How’s Google doing this? Is it now indexing actual human beings, in the way it does web pages? Nah. Turns out that when you’re sick with the flu, you search for that word and other flu-related topics. Google can tell which areas are seeing a spike in flu-related searching, and from that, trends can be plotted.
Consider this chart that compares actual flu activity to searches for flu-related terms, over time:
States with more flu activity are shown in darker blue. Click on any state to see the exact level:
Right now, folks in the states of Arkansas, Mississippi, Kentucky, Delaware, Maine and Hawaii are showing “moderate” levels of flu activity. Stop searching about the flu, folks! Step away from your keyboards, have some chicken soup and get back into bed!
When you select a state, above the US map, you’ll see the trend chart change to show you flu activity for that state over time. Flu activity over time for the entire US is shown by default. You can also download data plus enter a ZIP code to find the nearest flu shot location to you.
Postscript: Techmeme has related coverage.