I was on the 1/18/05 Sun Princess sailing and can speak about the GI virus outbreak.
I spoke with one of the Sun's nurses, who confirmed that the medical staff had traced the GI infection to a passenger who admitted that he had been sick the day before sailing and had falsified the required affadavit where each passenger must answer whether they have been ill or not. He said he didn't want to miss the cruise, so he answered "no" about being sick within the past 48 hours. As a result, his infection spread to 89 passengers, two of whom were our dining room tablemates, and 5 crew members.
I have sailed 22 cruises with Princess, and this was the first time that such an outbreak occurred. At the same time, there was an outbreak on a Royal Caribbean ship, docked next to the Sun Princess in Fort Lauderdale. It can happen anywhere, anytime...be it a land restaurant, a school, day care center, whatever.
It happened, and Princess took care of it immediately by notifying all passengers and waiving all medical charges to any passenger who needed medical treatment for their symptoms. Yes, there was some slowness at times in the dining areas while each passenger used hand sanitizer before entering, but it was not a big deal and just a minor inconvenience.
I was pleased and impressed with Princess's response and efforts to curtail any spread. Only 89 passengers out of 2,100, after being discovered within the first 24 hrs of the cruise....that's not bad, in my opinion. It could have been much worse