Epidemiologists are similar to medical detectives in that they investigate who gets diseases and why. They receive training after four years of college and two to four years of master's or doctoral studies. They could specialise in something like environmental epidemiology, which studies the relationship between environmental exposure and disease. 

Most epidemiologists work for federal, state, or local governments, such as the Centers for Disease Control and Prevention or a local health department. They investigate the prevalence, distribution, and causation of disease in human populations and devise methods of prevention and management. 

Epidemiologists gather, analyse, and interpret data, write reports, and communicate their results both orally and in writing. They must be proficient in statistics, analysis, and communication. 

Their work may be carried out in universities, hospitals, research centres, or pharmaceutical firms. An epidemiologist, like any investigator, may go on location to learn more about the cause and effect of a disease in a specific community. He or she may question people in order to determine who is most at risk and to build theories about how a specific disease spreads. 

The results of both laboratory and field study could be published in a medical publication. They may also result in the development of new public health programmes. From determining the problem to arguing for therapy, an epidemiologist must be patient, persistent, and precise.