Surveillance of Sexually Transmitted Infections: Exploring the Utility of Internet Search Engine Data

National surveillance of sexually transmitted infections (STIs) relies on mandatory case reporting, a system that produces data that is often incomplete and suffers from delays in reporting. These issues result in missed opportunities to identify and respond to trends in disease as well as limited ability to guide STI control. As the internet is a portal for free and anonymously available health information, search engine data may provide an additional venue for surveillance efforts. New, more robust, surveillance methods may allow for significant improvements, particularly in timeliness, flexibility and sensitivity. Google Trends allows the download of de-identified search engine data trends, which can be used to investigate the implications of trends in STI-related search terms in relation to STI rates. While there is much that remains unknown, such as search engine user characteristics, content of searches, and feasibility and acceptability of integration of the new method into public health systems, it is important to explore this innovative tool and its potential application to STI surveillance. This three-study investigation examined the utility of Google Trends applied to STI surveillance by: 1) examining the association between search term volume and STI rates; 2) surveying surveillance workers to determine the overall interest and perceived utility of Google Trends for STI surveillance; and 3) surveying internet users to determine the content of STI-related searches.