Under surveillance

摘要

Imagine a global weather and climate forecasting system that collects data regularly in just a handful of countries, and takes measurements elsewhere only during extreme weather events. That is what today's global flu-surveillance system mostly looks like. The shortcomings of flu surveillance have long been recognized {see Nature 440,6-7; 2006), but they are attracting renewed attention following the creation in labs of strains of the H5N1 avian influenza virus that can spread between mammals.