Evaluation of rates of laboratory-confirmed influenza hospitalization in rural and urban census tracts over eight influenza seasons.

The burden of influenza in rural areas is largely unstudied. Rural populations may be vulnerable yet isolated from circulating virus. Laboratory-confirmed influenza hospitalizations in rural Colorado census tracts over eight influenza seasons were inconsistently distributed across seasons. Rural rates were, on average, lower than urban rates. Race, ethnicity, poverty, health insurance coverage, and distance from a hospital accounted for rate differences. Our interpretation is: 1) influenza regularly circulates in urban areas and inconsistently spreads to rural areas, 2) demographic and socioeconomic factors drive morbidity in exposed populations, and 3) public health interventions targeting high-risk urban census tracts may be beneficial.