Hand washing is only part of the problem. You could scrub everyone down as they boarded the ship and still have an outbreak that could affect half the ship. The virus doesn't attack the instant you get it--people come in from all over in planes, get into vans, buses, cabs, etc and pick up all kinds of things that the people who just vacated those planes,vans buses, cabs, etc left behind.
A far as signing a paper saying you are or are not sick, you could be feeling fine when you boarded and sign that , yes, you are well--then a couple days later be very ill. So, signing the form re/ sick / not sick is basically a waste of time.
You can do so much but people have to realize that a ship is basically an enclosed environment on which there are normally 2500 , 3000 or more people from all walks of life thrown together and if someone gets something contagious, it's likely to spread.
I wash my hands thoroughly, not only on a cruise but at home, use Purell all the time and hope for the best.
Regarding using the hand sanitizers prior to going into the dining room, I think they are a great thing but that isn't going to keep you from getting something. When you order a glass of wine with your dinner, how many people have handled that glass after you came in and washed you hands with sanitizer at the door? How many people have handled the salt / pepper shakers prior to you? How many people have handled the menu prior to you--how many have washed their hands, used sanitizer and then coughed or sneezed on the table, menu, salt / pepper shakers, etc?
Yes, I know all about people going through the buffet lines with no manners at all--I've seen people reach and get food with their hands instead of the tongs--seen people get pieces of food, actually put it in their mouths and then lick their fingers and then handle the tongs.
While we're at it, what about the casino? How many hands have been on the slot machines, where all have those hands been,etc before you come along behind them?
It's not just a matter of washimg--- people can help by being clean but as has been mentioned, if there were a way to control their cleanliness or lack thereof in the publlic places, how are you going to control how clean / dirty they are in their cabin?
Then too, what all do they pick up ashore and bring back to the ship that gets spread around?
If you keep going the chain would be endless as to how and why people get sick--main reason that we hear about it is as I first mentioned, it's in an enclosed area --a ship-- If you go to the store, handle the carts, handle food stuffs that others have handled and put back, take a reciept from a clerk that has handled checks and money all day how many germs of different types do you come in contact with--if you get sick then a coupe of days later, most people would never connect it with the store. Same thing at the gas punp. Do you or anyone that you know of wipe down the gas pump handle prior to using it to gas up the car?
Anything that happens on a ship is instant headlines--
If you cruise, you take a chance-- if people are unwilling to take the chance, I can understand it and those should at home where they think it's safe-- safe only in their mind though!
You are likely to get sick anywhere-- it's not news if 200 people in Peoria, Ill. get the back door trots and a tummy ache , although they may have caught it at the store, you just never hear about it as once they leave the store, they spread out all ove the area but if it were on a ship, of course it would be meat for the media. I don't have a solution to the problem and it's pretty plain no one else does, as it's being going on for years and will likely continue.
Do the best you can, use a napkin to handle the tongs with, but don't use it as your regular napkin--cleanse you hands after getting your food and handling the salt / pepper shakers and dig in and hope for the best !