Use of Internet Search Queries to Enhance Surveillance of Foodborne Illness

As a supplement to or extension of methods used to determine trends in foodborne illness over time, we propose the use of Internet search metrics. We compared Internet query data for foodborne illness syndrome related search terms from the most popular 5 Korean search engines using Health Insurance Review and Assessment Service inpatient stay data for 26 International Classification of Diseases, Tenth Revision, codes for foodborne illness in South Korea during 2010-2012. We used time-series analysis with Seasonal Autoregressive Integrated Moving Average (SARIMA) models. Internet search queries for "food poisoning" correlated most strongly with foodborne illness data (r = 0.70, p<0.001); furthermore, "food poisoning" queries correlated most strongly with the total number of inpatient stays related to foodborne illness during the next month (beta = 0.069, SE 0.017, p<0.001). This approach, using the SARIMA model, could be used to effectively measure trends over time to enhance surveillance of foodborne illness in South Korea.