# Epidemiology ## Identification Epidemiology is the systematic study of the distribution and determinants of health-related states or events in populations and the application of that study to control health problems. It is a core public-health discipline grounded in observation, comparison, causal reasoning, statistics, and field investigation. ## Contact tracing Contact tracing is an epidemiological intervention. It combines a case definition and infectious-period estimate with interviews, encounter information, notification, testing, monitoring, and support. [[Contact Tracing]] can accelerate or supplement some steps, but proximity data alone cannot determine whether infection or transmission occurred. ## Notebook relationship [[Scanned_20260730-1946]], PDF pages 13 and 16, place contact tracing inside a much wider identity-and-infrastructure thesis. The notebook did not separately name epidemiology, so this note supplies the disciplinary framework necessary to distinguish public-health practice from the author's broader systems interpretation. ## Classification and ethical boundary Epidemiology necessarily groups observations by person, place, time, exposure, and outcome. Those categories are analytical tools, not judgments of human worth. When health categories become persistent proxies for moral status, identity, eligibility, movement, or affiliation, the system crosses toward [[Social sorting]]. [[Social Darwinism]] is a historical ideology of hierarchy and competition, not a scientific consequence of epidemiology. ## Relationships [[COVID-19]] · [[SARS-CoV-2]] · [[Severe acute respiratory syndrome|SARS]] · [[Contact Tracing]] · [[Google-Apple Exposure Notification]] · public-health surveillance · [[Social sorting]] ## Sources - [CDC — Principles of Epidemiology](https://archive.cdc.gov/www_cdc_gov/csels/dsepd/ss1978/lesson1/section1.html) - [WHO — Contact tracing for responders](https://www.who.int/news-room/questions-and-answers/item/coronavirus-disease-%28covid-19%29-contact-tracing-for-responders)