Most modern-day societies are highly mobile, with people journeying thousands of miles by road, rail and air for work, family and fun. But as well as packing their suitcases, these travellers also bring along unwanted biological baggage: viruses. Nearly four million people travel between states in the US for work, as shown in this map, ranging from just a handful (blue lines) to 10,000 (red) moving between major cities every single day. By mapping these travel networks onto patterns of flu virus infection, researchers have found that the spread and evolution of the virus across the country closely lines up to commuter routes. Thousands of people die from flu every year in the US alone, and the spread of outbreaks can be tricky to predict. Understanding more about how infections spread across state lines through travel networks helps public health teams plan the best way to keep them under control.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.