title: Digital disease detection: A systematic review of event-based internet biosurveillance systems.
abstract: Internet access and usage has changed how people seek and report health information. Meanwhile,infectious diseases continue to threaten humanity. The analysis of Big Data, or vast digital data, presents an opportunity to improve disease surveillance and epidemic intelligence. Epidemic intelligence contains two components: indicator based and event-based. A relatively new surveillance type has emerged called event-based Internet biosurveillance systems. These systems use information on events impacting health from Internet sources, such as social media or news aggregates. These systems circumvent the limitations of traditional reporting systems by being inexpensive, transparent, and flexible. Yet, innovations and the functionality of these systems can change rapidly.
  
  
  
  To update the current state of knowledge on event-based Internet biosurveillance systems by identifying all systems, including current functionality, with hopes to aid decision makers with whether to incorporate new methods into comprehensive programmes of surveillance.
  
  
  
  A systematic review was performed through PubMed, Scopus, and Google Scholar databases, while also including grey literature and other publication types.
  
  
  
  50 event-based Internet systems were identified, including an extraction of 15 attributes for each system, described in 99 articles. Each system uses different innovative technology and data sources to gather data, process, and disseminate data to detect infectious disease outbreaks.
  
  
  
  The review emphasises the importance of using both formal and informal sources for timely and accurate infectious disease outbreak surveillance, cataloguing all event-based Internet biosurveillance systems. By doing so, future researchers will be able to use this review as a library for referencing systems, with hopes of learning, building, and expanding Internet-based surveillance systems. Event-based Internet biosurveillance should act as an extension of traditional systems, to be utilised as an additional, supplemental data source to have a more comprehensive estimate of disease burden.
authors.affiliation: Yale Primary Care Residency Program, Yale University School of Medicine, 1450 Chapel Street, New Haven CT 06511, United States. Electronic address: jesse.oshea@yale.edu.
authors.forename: Jesse
authors.initials: J
authors.lastname: O'Shea
mesh_terms: D055877:Biosurveillance; D003141:Communicable Diseases / Q000175:diagnosis*; D016208:Databases, Factual; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D006801:Humans; D020407:Internet
keywords: Biosurveillance; Disease surveillance; Public health