Couple of comments on this one chaps and my apologies if what I say seems a bit obnoxious.
1) I notice that the first reaction of the U.S.Goverment was to disown one of their citizen's by preventing him from reentering the U.S.
2) There seems to be an assumption that someone with a fatal untreatable disease, who is being treated as a pharah, is going to care what happens to to the people around him. Common decency aside that is. Which could be arguably lacking in the standard of conduct exhibited towards the gentleman concerned. Being hounded does not exactly engender a feeling of helpfulness and co-operation.
3) If he had been quarantined by the Italian's he would have been humanely treated.
4) One of the major reason's why detaining people is so difficult in these cases is because such powers have been abused in the past. Being able to confine someone incommunicado on medical grounds is the sort of powers much beloved of Dictators. So such powers have to be exercised with great caution and be subject to serious independant judicial oversight.
5) Were the matter not so serious, I for one would applaud a man who goes to his bride. Come hell or high water.

Having said all that I have to say that if I had a fatal transmittable disease there is no way in hell that I would let anyone I love anywhere near me.