oh please... then why not do a full investigation to find out whether or not she caught this in the hospital or came in with it? that's the least they could do... saying that "perhaps" she already had the disease is not good enough... she ought to be able to find out as much as she can...
People DO get gangrene outside of hospitals. You imply you know how she got it and it was at the hospital, when that is simply not known at this time. There is/will be a full investigation in the hospital. It is required by law.