1. Introduction to Epidemiology.pdf

Introduction to Epidemiology Emmanuel P. Hernandez, DVM, DVSc Department of Veterinary Paraclinical Sciences College of Veterinary Medicine University of the Philippines Los Baños Public Health “The science and art of preventing disease, prolonging life, and promoting...

Introduction to Epidemiology Emmanuel P. Hernandez, DVM, DVSc Department of Veterinary Paraclinical Sciences College of Veterinary Medicine University of the Philippines Los Baños Public Health “The science and art of preventing disease, prolonging life, and promoting health through the organized efforts and informed choices of society, organizations, public and private communities, and individuals.” - CEA Winslow  A Public Health Approach Risk Factor Intervention Surveillance Implementation Identification Evaluation 4 Epidemiology as Basic Science of Public Health Quantitative discipline that relies on a working knowledge of probability, statistics, and sound research methods Method of causal reasoning based on developing and testing hypotheses grounded in such scientific fields as biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events. Cholera — A Public Health Approach Cholera, a fatal intestinal disease, was rampant during the early 1800s in London, causing death to tens of thousands of people in the area. Cholera was commonly thought to be caused by bad Photo: TJ Kirn, MJ Lafferty, CMP Sandoe, and R Taylor, Dartmouth Medical School air from rotting organic matter. 6  John Snow, Physician John Snow is best known for his work tracing the source of the cholera outbreak and is considered the father of modern epidemiology. Photo: London School of Hygiene and Tropical Medicine 7 Epidemiology — What is the Problem? Cluster of Cholera Cases, London — 1854 Image: The Geographical Journal 8 Risk Factor Identification — What Is the Cause? Cluster of Cholera Cases and Pump Site Locations Image: The Geographical Journal 9 Intervention Evaluation — What Works? Through continuous research, Snow understood what interventions were required to stop exposure to the contaminated water supply on a larger scale, and stop exposure to the entire supply of contaminated water in the area 10 Implementation — How Do You Do It? John Snow’s research convinced the British government that the source of cholera was water contaminated with sewage Photo: Justin Cormack 11  Epidemiology Comes from the Greek words epi, meaning on or upon, demos, meaning people, and logos, meaning the study of. Study of disease in populations and of factors that determine its occurrence Veterinary Epidemiology Veterinary epidemiology deals with the investigation of diseases, productivity and animal welfare in populations. It is used to describe the frequency of disease occurrence and how disease, productivity and welfare are affected by the interaction of different factors or determinants. 12  Uses of Epidemiology Determination of the origin of disease on which the cause is unknown Investigation and control of a disease whose cause is either unknown or poorly understood Acquiring information on the ecology and natural history of the disease Planning, monitoring, and assessment of disease control programs Assessing the economic effects of the diseases and of its control Making individual decisions 13  Veterinary Epidemiology The ultimate goal is to control a disease problem, reduce productivity losses, and improve animal welfare. 14