What is an epidemiologist and what do they do?

Epidemiologists have been at the forefront of the public health response to Covid-19. But what exactly does their work involve?   

Woman with face mask and white coat

What is epidemiology?

Simply put, epidemiology is the study of health and disease. Sometimes called ‘disease detectives’,  epidemiologists collect information about disease and outbreaks and analyse data to find out where, when and to who a disease is spreading. 

Crucially, epidemiologists try to make sense of disease in populations, rather than just in individuals. In fact, the word ‘epidemiology’, derived from Greek, translates to "the study of what is upon the people".  

But which diseases do epidemiologists study? There are various branches of epidemiology, which cover not only infectious diseases like Covid-19 or polio but also chronic diseases like heart disease and cancer. 

Some epidemiologists may also seek to understand the impacts of behavioural factors like smoking and alcohol consumption or external factors like exposure to smoke or pollution in a person’s environment. 

The information epidemiologists gather is then often used to influence public health policy—to help guide governments to keep their populations healthy—and to develop preventative measures like vaccines. 

What does an epidemiologist do?

Depending on the type of epidemiologist you become, you may be involved in:  

  • Clinical trial design and analysis 
  • Population studies or surveys 
  • Vaccine and drug development 
  • Public health policy development 
  • Lecturing, teaching and academia

As an epidemiologist, you may find work in a: 

  • Hospital or healthcare setting
  • Government or global health agency 
  • University 
  • Research institute

Common questions about epidemiology

Is an epidemiologist a doctor? 

Not necessarily. While they study disease, epidemiologists aren’t responsible for treating it in an individual. Instead, they play a more high-level role by using their research to inform public health policy. 

Why is epidemiology important to public health? 

The information gathered by epidemiologists is crucial for influencing public health practice and interventions. For example, epidemiologists have played a vital role in understanding the transmission of Covid-19 and advising governments around the world on how to prevent its spread. 

What are the different types of epidemiologists?

There are many different types of epidemiology that you can choose to specialise in. For example:

  • Infectious disease epidemiologist – working in a lab or out in the field, you’ll study the impacts of communicable diseases like Covid-19 or influenza and help discover how an outbreak has occurred.
  • Molecular epidemiologist – combining molecular biology with epidemiology, you’ll study the relationship between cells, proteins and genes to understand causes of and risk factors for disease. 
  • Field epidemiologist – likely working for a government or global health agency, like the World Health Organisation, you’ll travel to sites with disease outbreaks to understand what’s happening on the ground and help communities respond. 
  • Medical epidemiologist – combining your background in medicine, you’ll monitor disease outbreaks, study clinical pathology and research potential cures for disease. 
  • Pharmaceutical epidemiologist – most likely working in a lab, you’ll help understand the impacts of drugs on populations.
  • Veterinary epidemiologist – also called an epizootiologist or epizoologist, this specialised type of epidemiologist studies the spread of disease in animals. You’ll first need veterinary qualifications to pursue this branch of epidemiology. 

Epidemiologist qualifications and how to become an epidemiologist

To become an epidemiologist, you need to study at both the undergraduate and postgraduate level. 

Because most Australian universities don’t offer specific undergraduate epidemiology courses, you’ll need to first undertake a broader health or medicine course like a bachelor degree in public health, medicine or biostatistics.   

You can then specialise in epidemiology at the postgraduate level so you can qualify for epidemiology roles. Many epidemiologists also complete study at the doctoral level to build their level of expertise and qualify for senior careers in public health or academia.

Where to study epidemiology?

If you’re interested in epidemiology, we recommend studying with a university that boasts a solid reputation in health and medicine. QS World University Rankings and Times Higher Education University Rankings allow you to see which unis fare well in different study areas.

Open Universities Australia also allows you to compare the cost and content of courses in the field of health—a crucial step in ensuring you’re studying towards an epidemiology career with the university that best suits your needs. It’s never been easier to weigh up your options, all in one place. 

Our friendly student advisors can also help you weigh up which university is the right fit for you. Why not book a free phone consultation today?  

Epidemiologist salary

According to Payscale at the time of publishing, the average national salary for an epidemiologist in Australia is $95,000. However, the exact salary you can expect will vary depending on your speciality, role, level of experience and qualifications. 


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