Heck, he didn't need to go all the way to Liberia to get sick.
In this same paper was an item about a CDC scientist who accidentally mixed a deadly form of bird flu virus in with a tamer strain and then kept quiet about it. The supposedly tamer stuff was sent to other labs where unsuspecting employees played with it for several months before discovering what they were messing with.
And right on the tail of that scary item followed another about the trial in a deadly contamination of a Georgia peanut plant. The owners allegedly covered up lab tests and knowingly shipped tainted products, knowing they tested positive for salmonella.
Woo hoo! Why go off to foreign countries to risk your life? Stay here at home and see what happens!