A much used toilet seat harbours more germs than the china bowl part that the majority of people do not sit on. Putting paper on this part (extra safeguard), is preferable to the "warm" seat.
A girl that worked at a company I temped at once, (who was of ethnic origin - racial issues on AB are taboo - and, I hasten to add not what this comment is about), told me that she only washed one of her hands (religion), as one was used for personal hygiene and the other for eating.
I never dared to eat the biscuits she offered from the tin (shared in the office) after hearing that. She also told me (very friendly girl, got on really well), that because of their religion etc the females of her country, will hitch up their dress (again, I will not state the type of dress), and stand (in a crouching position), on the public toilet seats, as it is forbidden for them to sit down!