Google Trends correlation and sensitivity for outbreaks of dengue and yellow fever in the state of São Paulo.

Vitor Ulisses Monnaka,Carlos Augusto Cardim De Oliveira

doi:10.31744/einstein_journal/2021ao5969

Abstract

ABSTRACTObjective To assess Google Trends accuracy for epidemiological surveillance of dengue and yellow fever, and to compare the incidence of these diseases with the popularity of its terms in the state of São Paulo.Methods Retrospective cohort. Google Trends survey results were compared to the actual incidence of diseases, obtained from Centro de Vigilância Epidemiológica “Prof. Alexandre Vranjac”, in São Paulo, Brazil, in periods between 2017 and 2019. The correlation was calculated by Pearson’s coefficient and cross-correlation function. The accuracy was analyzed by sensitivity and specificity values.Results There was a statistically significant correlation between the variables studied for both diseases, Pearson coefficient of 0.91 for dengue and 0.86 for yellow fever. Correlation with up to 4 weeks of anticipation for time series was identified. Sensitivity was 87% and 90%, and specificity 69% and 78% for dengue and yellow fever, respectively.Conclusion The incidence of dengue and yellow fever in the State of São Paulo showed a strong correlation with the popularity of its terms measured by Google Trends in weekly periods. Google Trends tool provided early warning, with high sensitivity, for the detection of outbreaks of these diseases.

Highlights

Communicable diseases are a threat to the health of individuals, especially in developing countries.[1]. In Brazil, dengue and yellow fever represent infections of great impact on the health of the population.[2]. Early identification of communicable disease outbreaks increases the possibility of spread control with the eventual use of prevention, isolation, and treatment interventions.[3]
Due to the impact on the health of the Brazilian population, effective surveillance of dengue and yellow fever cases is extremely important for epidemic control.[3]. In the state of São Paulo, the Centro de Vigilância Epidemiológica (CVE) “Prof. Alexandre Vranjac”, a epidemiological surveillance agency in the structure of the Disease Control Coordination (CDC - Coordenadoria de Controle de Doenças), is responsible for the disclosure of periodic reports on the status of these diseases, by epidemiological weeks
The high correlation between dengue cases and Google Trends has already been identified in Indonesia,(18) Philippines,(19) and India.[20]. Using Brazilian data, Yang et al,(17) compared surveys with dengue cases provided by the Ministry of Health, on monthly periods, between January 2001 and December 2012, and found a correlation of 0.971, similar to our results

Summary

Introduction

Communicable diseases are a threat to the health of individuals, especially in developing countries.[1]. The National Contingency Plan for Dengue Epidemics, prepared by the Ministry of Health, guides the use of the relative trend of rumors on Twitter, as indicators for specific actions in response. In this sense, Google Trends,(13) a tool that analyzes the popularity of a term searched on Google,(14) over a period of time, in a location, could be useful in surveillance of dengue and yellow fever cases

Methods

Results

Discussion

Conclusion