The H1N1 flu pandemic last year came out of nowhere. Well, not exactly — H1N1 first emerged in human beings in Mexico. But that wasn't where most influenza experts were looking. The focus had been on southeast Asia, where the H5N1 avian flu had been infecting — and killing — human beings for the past few years. Most flu pandemics begin in that part of the world, where dense populations of people and animals commingle. H1N1 was different, however, and the world paid the price.

But we may not have learned our lesson