TUESDAY, Dec. 25 (HealthDay News) -- As you prepare your Christmas feast for your family, know that a new study finds that kitchen utensils such as knives and graters are potential sources of cross-contamination that can lead to foodborne illnesses.

Previous research has shown that meal preparation is a prime period for food contamination. It's known that the transfer of viruses and bacteria among hands, food and food-contact surfaces occurs easily at this point, but there has been little research on the role of kitchen utensils in this type of cross-contamination.

In this study, researchers examined the transfer of the hepatitis A virus and the norovirus (the leading cause of foodborne illness in the United States) between different fruits and vegetables and different knives or flat steel coarse graters. Tests were conducted with uncontaminated utensils on contaminated produce as well as with contaminated utensils on uncontaminated produce.

The results showed that more than half of the uncontaminated utensils became contaminated when used to prepare contaminated produce. Using a contaminated utensil on uncontaminated produce often led to contamination of the produce.

After an uncontaminated utensil was used on contaminated produce, the utensil could cross-contaminate up to seven more pieces of produce, said the study, published in the December issue of Food and Environmental Virology.

The findings show how easy it is for germs to transfer between produce and utensils, according to study author Qing Wang and her colleagues from the Center for Food Safety at the University of Georgia.

"Great emphasis on utensils as virus vehicles should be placed, and it is important to provide knowledge and training for food workers and consumers to limit virus spread," the researchers concluded in a journal news release.

More information

The U.S. Department of Agriculture's Food Safety and Inspection Service offers tips for safe food handling.