Infoveillance
Infoveillance is a type of syndromic surveillance that specifically utilizes information found online. The term, along with the term infodemiology, was coined by Gunther Eysenbach to describe research that uses online information to gather information about human behavior.
Eysenbach's work using Google Search queries led to the birth of Google Flu Trends, and other search engines have also been used. Other researchers have utilized social media sites such as Twitter to observe disease outbreak patterns. Infoveillance can detect disease outbreaks faster than traditional public health surveillance systems with minimal costs involved.
Types
Infoveillance methods may be either passive or active. Traditional infoveillance data like search engine queries and website navigation behavior are considered passive, as they attempt to recognize trends automatically, without action on the part of the internet users who are generating the data for analysis. Active infoveillance occurs when users choose to respond to a survey, enter symptoms into a website or app, or otherwise participate directly in surveillance efforts by contributing additional information.Examples
Google Health Trends
Beginning in 2008, Google used aggregated search query data to detect influenza trends and compared the results to countries' official surveillance data with the goal of predicting the spread of the flu. In light of evidence that emerged in 2013 showing that Google Flu Trends sometimes substantially overestimated actual flu rates, researchers proposed a series of more advanced and better-performing approaches to flu modeling from Google search queries. Google Flu Trends stopped publishing reports in 2015.Google also used aggregated search query data to detect dengue fever trends. Research has also cast doubt on the accuracy of some of these predictions. Google has continued this work to track and predict the COVID-19 pandemic, creating an open dataset on COVID-related search queries for use by researchers.