It has become a ritual for some parents: Before every snack and after every cough or sneeze, mom whips out a handy travel-sized bottle of hand sanitizer to clean her child's hands. And if the bottle runs out, no worries: schools, offices and public buildings are festooned with wall-mounted dispensers of the germ-killing gel.
Do constant applications of hand sanitizer promote better health? In a recent study at the University of Virginia, test subjects were instructed to apply sanitizer to their hands every three hours, while a control group did not take special precautions. The study showed no statistically significant difference in the number of cold or flu viruses each group contracted. Researchers believe the viruses that cause the cold and flu, including the H1N1 virus, are more commonly communicated through the air than through physical contact with an infected surface.
But don't throw out the sanitizer just yet.
"We know that good hand hygiene decreases the transmission of infection," says Dr. Jorge Parada, medical director of the Infection Prevention and Control Program at Loyola University Medical Center.
"You can pick up almost any kind of illness through contact. If someone coughs into their hand and then shakes your hand, and after that you scratch your nose, you can pick up that virus."
Parada urges frequent hand washing as well as "basic cough etiquette," coughing into the elbow or sleeve rather than the hand. Since children today often eat outside the home, he recommends parents carry a bottle of alcohol-based sanitizer for times when soap and water aren't available.
The goal, he explains, is simply to make clean hands a habit, not to eliminate all germs from the child's environment.
"We have about a thousand times more nonhuman cells living on us than human cells," he says. Most of those resident bacteria are harmless, and some are even beneficial, helping to regulate the skin's inflammatory response to cuts or scrapes.
"What you want to do is get rid of the unwanted microbes," Parada says. "Some moms worry that they're not getting operating room-level sterility in the care of their children, and they shouldn't worry. They should just teach kids to wash their hands."