Flesh-eating bacteria! Brain-eating amoebas! Worms living in your eyeball! These are not science fiction. They are science fact. Welcome to Shmoop's guide to infectious diseases.
An infectious disease is something that you can "catch." It means that something tiny got inside your body, probably without your permission, and made you sick. Bummer. Infectious diseases are responsible for 10-20 million deaths each year in the world. That means that approximately 1 out of 3 people who die on this planet today will die of an infectious disease.
Infectious pathogens (the things that can infect you) can be found EVERYWHERE. They are even on you and inside of you right now, and the only way to protect yourself is by reading this guide. Okay, okay that is not true, but we promise you some really cool (and creepy) information if you keep reading.
The most common causes of infectious diseases are viruses and bacteria. These two types of tiny troublemakers can cause diseases ranging from the common cold to the bubonic plague. Like a trending tweet they can spread from person to person and around the world very quickly.
You can also get infected by fungi and parasites. Did you know that some types of tiny worms can even burrow right through your skin and become permanent residents inside your gut? Talk about making your skin crawl.
With most infections, you won't even know that you have an unwanted houseguest until you start showing symptoms of a disease. Thanks to medical research, we have some treatments for many infectious diseases. One type of treatment is a vaccine which can prevent you from ever getting sick in the first place. If you do get sick, there are also a range of antibiotics, antivirals, and antifungals available too, depending on which type of disease you picked up. Unfortunately, however, though research has come a long way, there are still deadly diseases with no successful treatments at all.
In this chapter you will learn more about different types of infectious diseases and what bugs cause them. Pay attention, this information just might save your life someday (as a bonus, you'll learn big words like epidemiology).