General Principles of Epidemiology

Samantha M. Tweeten, PhD, MPH Epidemiologist

Epidemiology and Immunization Services Branch
Health and Human Services Agency
County of San Diego
San Diego, CA

October 3, 2014


Epidemiology—the study of the frequency, distribution, cause, and control of disease in populations—forms the basis of all health-related studies. It provides the background for interventions to reduce transmission of infecting organisms, reduce the number of healthcare-associated infections, and protect healthcare providers from infection. Understanding the relationships of host, environment, and organism will aid the infection preventionist in designing studies to determine the cause of healthcare-associated infections and design interventions.