Google have come up with an innovative use of their search engine.  They have noticed that the number of people making queries like ‘flu symptoms’ is strongly correlated with the number of doctors visits due to the flu in that region.

Google explain their work  and provide a link to this paper (pdf) from Ginsberg et al which gives more details (including a brief mention of other similar studies, some of which use Yahoo! data). 

At first look this result might seem quite obvious.  If a region is in the depths of a flu epidemic it’s hardly surprising that more people than average will search for information about relevant symptoms.

The real power of Google’s research is that the information contained in the queries appears to have predictive power.  In other words they can spot an impending epidemic before it happens. 

According to Ginsberg et al the new Google methods can give useful information some two weeks prior to the traditional monitoring methods by the Centre for Disease Control and Prevention (CDC).  They stress that traditional methods still have their place and are not calling for their new methods to replace them. 

However, they hope that their approach could be very useful for medical authorities in planning for an epidemic before it occurs.  I imagine this would enable the early ordering and deployment of antivirals, for example.

They consider how their approach might fare during a pandemic and stress that their method has not been tested in this scenario.  It may be that heightened public awareness of the flu at such a time will invalidate their method (searches by the ‘concerned well’ may swamp those with early genuine symptoms).  However, if their method is useful in such a scenario it could save many lives. 

Lloyd’s Emerging Risks team have produced a report on Pandemics (pdf, 408kb) and are continuing to monitor this subject for developments.

In any case, Ginsberg et al state that seasonal flu, which occurs annually, is still responsible for up to half a million deaths every year, so any reduction in mortality from this cause would be welcome.

Tags: Flu, Pandemic

This entry was posted by Trevor Maynard on Thursday, January 22nd, 2009 at 12:17 pm and is filed under Exposure Management.