Original Research Monitoring public interest toward pertussis outbreaks: an extensive Google Trendsebased analysis V. Gianfredi a , N.L. Bragazzi b,* , M. Mahamid c,d , B. Bisharat c,d,e , N. Mahroum f , H. Amital f , M. Adawi g a School of Specialization in Hygiene and Preventive Medicine, Department of Experimental Medicine, University of Perugia, Perugia, Italy b Postgraduate School of Public Health, Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy c EMMS Nazareth Hospital, Nazareth, Israel d Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel e The Society for Health Promotion of the Arab Community, The Max Stern Yezreel Valley College, Nazareth, Israel f Zabludowicz Center for Autoimmune Diseases, Department of Medicine B, Sheba Medical Center, And Sackler Faculty of Medicine, Tel Aviv University, Ramat Gan, Israel g Padeh and Ziv Medical Centers, Azrieli Faculty of Medicine, Bar-Ilan University, Zefat, Israel article info Article history: Received 21 May 2018 Received in revised form 22 July 2018 Accepted 5 September 2018 Keywords: Pertussis Google Tends Infodemiology Fast data Big data abstract Objectives: Pertussis is a vaccine-preventable disease. Despite this, it remains a major health problem among children in developing countries and in recent years, has re- emerged and has led to considerable outbreaks. Pertussis surveillance is of paramount importance; however, classical monitoring approaches are plagued by some shortcomings, such as considerable time delay and potential underestimation/underreporting of cases. Study design: This study aims at investigating the possibility of using Google Trends (GT) as an instrument for tracking pertussis outbreaks to see if infodemiology and infoveillance approaches could overcome the previously mentioned issues because they are based on real-time monitoring and tracking of web-related activities. Methods: In the present study, GT was mined from inception (01 January 2004) to 31 December 2015 in the different European countries. Pertussis was searched using the ‘search topic’ strategy. Pertussis-related GT figures were correlated with the number of pertussis cases and deaths retrieved from the European Centre for Disease prevention and Control database. Results: At the European countries level, correlation between pertussis cases and GT-based search volumes was very large (ranging from 0.94 to 0.97) from 2004 to 2015. When examining each country, however, only a few reached the threshold of statistical significance. * Corresponding author. Postgraduate School of Public Health, Department of Health Sciences (DISSAL), University of Genoa, Via Antonio Pastore 1, Genoa 16132, Italy. E-mail address: robertobragazzi@gmail.com (N.L. Bragazzi). Available online at www.sciencedirect.com Public Health journal homepage: www.elsevier.com/puhe public health 165 (2018) 9 e15 https://doi.org/10.1016/j.puhe.2018.09.001 0033-3506/© 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.