Wash your hands every hour or so. There are bathrooms everywhere. Be compulsive, obsessive about washing your hands. Just do it. In ten months, I never got sick. Virtually EVERY other person (in the crew) got sick sometime.
No, I have not had my genes tested.
This is my 100% non-medically based opinion based upon what I saw when “a lot of folks got sick” while I was on the boat. I believe that what is termed “norovirus” (in the context of “a bunch of folks got sick on the boat”) is so termed because the symptoms are pretty much identical to an actual stomach flu. But it is my belief that the cause is bacterial in most cases, not viral. (Thus “genes” considerations probably do not really apply) And I could be completely wrong. But when you have 2500-4000 people using a handrail that you are really supposed to use descending a grandiose stairway (they DO tell you that) or around the perimeter(s) of 8-9 observation decks, your hands are ultimately and firmly clasped around many of those 2500-4000 people which includes WHEREVER their hands have been. Nuff said. Additionally, most cruises are, as I said, Caribbean affairs and the ports are often Boston and NY or Florida (= NY, really) and people get colds and flu there in the wintertime and do not cancel their trips and think they will recover nicely in the hot sun. So plenty of folks get on the ships really fairly sick with colds/flu, on the front or trailing ends of such illnesses and they blow their noses or sneeze in their hands and then use the handrails. Again, nuff said.
When “a lot of people got sick” the bleach and alcohol crews were dispatched in strong numbers and they aggressively scrubbed the handrails, all of them. Keep in mind that each and every thing the cruise lines do, they have done a billion times and short of running aground, they are most fearful of these “noro” outbreaks because they generate massive bad will. Yet at the same time, it isn’t exactly public-friendly for them to have big signs saying “wash your hands” every 50 feet when you think about the implications. The alcohol dispensers *DO* come out and are placed outside all the restaurants whenever there’s a noro outbreak. So there you go.
So, just observing all that and knowing that most colds are transmitted by (your) hands to (your) eyes, it remains my reco that aboard such a ship, you just become flaming obsessive about washing your hands a lot, a whole heck of a lot, and become very mindful of any time you touch something that others touch and REALLY REALLY try not to rub your eyes. If you take those simple steps, you don’t really have to think about anything.
A gene to not get the Norovirus?
That is awesome, and a new one for me.
My adopted daughter just has the gene that prevents her from sitting quietly.