When I was five, I left Singapore with my family to move to the UK, travelling by boat for six weeks. Had I boarded with one of the many strains of avian flu circulating then, as now, in Asia, I would either have recovered or died en route, infecting only other passengers. Today, I often travel between my workplace in Vietnam and the UK in less than a day. Were I to bring a new, transmissible infection, I would become a vector of potentially global concern.
With globalisation of travel has come globalisation of disease. The emergence of new viruses such as the H7N9 strain of flu, reported last week to have achieved human-to-human transmission in China, is no longer a matter for the regions in which they arise. What affects Shanghai or Ho Chi Minh City today can affect London or New York tomorrow.
For more than 17 years, I have worked in Vietnam on the front line of emerging infectious diseases, such as H5N1 bird flu, which hit the country in 2004; and Sars, which spread around the world in 2003. My experience makes me convinced that H7N9 is a cause for concern.