A short while ago, I mentioned Google Trends as a good way of tracking what goes on around the Internet. The answer is often “nothing much,” but that’s what goes on in most internet users’ brains in the first place.

Now, Google has taken it one step further by launching Google Flu Trends, a Google service devoted to tracking the spread of influenza throughout the United States. How does it work? Well, Google hasn’t yet managed to send search spiders into our immune system… yet… but instead Google Flu Trends uses search data to make estimations about how many people are sick.

It works like this: People sick with the flu are more likely to search for flu remedies and symptoms than people who aren’t. Therefore, as the number of flu-related searches increase in a region, it’s likely that the number of people sick with the flu has also increased. Google Flu Trends claims to be two weeks faster in reporting flu sickness rates than the CDC.

According to the CDC, the flu strikes as much as twenty percent of the US population each year, killing 36,000. How can Google Flu Trends help prevent this? It seems uncertain as of yet, but perhaps by letting the population of the U.S. know in near real-time where the flu is, people in areas with higher concentrations of the flu might be more motivated to get a flu shot.

This isn’t all that Google has up its sleeve, however. Apparently the company has invested “more than $14 million … in the global fight against diseases such as bird flu, HIV, malaria and tuberculosis”. According to the Flu Trends entry in Google’s blog, Google has high hopes for this kind of technology, saying it might even help prevent pandemics in the future.

In the meantime, I wonder if we’ll ever get stats on how many pathophobes set Google Flu Trends as their homepage.

UPDATE: I now note that the phrase “flu symptoms” is the highest search term on Google trends. Although I’d be surprised if Google didn’t expect that one.