The problem is that the passengers leave the ship but the crew is left behind, still spreading the virus amoungst themselves. This causes a never-ending cycle of illness and contamination. It doesn't matter how many hours are spent cleaning the ship as long as the crew is still sick.
The Ryndam had Norwalk in Alaska last summer. The cruises ran for about 3 weeks before HAL finally cancelled a cruise, let the crew get well, and had the ship professionally cleaned. That was the end of the virus.
The Amsterdam sailed for 4 weeks before HAL *woke up* and cancelled a cruise. She is sitting now, the crew is finally going to get it out of their system, and then the ship will be professionally cleaned. I'm sure that will end the virus, just as it did on the Ryndam.
I believe Disney should cancel one cruise, just as HAL did. Otherwise, that virus will be running rampant. I am really worried about the children because their immune systems tend to be more fragile than that of adults.