I'm with you OP. I don't have OCD, but definitely feel very differently about norovirus than colds, chicken pox, even Covid. Unlike a PP, even when the pandemic started, I was of the view that I'd rather take my chances with it than get norovirus again!
I think one reason is that maybe emetophobes are more prone to getting sick bugs than those who treat them like any other illness? Because we know how hideous they are and they're not that uncommon?
I've also heard the blood type theory and I am also unfortunately type O. I had numerous sick bugs as a child and then luckily had a hiatus until I had my own children (interspersed with two bouts of food poisoning from restaurants and one contracted in Asia though I don't fear food poisoning in the same way as I have more control over that I guess!)
My biggest fear is contracting sick bugs from my DD as that has been my source for the past five years and sadly she has inherited my sick-proneness genes... For the four years before the first lockdown, she (and subsequently I) had one sick bug a year... Then because of social distancing, a break of nearly two years.. But then she seemed to make up for it by having five in the space of five months(!) I was super-obsessive with bleach, face masks etc though and touch wood managed to avoid... But still terrified despite this 'exposure'!
Touch wood, my DS does not seem to have the sick-gene and has never been sick through illness.
I think my biggest fear is it going through all four of us and having to deal with that..
So definitely in awe (and envy) of those who never seem to get sick bugs... I'm not sure I believe the stat of only ever having 5 in a lifetime.. Definitely not the case here!