Using Social Media and Internet Data for Public Health Surveillance: The Importance of Talking

D espite progress in public health and the biomedical sciences, infection has yet to be vanquished: vaccine-preventable diseases continue to be transmitted; pandemics occur; previously unknown pathogens emerge; contaminated foods and food products are traded and consumed; and the specter of a post-antibiotic era looms ever larger. Bioterrorism is, and will remain, a danger. Infectious disease is both a national and an international security issue and represents an important threat to human health and well-being. In order to confront these and related threats, detailed data regarding the global ebb and flow of disease are needed. Over many decades, surveillance methods (often termed “indicator-based” methods) have been developed and refined to provide disciplined, standardized approaches to acquiring and recording important information. More recently, ubiquitous and unstandardized data collected from the Internet have been used to gain insight into emerging disease events. Although this approach— known as “Internet-based biosurveillance,” “digital disease detection,” or, more simply, “event-based” surveillance—has been described and