As the weather turns colder and leaves begin to change colors, it's a sure sign of a dreaded annual occurrence: the return of cold and flu season. But a Purdue University public health expert says one simple tip can help prevent a lot of illness.

The most important thing that can be done to prevent colds and flu is the practice of good handwashing skills," says Pamela Aaltonen, associate professor and director of engagement in the School of Nursing. "As the temperatures outside drop and we all start spending more time in enclosed spaces, we start sharing the same organisms, which live on surfaces such as doorknobs and keyboards. That's why it is so crucial to wash these organisms off to prevent their spread."

Aaltonen says studies have shown that 40 percent to 60 percent of people don't wash their hands after using the restroom. And those who do wash their hands often don't know the proper technique.

"Most people who do wash their hands do so much too quickly," she says. "In order to be effective, hands should be washed with soap from 20 to 25 seconds. The three keys are soap, friction and water.

"If we could get the world to embrace handwashing, we would have much less illness."

She says hands should be washed after going to restroom; before preparing and eating food; after helping a child to use the bathroom; after changing a diaper; after blowing your nose, coughing or sneezing into your hands; after handling animals or animal waste; and before carrying out first aid for an open cut or wound.

Aaltonen says waterless hand sanitizers are an acceptable substitute if traditional handwashing is not an option. She says one reason those products are effective is that people tend to use a lot of friction when they apply them and the friction kills more germs.

In addition to handwashing, Aaltonen says eating right, getting enough sleep and exercising help bolster the immune system and fight sickness.

"Doing these things boosts what we call inherent resistance," she says. "For instance, we see a lot more illness among college students around midterms and finals because they have been skimping on sleep and not eating right."

She says it also is important to stay home from work or school if you do feel under the weather to avoid carrying germs into a larger population.

Aaltonen says colds and the flu usually go away on their own within a week, but medical attention should be sought if the person has an existing chronic illness or if new, unexpected symptoms appear. Also, older people should take special care because pneumonia can develop after a bout with flu. People in these groups should see their health care provider to get a pneumonia vaccine and an annual flu shot.

Source: Purdue University