"I always use tissue to close and open the loo cubical door."
Someone going all Professor T here! 
I find all this hovering (nope, would bugger my already buggered knees, no good if you're pooing anyway, or san pro and bloody clots time......) VERY odd.........
I'm convinced it must be due to whatever public loo etiquette we absorbed as kids. I just sit and go, and so far I haven't caught anything nasty off a public loo seat. As regards touching, hands on door handles etc is far worse as regards transmission of nasties, if you really are worrying about that (I was just thinking advice given nowadays on cruise ships re appropriate hygiene, although could be hype. Do germs really persist for very long on hard metal or plastic surfaces? I seem to recall your chopping board has far more nasties than a toilet seat???).
So, since I'm not one, I'll blame the hoverers! Apart from one loo at my uni where the flush doesn't just sprinkle the seat, it spits about six inches, so you have to remember to skip away from the front before flushing............Oh, and only heard once in the UK (and it was americans) from women complaining how dirty toilets were in the UK since they didn't have disposable paper seat covers (The Turf Tavern in Oxford BTW)! A mad toilet in a Chicago airport I used after a long flight had an endless plastic strip that rolled out of one wall, around a U-shaped toilet seat, and back into the wall the other side. It was activated as you stood up or something, and watching it cheered me up no end! Actually, given the great advances we made when we first had public toilets for women, and given the unequal numbers in many uni buildings, and given the deplorable access for women in developing countries and the way they are used to keep women out of education -- we should feel bloody grateful, sit down properly, relax and enjoy the fact we don't have to crap in a field before sunrise miles away from home. Oh, and please try not to do this:
www.bbc.co.uk/news/uk-england-bristol-41167296..............