On the outskirts of Shunde, an industrial town in Guangzhou, you can find some possible answers to why China has been the breeding ground for so many lethal viruses - if you can stand the smell that is.
This "factory to the world" is across the border from Hong Kong and accelerating industrialisation has also touched the world of Chinese farming to create an alarming hybrid.
Traditionally, Chinese farming was primarily concerned with little more than subsistence living, with families living close to their animals on tiny plots of land. However, in Shunde and much of Guangdong province there is now a semi-industrialised version of East meets West, with thousands of ducks, geese and chickens living in shacks perched over fish-farm ponds.
The fish live on the waste from the birds and the pigs that are tightly packed into rat-infested pens built on the narrow stretches of land, which frame the ponds.
Illiterate tenant farmers, invariably migrants from China's poorer provinces, sell their produce to the filthy markets and booming restaurants that cater to an ever-richer clientele. Few can afford antibiotics and even fewer can afford professional veterinary care.