In light of the widespread, panicked reactions related to recent medical crises around the world, let's take a look at the psychology behind this phenomenon.
We often misperceive risk based on a variety of factors, including our exposure to or familiarity with the threat, how recently the threat has occurred, and our tendency to respond emotionally to events. When we misperceive risk, it becomes easy to search for evidence that confirms our deepest fears and ignore the evidence that suggests otherwise.
http://www.psychologytoday.com/blog/anxiety-files/201410/how-panic-spreads-fears-ebola