Well, let's note right up front that epidemiologists are not infectious disease physicians.
I like to tell this little story/thought experiment:
Q: If I have a lung infection, who should I go see, an infectious disease physician or an epidemiologist?
Most people get the right answer.
But then I ask:
Q: If society has an epidemic, should we consult an infectious disease physician who treats a single patient at a time or an epidemiologist who studies diseases and makes decisions for whole populations of people?
Generally, that little light bulb comes on in a minute or two....
Anyway, from the Association of Schools and Programs in Public Health, here is a BASIC definition of the work of an epidemiologist aka "core competencies":
Epidemiology is the study of patterns of disease and injury in human populations and the application of this study to the control of health problems.
Identify key sources of data for epidemiologic purposes.
Identify the principles and limitations of public health screening programs.
Describe a public health problem in terms of magnitude, person, time and place.
Explain the importance of epidemiology for informing scientific, ethical, economic and political discussion of health issues.
Comprehend basic ethical and legal principles pertaining to the collection, maintenance, use and dissemination of epidemiologic data.
Apply the basic terminology and definitions of epidemiology.
Calculate basic epidemiologic measures.
Communicate epidemiologic information to lay and professional audiences.
Draw appropriate inferences from epidemiologic data.
- Evaluate the strengths and limitations of epidemiologic reports.
Notice the word "control" fairly early on.
In Yolo County we have TWO epidemiologists, BOTH with PhDs. It does not get any higher or better than that!