Using Google Trends for Influenza Surveillance in South China

Min Kang,Shannon Rutherford,Fen Yang,Jianfeng He,Haojie Zhong,Alessandro Vespignani

doi:10.1371/journal.pone.0055205

Min Kang, Shannon Rutherford + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0055205

Copy DOI

Abstract

BackgroundGoogle Flu Trends was developed to estimate influenza activity in many countries; however there is currently no Google Flu Trends or other Internet search data used for influenza surveillance in China.Methods and FindingsInfluenza surveillance data from 2008 through 2011 were obtained from provincial CDC influenza-like illness and virological surveillance systems of Guangdong, a province in south China. Internet search data were downloaded from the website of Google Trends. Pearson's correlation coefficients with 95% confidence intervals (95% CI) were calculated to compare surveillance data and internet search trends. The correlation between CDC ILI surveillance and CDC virus surveillance was 0.56 (95% CI: 0.43, 0.66). The strongest correlation was between the Google Trends term of Fever and ILI surveillance with a correlation coefficient of 0.73 (95% CI: 0.66, 0.79). When compared with influenza virological surveillance, the Google Trends term of Influenza A had the strongest correlation with a correlation coefficient of 0.64 (95% CI: 0.43, 0.79) in the 2009 H1N1 influenza pandemic period.ConclusionsThis study shows that Google Trends in Chinese can be used as a complementary source of data for influenza surveillance in south China. More research in the future should develop new models using search trends in Chinese language to estimate local disease activity and detect early signals of outbreaks.

Highlights

Disease surveillance plays a key role in controlling and responding to influenza epidemics and pandemics [1]
This study shows that Google Trends in Chinese can be used as a complementary source of data for influenza surveillance in south China
To measure the influenza epidemic situation in Guangdong, both influenza-like illness (ILI) surveillance and influenza virus surveillance are used by Guangdong CDC

Summary

Introduction

Disease surveillance plays a key role in controlling and responding to influenza epidemics and pandemics [1]. Conventional surveillance for influenza is routinely recommended to monitor influenza-like illness (ILI) and influenza virus infections. Such surveillance involves the collection and analysis of data from clinics and laboratories. This traditional mode of surveillance is dependent on case reporting and medical records to track disease activity and time delays in reporting and case confirmation can slow detection of outbreaks or increases in influenza in the community. Google Flu Trends was developed to estimate influenza activity in many countries; there is currently no Google Flu Trends or other Internet search data used for influenza surveillance in China

Methods

Results

Conclusion