Final answer:
Epidemiology is used to track and understand the distribution and causes of diseases in populations, develop public health strategies, and reduce the incidence of diseases. It has evolved from focusing primarily on infectious diseases to encompass a wider range of health concerns, including noninfectious diseases and environmental health factors.
Step-by-step explanation:
Epidemiology has been used throughout the ages to study and understand the patterns, causes, and effects of health and disease conditions in defined populations. Epidemiologists collect data on disease frequency, track the spread to identify the original mode of transmission, and work in collaboration with historians on disease evolution. The information gathered from various sources such as clinical records, patient interviews, and surveillance is crucial for developing public health strategies like vaccinations and policies to reduce disease incidence or prevent its spread, particularly in the case of outbreaks where rapid investigation is necessary to control the situation.
This science, which underlies public health, has transcended its early focus on infectious diseases to include noninfectious diseases, environmental connections to diseases, and accidental injuries. Epidemiological methods have grown more sophisticated over time, and significant contributions have been made in the form of population-based health management. To appreciate this, one can look to pioneers like Richard Doll and Austin Bradford Hill, who were among the first to use epidemiology to identify links between tobacco smoking and lung cancer, marking the expansion of epidemiology beyond infectious diseases.