Might be a bit late but FWIW here's my input to this thread...........
Probably like most of you, when I am at home I know that all members of my family have been taught good hygeine practices so risk is therefore minimal.
But when I am in public places the whole game changes because there is potential to swap bacteria, viruses etc with so many people whose hygeine practices are completely unknown. It's a safe bet that at least some of them are likely to have hygeine practices that wouldn't make them welcome in my home though. I don't know if the person who touched the door handle or basin tap before me had some bug like Hep C or E. coli on his hands but I do know that, given the multitude of people who use public toilets, someone amongst them certainly would have.
A lot of bugs such as Flu viruses are primarily airborne so there's limited options for you to avoid them (even face masks have limitations) but there's a lot of others which are transmitted via direct contact with fomites (things like door handles, taps etc). The typical scenario is that an E. coli carrier touches door handle and deposits bugs; you touch handle after him/her and get the bugs on your hands; then it's pretty easy for the bugs to get to your mouth when you are eating etc.
So I suggest you should all be a bit circumspect about how you practice hygeine in public toilets, despite the fact that it may be contrary to what you generally regard as standard procedure. I now take the attitude that my "bits" are likely to have been maintained in far cleaner condition than a lot of other peoples' hands so I try to avoid touching anything that strangers have. For example I only use taps with on/off sensors or handles I can turn off with my elbow. I then dry my hands with my handkerchief. If I have to turn the tap handle I just won't use it. Do I instinctively want to wash my hands? Certainly! But not if it means swapping germs with that bloke who thinks "Hygeine" is just another name for a tall woman.