An Ebola particle is only around eighty nanometres wide and a thousand nanometres long. If it were the size of a piece of spaghetti, then a human hair would be about twelve feet in diameter and would resemble the trunk of a giant redwood tree.
Experiments suggest that if one particle of Ebola enters a person's bloodstream, it can cause a fatal infection. This may explain why many of the medical workers who came down with Ebola couldn't remember making any mistakes that might have exposed them.