It appears the world's most popular search engine discovered the swine flu outbreak in Mexico almost a week before most of the world did.
The only problem is, no one was paying attention.
For months, Google has been tracking and releasing data on the number of U.S.-based flu-related queries made to the search engine. The theory is that when people get sick, they go online to search for information. Since tracking those queries provides a near-real-time picture of how many people are sick, the data can spot outbreaks more quickly than conventional methods.
This week, Google released data on the number of flu-related Web queries made by users in Mexico. The data shows a sharp spike in the number of queries, especially in Mexico City, beginning early in the week of April 19. By the end of that week, Mexican health officials had sounded the alarm and swine flu had become a global concern.
But while the data was there, no one knew to look for it until after the outbreak became major news, at which point the head start it could have given health officials was gone.
In the United States, Google can check the accuracy of its results against data from the Centers for Disease Control and Prevention. With the Mexican data, Google engineers note, the search engine has been unable to perform such checks.
Last week, the CDC asked Google to look back at its search queries from Mexico. The search engine released the data to the public on Wednesday.
“While we would prefer to validate this data and improve its accuracy, we decided to release an early version today so that it might help public health officials and concerned individuals get an up-to-date picture of the ongoing swine flu outbreak,” Google engineers wrote in a blog post accompanying the data.
Google plans to continue updating its Mexican flu estimates and monitor the situation in the United States. However, the search engine's models must also filter out the onslaught of flu-related queries now being made by healthy people looking for information about what has become a global crisis.