Diagnose and treat diseases affecting large populations.

What does an Epidemiologist do?

An epidemic is a contagious disease that spreads faster than expected throughout a population. Ebola and swine flu are recent examples of epidemics that grabbed headlines, while less dramatic ones include lung cancer, in connection with cigarettes, and heart disease in connection with fatty foods. Though different in the amount of time they take to act, all four are examples of diseases that an epidemiologist handles.

As an epidemiologist you diagnose disease just like a doctor does. But the difference is you diagnose disease as it occurs in entire populations. To do this, you don’t typically look at test results, since that would entail testing a lot of people. Instead you look at historical data. You use information like birth and death records, census data, and hospital records. The purpose of looking at all these data is to find connections between seemingly obscure things.

Say, for example, you’re dealing with an outbreak of flu that’s being spread through contaminated food. You observe a high rate of hospitalizations with that specific flu strain and then trace what the common symptoms are. If a large number of the patients ate food from one grocery store, then you can narrow your focus and find a way to stop the spread of the disease.

When you’re not dealing with an outbreak of disease, you use data to make connections about society’s other health problems. Epidemiologists carry out clinical trials to prove the safety of new medicines and, in general, search for ways to improve the population’s health.