Talk Like an Epidemiologist

This might just be enough to make you lose your appetite.

There you are, home early, and you decide to throw together a little dinner, flop onto the couch, and watch some TV. You happen to flip on the news and hear the anchor report:

There’s lot of medical news tonight, an outbreak of Ebola virus in West Africa, and here in the U.S. and across the globe, the flu virus has hit pandemic levels.” 

None of it sounds good. But before you grab a storage container and put the dinner in the refrigerator, let’s understand what it all means to epidemiologists, the folks who study diseases, because those terms have very different meanings. 

First, consider the town you live in. It has a specific population and each year, a certain percentage of that population gets the flu.  If the flu strikes this year, and the percentage of the population that gets sick is what scientists expect, they say the flu is ENDEMIC to the population. People are getting sick, but the illness is at a level that was expected. 

Now let’s say it’s an above average flu season, and that more people than normal are getting sick with the flu. Scientists would say there is an EPIDEMIC, because more people than expected are getting sick, but the virus is still isolated to the original population (your hometown). 

In a sense, the term OUTBREAK carries the same definition, but refers to a more limited geographic area. A disease outbreak means the illness is happening in greater numbers than what was expected in a community, or a geographical region or in a season. An outbreak may occur in one community or even extend to several countries, lasting from days to years or anything in between. 

Sometimes, after an outbreak, a disease becomes a PANDEMIC. That means the illness is now infecting multiple countries or even globally. You could say that every year the flu becomes a pandemic because it strikes people on several continents. 

With a better understanding of how bad the viruses are spreading, you can now go ahead and eat your dinner.  But be sure to wash your hands before you do. The Centers for Disease Control say that’s still the best way to stop illnesses from spreading. 

— Frank Graff 

Frank Graff is a producer/reporter with UNC-TV, focusing on North Carolina Science Now, a weekly science series that airs Wednesdays, beginning in August 2013, as part of North Carolina Now on UNC-TV. In addition to producing these special segments, Frank will provide additional information related to his stories through this North Carolina Science Now Reporter's Blog!  


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