grace: ‘What we’re seeing now in developing countries is more people and more animals than have ever been seen before at any time in history. These numbers are actually unprecedentally large. We have round about 6 billion people and over 20 billion animals. There are more contacts between humans and animals simply because there are more humans and animals. And also in developing countries people live very close to their animals and they keep animals in ways that are not seen so much in the richer more developed countries. And all this—numbers and ways of interacting with animals—brings new opportunities for diseases to spread, both among animals and between animals and people—and then between people.
BBC: ‘WHAT ABOUT ENVIRONMENTAL REGULATION TO PREVENT DISEASES FROM SPREADING. IS THAT NOT AN OPTION, NOT AN ISSUE, HERE?’
Grace: ‘It’s a very good idea of it can be made to work. What we tend to find is that regulations are well funded and well applied in richer countries, but in the poorest countries, regulations often don’t make it from policy into practice.’
BBC: ‘COULD YOU EXPLAIN WHY LIVESTOCK NUMBERS ARE INCREASING SO QUICKLY?’
Grace: ‘It’s really a demand-driven increase in livestock numbers. What we’re seeing is that as populations get richer and bigger, their demand for animal-source food increases and increases more quickly than their demand for staple foods such as rice and maize. This demand is obviously driving an increase in supply.’
BBC: ‘IF AN EPIDEMIC DID TAKE HOLD, WHAT IMPACT WOULD THAT HAVE ON THE HEALTH OF THE LOCAL PEOPLE?’
Grace: ‘Well, I think it’s not even a hypothetical question. We can just look around and see the epidemics that are taking hold. There are examples of diseases like sleeping sickness, food-borne diseases, avian influenza, and all of these are having at the moment impacts on the health and well-being of local people. In this study, we estimate that round about 6% of the sickness and death in poor countries is due to diseases which are either now being transmitted between people and [animals] or which recently jumped species from animal into humans.’
BBC: ‘OWNING LIVESTOCK IS A GREAT TOOL FOR REDUCING POVERTY IN DEVELOPING COUNTRIES. YET IF WE’RE SEEING A GREAT INCREASE IN THESE EPIDEMICS, IT SEEMS A REAL PROBLEM, DOESN’T IT? IS IT JUST SOMETHING THAT WE ARE LIKELY TO SEE MORE OF?’
Grace: ‘The trends are upwards. New diseases are emerging more rapidly and as you get more animals and more animals kept in worse conditions, you do get more disease. But at the same time, you do get more opportunities. And that’s one of the really complex things; it’s not that animals are bad or that all animals are good. It’s that there are both risks and benefits associated with keeping animals, especially in poor countries. We need to reduce the risks and increase the benefits.’
BBC: ‘DELIA GRACE FROM THE INTERNATIONAL LIVESTOCK RESEARCH INSTITUTE.’
Listen to the 4-minute-plus interview:
(06:09 to 09.52) on BBC Radio 4 Farming Today program, 7 March 2011.