Who are epidemiologists?

Epidemiology, literally meaning “the study of what is upon the people”, is derived from Greek epi, meaning ‘upon, among’; demos, meaning ‘people, district’; and logos, meaning ‘study, word, discourse’, suggesting that it applies only to human populations. However, the term is also widely used in studies of zoological populations (veterinary epidemiology), although the term “epizoology” is available, and it has also been applied to studies of plant populations (botanical or plant disease epidemiology).

When disease outbreaks or other threats emerge, epidemiologists are on the scene to investigate. Often called disease detectives, epidemiologists search for the cause of disease, identify people who are at risk, determine how to control or stop the spread, or prevent it from happening again. Physicians, veterinarians, scientists, and other health professionals often train to be disease detectives.

What do epidemiologists do?

Like investigators at the scene of a crime, disease detectives begin by looking for clues. They systematically gather information, asking questions such as:

* Who is sick?

* What are their symptoms?

* When did they get sick?

* Where could they have been exposed?

Using statistical analysis, epidemiologists study answers to these questions to find out how a particular health problem was introduced.

Disease detectives identify new diseases that have never been seen before, such as the 2019 novel coronavirus disease (COVID-19), Legionnaire’s disease, SARS (severe acute respiratory syndrome), and the organisms that cause them. They use what they learn during the investigation and make recommendations to control the spread or prevent a future occurrence.

Degree options for a career

* Bachelor’s degree – Most universities and colleges do not offer undergraduate programmes in epidemiology. Those who want to pursue epidemiology careers usually choose medicine or other health fields prior to graduate studies.

* Master’s degree – Epidemiologists are required to have at least a master’s degree from an accredited university or college. Most epidemiologists have a Master’s in Public Health (MPH) with a concentration on epidemiology, or a related field. While that is the most common degree, programmes that focus solely on epidemiology are becoming more popular. Most master’s programmes require students to complete a practicum or internship, which can last for up to one year. In addition to a master’s degree in epidemiology some programmes offer highly concentrated degrees for those pursuing particular career paths. Some areas of specialisation can include focus on cancer, cardiovascular disease, genetics, infectious disease, environmental causes and ageing.

* Doctoral degree – Some research epidemiologists may be required to hold a PhD or medical degree depending on the careers they choose. A doctoral degree provides graduates the skills and knowledge required to be at the top of their chosen field. The doctorate degree in epidemiology consists of one to three years of study and a doctoral dissertation. Those who earn a doctorate will find more opportunities available, including more in-depth research studies or options for teaching. Students in a doctoral programme can specialise in specific areas of epidemiology including cancer research or zoonotic infectious diseases.

Career pathways and salary

Those who pursue careers in epidemiology within public health work in many capacities including within universities and government organisations including the Ministry of Health, Centers for Disease Control in the US, the National Institute of Health in the UK, or the World Health Organization. The Bureau of Labor Statistics in the US states that epidemiologists earned an average of US$65,270 in 2012 with the top 10 per cent of them earning at least US$108,320.

Learn more about CDC’s disease detectives in the Epidemic Intelligence Service (EIS).