sft42 has a point in that we tend to disinfect our homes now rather than scrubbing them. This, according to my friendly occy health nurse, kills off the vulnerable bugs that would have tested our immune systems without making us ill and leaves the nastier ones, giving us nastier colds, flu etc. She is a great proponent of a bit of healthy dirt, plus soap and water handwashing and hot water and soap scrubbing to clean to protect us against the nasties. NOBA, the habits of trapping coughs and sneezes in a handkerchief seems to be dying out, plus the darling habit of spitting in public appears to be in rennaissance, so we tend to be more generous in sharing our own personal infections in public. Also, I live in the south of england, and its my perception that this spate of warm damp winters that we have had recently has meant that like the garden pests, the bugs have not been reduced by nature. I also think that we tend more to "struggle on" with colds flu etcetera, both sharing the bugs around and putting more stress on our bodies in fighting them off. Lots of alsos there and I sound like my own grandmother!!