This article is telling me that the majority of Americans are overestimating their exposure to the Ebola virus, while a few weeks ago I read an article in the s

This article is telling me that the majority of Americans are overestimating their exposure to the Ebola virus, while a few weeks ago I read an article in the same vein stating that Americans have a bad sense for how quickly viruses can spread. Is this a change based on the actual perception of Americans having changed or rather just differing opinions formed from differing source information? I am speaking in generalities of course, as I have not linked the other article and would not begin to know where to find it.