The Truth About Germs

Myths -- Busted!

The Famous Five-Second Rule

If something hits the floor for less than five seconds, can you assume it's not contaminated and give it right back to a child? Not usually. In one small University of Illinois study, researchers tested wooden floors in high-traffic areas around the university and found that there wasn't much bacteria to contaminate dry-food items. Many tile and wooden floors are dry and therefore don't support bacterial growth, says lead author Meredith Agle, PhD. But when E. coli was put on tiles, she found that the food was contaminated within seconds. And keep in mind that restroom floors can be germ-ridden areas, says Charles Gerba, PhD, of the University of Arizona, who conducted a study of more than 50 restrooms. Remember, too, that the University of Illinois study didn't test carpeted floors, a surface that might contaminate items with bacteria instantly, says Agle. She also notes that her study didn't look at how quickly a dropped item might be contaminated with viruses, nor did it consider nonfood items, such as pacifiers. "I think you are less likely to transfer bacteria on dry food or toys than on drool-laden pacifiers," says Agle.

But there will be times when washing just isn't possible. "I didn't use the five-second rule, but I did use my 'crawling rule,'" says Christina Greene, of Chatham, New Jersey. She meticulously washed everything before her son, Christian, who turned 1 last November, began crawling. "But once he was mobile, I'd turn around and find him chewing on our shoes," she says. "How much worse is it if he drops a toy on the floor and then puts that in his mouth?"

Donald Schiff, MD, professor emeritus of pediatrics at the University of Colorado School of Medicine, in Denver, agrees: "If you're hyper-strict about cleaning, you'd have to keep a child off the floor and also keep everything out of his mouth. There has to be some sense of humor and practicality about this."

Are You a Germ Worrywart?

The Down and Dirty Playground Equipment: The greatest number of bodily fluids (urine, saliva, and mucus) are found on the highly used monkey bars, swings, and slide, says microbiologist Charles Gerba, PhD.

Public Toilets: It's unlikely you'll catch an illness from using a public bathroom, says infectious disease expert Thomas Sandora, MD. Wash your hands to be sure.

Unwashed Fruit: Produce can carry E. coli, but when you rinse it, you reduce the number of bacteria tenfold, says microbiologist Meredith Agle, PhD.

Toys at Daycare: They are generally wiped clean, says Gerba.

Paper Money or Library Books: Dry items like these are not usually germ-ridden even though they're handled by lots of people, says Gerba.

Do We Need Some Germs?

Whether or not exposure to some germs is actually good for your immune system is a medical controversy. Asthma is a case in point. "Some people believe that if you're not exposed to infections at a young age, you have a higher chance of getting asthma down the road," notes Thomas Sandora, MD, of Children's Hospital Boston. But the research isn't clear on this, he says.

The use of antibacterial soap has also sparked debate. It has come under fire for possibly causing resistance to antibiotics, but the FDA said last October that there is no evidence of this in people. "However, there is laboratory evidence of resistance," says Stuart Levy, MD, a professor at Tufts University School of Medicine, in Boston, and author of The Antibiotic Paradox (Perseus Books, 2002). "Scientists need to examine this issue over a longer period of time." Either way, the main problem with antibacterial soaps is that they don't do a better job of taking germs off your hands than regular soaps, says Alastair J.J. Wood, MD, chairman of the FDA's Nonprescription Drugs Advisory Committee.

Janice Perrone, a mother of two, lives in Chatham, New Jersey.

Originally published in American Baby magazine, February 2006.

The information on this Web site is designed for educational purposes only. It is not intended to be a substitute for informed medical advice or care. You should not use this information to diagnose or treat any health problems or illnesses without consulting your pediatrician or family doctor. Please consult a doctor with any questions or concerns you might have regarding your or your child's condition.