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EPIDEMIOLOGY

Epidemiology is the science of public health. A boring definition of epidemiology might go something like this ...
"The study of the distribution and determinants of health related states in specified populations and the use of this study to manage and control health problems."


But actually it's more interesting than that. Epidemiologists are like detectives. They investigate disease, illness and infection. If there is an outbreak of a disease somewhere, as there has been with SARS recently it is there job to find out where it is coming from and how many people might be affected. They search for clues, they ask questions, they look for reasons and causes, they try to find answers and the information they find is used to help us all.

Epidemiology is concerned with the who, what, where, when and why questions of disease.
Who has the infection or disease?
Where do they live in the world and in relation to other people?
When is the disease happening?
What is the cause?
Why is it happening?

Whereas a doctor might be concerned with individual patients, epidemiologists study groups of people, sometimes whole populations. They gather data to find why a health problem is happening and how many people are affected by it or might be in the future. They look for patterns, try to see if what is happening is normal or suspicious. The information they find is then used to determine what, if any, action needs to be taken. They have different ways of working. They might conduct experiments over which they have control, for example in vaccine testing trials, where they can decide who is given vaccine and who is not and then compare the results. Or they might conduct observational studies in which they observe a health problem and event, finding who is affected and when and then analyse the information they collect to determine how and why people are affected.

Recently they will have been working to track the progress of the Avian Flu outbreak in parts of Asia. At the moment it can only be passed fron infected birds to humans but not from human to human. But there has been concern that the virus could mutate and be able to be passed from person to person. Every new outbreak will therefore be carefully monitored as it could lead to a worldwide pandemic.