The use of syndromic surveillance systems has evolved over the last decade, and increasingly includes both infectious and non- infectious topic areas. Public health agencies at the national, state, and local levels often need to rapidly develop new syndromic categories, or improve upon existing categories, to enhance their public health surveillance efforts. Documenting this development process can help support increased understanding and user acceptance of syndromic surveillance. This presentation will highlight the visualization process being used by CDC’s National Syndromic Surveillance Program (NSSP) program to develop and refine definitions for syndromes of interest to public health programs.

Objective: To describe the use of uni-grams, bi-grams, and tri-grams relationships in the development of syndromic categories.