I just came off of the Crown on Saturday. Luckily, hub and I did not get sick but I did hear from my waiter that 200 passengers and a few crew did get sick. The captain kept us well informed about the situation and we could see by the phone calls and alerts at the Guest Relations Desk area that they were inundated by the numbers. The captain said that there were two docs and ???4 nurses helping, working around the clock, and asking those who were not as sick as others to be patient and that they would get to them.
One woman passed out in the dining room, another person got sick in the casino. The casino was briefly closed. One elevator was taken out of service.
The ship was at code yellow early in the cruise, and then everything was fine. At @3 am Friday, all heck broke loose, I understand. You actually saw them washing down the walls in the photo gallery and Sabbatino's (Italian specialty restaurant) started their intensive cleaning @12 midnight Sat (when we left it). Our waiter said that the two specialty restaurants were going to be closed Saturday in order for the staff to help out participate in the cleaning of the ship. (The ship did not leave until 10:30 pm Sat anyway, so that was a mute point, but no one knew it then on Friday evening.)
They had hand sanitizers at the entrance of the buffet but people will be people and some just went right through without making use of it.
We ate breakfast at the Int'l Cafe, lunch was pizza (in both venues, the food was handed to you by the staff and there was not the mass of humanity surrounding you as there was in the main buffets), and dinner was Sabbatino's nightly (again, not as large a venue as MDR).
On Friday, I happened to pass buffet and they were handing out the dishes, salt/pepper packets, and you would go to the food which you wanted and pointed, and the staff served you. Unfortunately, they should have continued this when it was code yellow and perhaps the effects would have been less.
The captain told everyone to use their own bathrooms and I walked around with antiseptic wipes and Purell bottles in my pocket. We used tissues to push the elevator buttons, did not use the handrails, and did not shake hands. When we saw sick people, we got off the elevator or wherever we were and went the opposite direction.
At no time was there panic or disruption on board. Princess handled this in a calm and professional manner. I give the captain and crew credit for conducting it in such a fashion.