Even before the public announcements of the first cases of COVID-19 in Europe, at the end of January 2020, the signals that something strange was happening were already circulating on social media. A new study by researchers at IMT School for Advanced Studies Lucca, published in Scientific reports, identified growing concerns about cases of pneumonia in posts posted on Twitter in seven countries between late 2019 and early 2020. The analysis of the posts shows that the “denunciation” came precisely from the geographical regions where the main outbreaks -they later developed.
To conduct the research, the authors first created a single database with all the messages posted on Twitter containing the keyword “pneumonia” in the seven most spoken languages of the European Union – English, German, French, Italian, Spanish, Polish and Dutch – from December 2014 to March 1, 2020. The word “pneumonia” was chosen because the disease is the most severe disease induced by SARS-CoV-2 and also because the flu season 2020 was milder than the previous ones, so there was no reason to believe that he was responsible for all the mentions and worries. The researchers then made a series of adjustments and corrections to the posts in the database to avoid overestimating the number of tweets mentioning pneumonia between December 2019 and January 2020, ie in the weeks between the World Health Organization (WHO) announcement that the first “cases of pneumonia of unknown etiology ”were identified – on 31 December 2019 – and the official recognition of COVID19 as a serious communicable disease on 21 January 2020. In particular, all tweets and retweets containing links to news about the emerging virus were removed from the database to exclude media coverage of the emerging pandemic.
The authors’ analysis shows an increase in tweets mentioning the keyword “pneumonia” in most European countries included in the study since January 2020, so as to indicate a continuing concern and public interest in cases of pneumonia. In Italy, for example, where the first blocking measures to contain COVID-19 infections were introduced on 22 February 2020, the rate of increase in pneumonia in the first few weeks of 2020 differs substantially from the rate observed in the same weeks in 2019 This means that potentially hidden hot spots were identified a few weeks before the announcement of the first local source of COVID-19 infection (February 20, Codogno, Italy). France presented a similar pattern, while Spain, Poland and the United Kingdom were 2 weeks late.
The authors also located more than 13,000 tweets related to pneumonia in the same period and found that they came from exactly the regions where the first cases of infection were later reported, such as the Lombardy region of Italy, Madrid, Spain. and Île de France.
Following the same procedure used for the keyword ‘pneumonia’, the researchers also produced a new data set containing the keyword ‘dry cough’, one of the other symptoms later associated with COVID-19 syndrome. Even then, they observed the same pattern, namely an abnormally and statistically significant increase in the number of word entries in the weeks leading up to the increase in infections in February 2020.
“Our study adds to existing evidence that social networks can be a useful tool for epidemiological surveillance. They can help intercept the first signs of a new disease before it proliferates undetected and also track its spread,” says Massimo. Riccaboni, tenured professor of economics at the IMT School, who coordinated the research.
This is especially true in a situation like the current pandemic, when losses in identifying early warning signals have left many national governments blind to the unprecedented scale of the approaching public health emergency. In a successive phase of the pandemic, monitoring of social networks could help public health authorities mitigate the risks of recurrence of the contagion, for example by taking stricter measures of social distancing if infections appear to increase or vice versa, by relaxing them in other regions. These tools could also pave the way for an integrated epidemiological surveillance system managed globally by international health organizations.
###
The paper “Early Warnings of Outbreaks of COVID-19 in Europe on Social Networks” is available after publication at: http: // www.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of press releases posted on EurekAlert! through contributing institutions or for the use of any information through the EurekAlert system.