According to Royal Caribbean Cruise Line in order to help prevent illness travelers/general public should:

• Wash their hands- especially before eating or preparing food and after using the bathroom
• Avoid shaking hands during an outbreak
• Avoid preparing food for others for up to three days after falling ill
• Wash laundry that may be contaminated with stool or vomit

I’ve been on board cruise ships where they had staff present at dining room entrances and they made you sanitize your hands.

These days you can’t be too careful!