Calculated Case Counting Date | Core Data Elements for Case Notification

Public health agencies assign a date to each reported case for the purposes of tracking disease incidence over time. Without a standardized approach, significant variation across jurisdictions makes it difficult to accurately compare or aggregate data at the national level. The Calculated Case Counting Date (CCCD) addresses this by establishing a consistent algorithm — applied across agencies and conditions — that identifies the most epidemiologically relevant date of disease occurrence based on available information for each case. 

The CCCD is defined as the most epidemiologically relevant date representing when disease occurred, assigned according to a consistent algorithm across public health agencies and conditions based on the best available information for each case. 

The CCCD should be assigned the value of the earliest of the available component dates: 

• Symptom onset date 

• Clinical diagnosis date 

• Earliest specimen collection date of a positive lab result 

• Result date of first positive lab result 

• Date first received by public health agency 

• Date entered or record initiated