NJ, on this you are utterly wrong -- it is precisely because of volunteers like Pauline Cafferkey that we in the UK have little to fear now about Ebola. In the middle of 2014, when very few people cared about what was going on "over there", the result was an epidemic that was rapidly spiralling out of control. The volunteer effort is now leading, gradually, to this no longer being the case, and in two of the three countries the growth rate seems to be slowing.
Without so many volunteers, on the other hand, the epidemic was growing at an alarming and indeed exponential rate, with no sign of slowing. Thankfully in late 2014 the volunteer effort did step up, and the disease is on the verge of being contained (although the WHO continues to sound a note of caution, as well it should).
She has brought Ebola to the UK in only a technical sense, and there is only a negligible risk of the disease spreading here, so her actions haven't threatened our own lives -- only hers, and then only for the right reasons.