The subject of epidemiology is "about the investigation of causes of health related events in the populations" (Morabia, 2004), and is as a scientific discipline relatively recent. Epidemiology can be exercised in a variety of health contexts such as clinical health care and research. It is considered a cornerstone discipline in Public Health, aimed to generate an evidence base for policy and decision making for healthy populations.
Though the scientific discipline of epidemiology is relatively new, knowledge about factors that influence epidemics dates much further back in medical history. Hippocrates described already his intuition of the association between environmental factors, human behaviors and disease, even when most people in his time (in the 4th century b.C) believed in supra-natural causes of disease. (See also the discussion forum on this)
Applied Epidemiologists, or "Field Epidemiologists", use science as the basis for intervention programmes designed to improve public health (White, 2001). Such application may then also be called 'intervention epidemiology' and even the term 'consequential epidemiology' has been phrased. This branch of epidemiology has its origin in the post graduate public health residency programme of the Centers for Disease Control and Prevention (CDC, Atlanta, USA): the 'Epidemic Intelligence Service (EIS)', that started in 1951. Since then, many countries have set up Field Epidemiology Training Programmes (FETP) and in 1995 the European Programme for Intervention Epidemiology Training (EPIET) started to train the first cohort of fellows in the 2 year full time curriculum, funded by the European Commission.
Field epidemiology aims to apply scientific methods in day to day public health field conditions in order to generate new knowledge and evidence for decision making. The context is often complex and difficult to control, which challenges study design and interpretation of study results. However, often in Public Health we lack the opportunity to perform controlled trials and we are faced with the need to design observational studies as best as we can. Field epidemiologists use epidemiology as a tool to design, evaluate or improve interventions to protect the health of a population.
For example, think of a sudden increase of mumps among teenagers in a country with high vaccine coverage. A key question to answer quite early after detecting such event is: is the mumps outbreak caused by a vaccine failure or a failure to vaccinate? Obviously a vaccine failure would require a different set of public health actions than a failure to vaccinate. Field Epidemiology includes the ability to rapidly design and execute an appropriate epidemiological study to generate reliable answers to key questions, timely enough to allow control measures to be effective. And for such a study the epidemiologist will need to get out of the office and into the field or onto the streets. For this reason, field epidemiology has yet another synonym: shoe-leather epidemiology, as opposed to armchair epidemiology.
Traditionally, core activities in field epidemiology are , design, operation or evaluation of communicable disease surveillance systems and field research to study risk factors for or distribution of communicable diseases. Since communicable diseases may rapidly spread in populations they often create the urgent need to get answers about risk factors, risk groups and effective ways to intervene. Time pressure, media attention and anxiety among public and decision makers create a classical context for the field epidemiologist to work in. They are often required tocreate ad hoc teams to help them with the investigations, and often they will have to instruct and train new team members to perform the tasks that are required for the investigation
So it makes sense that they need to have excellent and to have competences in teaching. It will therefore not be surprising that the traditional FETP requires the following training achievements:
Field epidemiology - Intervention epidemiology - Applied epidemiology - shoe leather epidemiology - consequential epidemiology