Monitoring listeria using infoveillance and notified cases. Results from Italy, Spain, Germany, and France

Background: Conducting a monitoring study using infoveillance and notified cases might facilitate a proactive and data-driven approach to public health surveillance, risk assessment, and outbreak response. The purpose of this study was to evaluate the potential correlation and association between the annual epidemiological trend of reported cases of listeriosis in humans and online searches performed by users on platforms such as Google Trends (GT) and Wikipedia. Methods: Pearson correlation coefficient (r) between Wikipedia pages and GT topics. Linear regression models were performed considering the number of views of Wikipedia pages and the notified cases of Listeria by ECDC for the four most reporting countries (Italy, Spain, Germany, and France. The study period was from July 2015 to December 2023. Results: Statistically significant correlations were found between all Wikipedia page views and GT (p-value < 0.001). Further, a positive association is observed between the annual ECDC data on notified cases in Italy, Spain, and Germany (p-value < 0.05) and the corresponding Wikipedia pages. Conclusions: There is a significant and meaningful temporal correlation between Wikipedia page views and GT related to Listeria monocytogenes, and this correlation aligns with the reported cases of Listeria infection according to ECDC data. The findings contribute to understanding the potential utility of online search behavior as a proxy for public health-related events.