Epidemiology is derived from the Greek term epi, meaning on or at, demos, meaning people, and logos, meaning study. In other words, epidemiology is the study of what happens to a group of people. Many definitions have been proposed, but the one below best captures the fundamental concepts of epidemiology and the spirit of public health. Epidemiology is the study of the distribution and determinants of health-related conditions or events in specific populations and the application of this knowledge to disease prevention. It is a cornerstone of public health that influences evidence-based policy and practice by identifying disease risk factors and priorities for preventive health care. Epidemiologists assist in study design, data collection, statistical analysis, interpretation, and dissemination. Epidemiology has helped to develop methods for clinical research, public health research, and, to a lesser extent, basic biological research.
An internist, often known as an internal medicine doctor, is a physician who specializes in internal medicine. Internal medicine focuses on the prevention, diagnosis, and treatment of injuries and diseases. Internal medicine specialists are trained to diagnose and treat common diseases, acute and chronic illnesses, and complex diagnostic problems. Internal medicine doctors focus on treating adults as part of general medicine, while they may have additional training in specialties such as infectious diseases. Infectious disease medicine is a discipline of internal medicine that focuses on the diagnosis and treatment of infections. While general practitioners and doctors of other specialties treat most infections, infectious disease physicians are regularly called upon to help diagnose unknown illnesses and treat complex, unusual, or severe infections. Infectious disease medicine requires a thorough understanding of how bacterial, viral, fungal, and parasitic diseases manifest clinically in humans, as well as knowledge of antimicrobials, antibiotic resistance, vaccines, and other immunobiological agents.