Why do so many new viruses begin in China?

Southern China is a breeding ground for new flu strains and viruses. The highly contagious SARS virus is just the latest to come from that region. So what is it about Southern China that makes it the ideal place for viruses and strains of influenza to develop and thrive?

New diseases arise where there are too many humans and animals living in close proximity. In the farming region of Southern China, many people have small plots of land where they keep ducks, pigs and other livestock. When so many people and animals share the same soil and air, viruses easily jump from one species to another and swap genetic material until they find a combination that makes them thrive and their hosts get very sick. The Hong Kong Flu and the Asian flu also arose from China and southeast Asia.

Deadly epidemics have arisen in other parts of the world as well. In 1918 and 1919, influenza from Spain killed 26 million people, 1.2% of the world's population at the time. And the Ebola and West Nile viruses hail from Africa. Nevertheless, China's southern region seems particularly conducive to spawning viruses, especially in areas with high concentrations of ducks.

Resources:

Australian news agencies The Age and the Sidney Morning Herald report on small-farm conditions in Southern China and their link to illness.