Background
deaths
VIRUS INFECTION, INFLUENZA
In the United States, an estimated 9 to 41 million annual illnesses are attributable to influenza virus infection, resulting in up to 710,000 hospitalizations and 52,000 deaths annually [Using commercial wearable sensors (Fitbit [Fitbit LLC]), we previously demonstrated that nationwide mobility (measured as total daily steps in a US population) decreased owing to ILI symptoms and that ILI burden (determined by the difference in total daily steps) was associated with care-seeking behaviors, the number of workdays missed, and self-reported overall health [