Peoples shopping habits have had a large effect on the flu reduction as well, this is a significant factor together with the supermarket separations etc. Online shopping taking off big time..
There are many vectors responsible for the reduction this being one.
Prior to the C factor the great British public were the great unwashed post public lavatory visit as I'm sure some will have noticed, this appears to have changed for the good too, so it seems it's never too late for a little childhood education in hygiene when faced with a life threatening disease.
