Abstract
Introduction: Dengue has become an endemic problem in India with frequent outbreaks reported from several parts of the country every year. A passive surveillance system is unable to deal with the mounting number of cases every year. In the last couple of years the internet has become a valuable tool to access healthcare related information.
Aim: To analyse the correlation between dengue cases reported every year and annual Internet search data for the term "dengue" obtained via Google trends.
Materials and Methods: Dengue incidence data was collected from the National Vector Borne Disease Control Programme (NVBDCP) database alongside relative search volumes from Google trends for the term "dengue" and correlation was estimated by calculating Pearson's correlation coefficient.
Results: The data was analysed from the year 2004 up to year 2017. In this period, a total of 693,318 cases of dengue were reported from India. Relative search volume for dengue searches on Google trends was found to be highly correlated with dengue incidence data. Google trends indicate a seasonal pattern showing maximum search volume in the monsoon months, which also coincides with most dengue cases. Internet based searches and Google trends can be used in addition to traditional surveillance methods for predicting disease outbreaks.
Conclusion: The analysis shows an overall strong positive correlation between incidence of dengue cases and Google trends indicating the usefulness of internet searches in gathering healthcare related information during the time of outbreaks. Internet based searches could be an additional tool along with classical surveillance methods for accurately predicting disease outbreaks in resource poor settings.