About Weekly and Quarterly Tables (Provisional)

Weekly and quarterly data are considered provisional data. Provisional data are initially collected locally as a result of state, territorial, and local legislation and regulations that require healthcare providers, medical laboratories, and other entities to submit data on reportable conditions to state and local public health departments. The reportable conditions vary depending upon each jurisdiction’s health priorities. The reporting jurisdictions voluntarily submit case notifications for the national notifiable conditions to CDC. NNDSS data are considered provisional and subject to change each week until the data are reconciled and verified with the state and territorial data providers to be the final official incidence counts for a given notifiable condition and year. Cumulative counts of cases presented each week can increase or decrease as additional information becomes available and counts are updated. In any given year, for most conditions, cumulative provisional case counts and rates do not match finalized case counts and rates.

Page last reviewed: September 24, 2021