2023-2024 U.S. Flu Season: Preliminary In-Season Burden Estimates - CDC
Each week CDC calculates a lower estimate and an upper estimate of flu-related hospitalizations that have occurred since the beginning of the season (October 1, 2023). These are updated each week and are compared to end-of-season estimates of flu-related hospitalizations from previous flu seasons. Limitations The estimates of the preliminary, cumulative burden of seasonal influenza are subject to several limitations: The cumulative rate of lab-confirmed flu-related hospitalizations reported during the season may be an underestimate of the rate at the end of the season because of identification and reporting delays. Rates of lab-confirmed flu-related hospitalizations are adjusted for the frequency of flu testing and the sensitivity of flu diagnostic assays. However, data on testing practices during the current flu season are not available in real-time. To make these estimates, CDC uses data on testing practices from the past flu seasons as a proxy. If more testing is being don