Some are MDs, but most have a Ph.D or MPH (Master of Public Health) instead or in addition to a MD. Epidemiology is a science and one that is not well covered in medical schools.
Epidemiology is a science as much as for instance infectiology is a science. An aggregate of best practices relying only partially on hard (experimental or mathematical) science. For example IMO, the Bradford Hill criteria are backed by informal reasoning and although seemingly trivially logical, are very much dogmatic in nature.
It's true that many epidemiologists are not MDs, though. I formulated my thoughts badly in that regard.
It's true that many epidemiologists are not MDs, though. I formulated my thoughts badly in that regard.