Don't touch that! It's dirty! While eating food off the floor is not a good, the filthiest places kids touch are actually not what you might expect, according to research at the University of Arizona. You think your bathroom's dirty? Playgrounds are the worst for germs that cause stomach upset, colds and flus - they've got bodily fluids on 44 per cent of the surfaces.
After that, the most likely sources of infection outside the home are public telephones, public toilet surfaces, pens on shop counters, chair armrests, elevator buttons, escalator handrails, shopping trolley handles and supermarket refrigerator handles.
You can't miss the joy kids get from elevator buttons, sitting in shopping trolleys and exploring the public toilet from top to bottom (sometimes literally). The solution: teach children to wash their hands. This means sudsing with soap for at least 10 seconds, then rinsing and drying with a clean paper towel or hand dryer. There are 200 times more bacteria on a cutting board than on a toilet seat.
Kitchen sponges and dish rags have 6,000 bacteria per sq cm. Next come the kitchen and bathroom sinks, kitchen tap handles and the refrigerator door. At home, use a disinfectant that kills both bacteria and viruses to protect children against illness. And don't forget hand-washing.
The jury is still out on whether children thrive better in dirt or in scrupulous cleanliness - tell me it's dirt, and I'll be happy. There is a theory that asthma is on the increase because children aren't getting enough garden dirt on their hands but elevated levels of endotoxin in house dust are associated with an increased risk of wheezing in certain infants during the first year of life, according to the American Journal of Respiratory and Critical Care Medicine.
And, to really confuse you, children raised in homes with very high levels of cat allergen have a reduced risk of sensitisation and asthma compared with children who have a moderate exposure to cat allergens, according to a report in the Lancet. So there's good dirt and bad dirt . . . problem is, which is which?