Early warnings of COVID-19 outbreaks across Europe from social media?

TL;DR

This study demonstrates that social media data, specifically Twitter, can serve as an early warning system for COVID-19 outbreaks in Europe by detecting public concern signals before official reports.

Contribution

It introduces a method to analyze social media for early outbreak detection, highlighting the potential for integrated digital surveillance systems.

Findings

Social media signals preceded official outbreak announcements.

Geographical regions with early concern signals matched later infection hotspots.

Social media can help geo-localize chains of contagion.

Abstract

We analyze data from Twitter to uncover early-warning signals of COVID-19 outbreaks in Europe in the winter season 2019-2020, before the first public announcements of local sources of infection were made. We show evidence that unexpected levels of concerns about cases of pneumonia were raised across a number of European countries. Whistleblowing came primarily from the geographical regions that eventually turned out to be the key breeding grounds for infections. These findings point to the urgency of setting up an integrated digital surveillance system in which social media can help geo-localize chains of contagion that would otherwise proliferate almost completely undetected.