Typically, the GIS Team at the Times does great work with maps, using timeline sliders, and appropriate levels of granularity to best tell their story. This time, however, I think they've fallen short. First off, rather than using circles, which we all know are almost impossible to compare to one another, why not just fill in the states and countries with the appropriate color shades showing the number of cases? Or, better yet, go granular and show the data at county/province level.
Here's an old map from NYTimes showing state and county level voting results over time. You can select which view you want from the menus on the left side of the map. I think this approach would be better for the flu map, as there's a time component they could use to show the spread of the flu. In addition, the county/province level would provide a clearer picture of the exact places impacted by the flu. For example, in Mexico, are most of the cases in Mexico City, or some other part of the country?
