It is contagious under the right circumstances. Duncan could have easily passed it to to others in the apartment but they lucked out. His own cleanliness would play a role. Did he wash his hands after the bathroom? His "stepdaughter" took some precautions including disinfecting the apartment after he was taken to the hospital. She did that days before the moonsuit people came. Troh and others in the apartment would probably show symptoms by now if they got infected. It would be pretty hard to cover up since they had numerous media interviews and a visit from Jesse Jackson.
How would we know?
I have been looking and have not seen any status of the family in days.
Did I miss it?
.