[7:20 pm, 25/03/2024] Yousra Alghamdi: Epidemiology is a discipline which has evolved with the changes taking place in society and the emergence of new diseases and new discipline related to epidemiology.[7:20 pm, 25/03/2024] Yousra Alghamdi: Public health surveillance; the ongoing, collection, analysis, interpretation, and dissemination of health information to help guide health decision making and actions.The purpose of public health surveillance is to portray ongoing patterns of disease occurrences and disease potential.This is done through systematic collection and evaluation of morbidity and mortality reports and other relevant health information.Other sources of health-related data that are used for surveillance include public health program data such as immunization coverage in a community, disease registries, and health surveys.Public health surveillance traditionally focuses on communicable diseases.