A public health specialist concerned with the occurrence of disease by time, place, and persons involved, epidemiology.
A person who specialises in the study of diseases in groups of people.
A physician or other specialist who studies diseases or causes of disease in relationship to a population, such as a hospital or a community. An epidemiologist deals primarily with analysis of existing data rather than data collected prospectively in an experimental design.
A specialist in the field of epidemiology.