Endemic, Epidemic, Pandemic - What's the difference?

in #health8 years ago (edited)

Everybody has heard and seen in movies the words endemic, epidemic, pandemic and so on; but what do they really mean? Which ones are the ones you should really care about? What is the difference between them? 

Hopefully we can clear up some misconceptions by giving you hard data and tools to explain to people that don’t know anything about the subject what is really going on.  

Let’s start with the basics, for something to be considered a biological hazards, because all those words are linked to biological agents and diseases linked to them.

You can’t use the word ‘pandemic’ when talking about a chemical agent for instance, although the word has been adopted worldwide as a slang term for something that is spreading very fast, be that an idea, product, fad and so on. The correct use of all three words is linked to biological agents and diseases linked to them, one can say that aids is an endemic disease for instance.  

So, what does endemic means?

A disease (or agent carrying such disease) that exists permanently in a particular population or region of our planet. For example, Malaria is endemic to several parts of Africa, and to my country, Brazil.  

The disease can be detected in several particular areas but not in a country overall, endemic diseases can be as small as a village or small group of people living by a lake for instance. If a disease has been endemic for long enough you can often observe resistances inside that particular population, one very interesting case happened in some parts of Africa where the locals developed the sickle cell gene making them very resistant to Malaria, therefore sickle cell gene can be considered a protective mutation. 

HIV can also be considered endemic in Africa, but it is not only endemic to that area, it is also epidemic.

Epidemic?

Yes, a disease can be both endemic and epidemic.

It means that the disease has spread further than its original endemic location, you can find such diseases in several districts or entire regions.

This means that an epidemic area is larger than an endemic area, and one epidemic can hold within it’s ‘borders’ several endemic locations.

But using our earlier example, HIV is not contained to one particular, although larger, region. HIV is everywhere, does that classify it only as an epidemic disease? No, HIV is actually one of the few diseases that have spread way more than it should, therefore HIV is considered a pandemic disease.

Pandemic

A pandemic disease is when you can observe the same disease throughout the world, in several continents, not necessarily all of them, but more than one.

This this of event tend to be devastating and very damaging to a population as a whole, be it human or otherwise, we can observe several examples of pandemic diseases right now, HIV as we mentioned already is in this category, but you can include the Influenza (flu) virus as well.

Here is a map of the H7N9 avian flu pandemic that happened in 2013.


Here is an interesting like of thinking that I would like you guys to respond in the comments, which disease is more likely to become epidemic a very lethal one (like Marburg) or a more tame disease (like Cytomegalovirus)? And please do explain why you think that.  

I hope this was entertaining to read and that it added something to your knowledge. 

Thank you very much for your time.

p.s.: Check some of my other articles!
The first time I was invited to make cocaine - https://steemit.com/drugs/@niann/the-first-time-i-was-invited-to-make-cocaine

Ebola Virus - A scientist's analysis - https://steemit.com/ebola/@niann/ebola-virus-a-scientist-s-analysis