Figure 3
From: Early warnings of COVID-19 outbreaks across Europe from social media
source software QGIS 3.10 LTS (https://qgis.org/it/site/).
Anomalous evolution and geo-localization of tweets concerned with dry cough posted across Europe. (a) Evolution of the cumulative number of dry cough-related tweets posted in 7 European countries since November 2018. (b) Geographic distribution of unique users discussing dry cough in the winter season between 1 December 2019 and 30 January 2020. The map was generated using the open-
