According to Professor Gabriel Leung, the head of the Department of Community Medicine at Hong Kong University, the spread of disease does not just work in one direction. Virologists, he said, are now looking at how viruses pass, not just from animals to humans, but from humans to animals and then back to humans again.
"SARS was a wake up call, not just to Hong Kong but to the rest of the world and what it showed us is that the world of infectious diseases is ever present. Microbes will always be with us and we can never proclaim -- as we did in the 60s and 70s -- that the book on infectious diseases is closed," Leung said.
"It reminds us that human health and veterinary health are one and the same thing and we need to be constantly vigilant," he added. "We are linked to animals not just by contact but also by the food chain and the latest horse meat scandal is a good illustration of that."