The utility of "Google Trends" for epidemiological research: Lyme disease as an example.

Internet search engines have become an increasingly popular resource for accessing health-related information. The key words used as well as the number and geographic location of searches can provide trend data, as have recently been made available by Google Trends. We report briefly on exploring this resource using Lyme disease as an example because it has well-described seasonal and geographic patterns. We found that search traffic for the string "Lyme disease" reflected increased likelihood of exposure during spring and summer months; conversely, the string "cough" had higher relative traffic during winter months. The cities and states with the highest amount of search traffic for "Lyme disease" overlapped considerably with those where Lyme is known to be endemic. Despite limitations to over-interpretation, we found Google Trends to approximate certain trends previously identified in the epidemiology of Lyme disease. The generation of this type of data may have valuable future implications in aiding surveillance of a broad range of diseases.