Exploring Usability of School Closure Data for Influenza-Like Illness Surveillance

We compared tempOral patterns of respiratory illness-related unplanned school closures (USC) with influenza-like illness (ILI) data from outpatient provider visits to determine usability of these data for additional insight regarding ILI activity. We found significant correlation between USC and ILINet data (R= 0.54 with p-value <0.0001). The occurrence pattern of respiratory illness-related USCs similarly corresponded with that of ILI activity regardless of the severity of influenza season. This suggests that monitoring USCs can be a useful addition to existing influenza surveillance systems, particularly during severe influenza seasons when respiratory illness-related USCs may occur more frequently.