COLUMBUS, Ohio—Restaurant dishes and silverware may be an overlooked place where people can catch stomach viruses, according to a new study published today on the PLOS ONE website. While the current industry guidelines for cleaning dishware used in public settings are effective at neutralizing bacteria, researchers at the Ohio State University found that they appear to fall short of eliminating norovirus.
Norovirus is the leading cause of epidemic gastroenteritis and the major cause of foodborne illness worldwide, responsible for at least 50 percent of all gastroenteritis outbreaks in the United States.
“We know that when public food establishments follow the cleaning protocols, they do a very good job at getting rid of bacteria," said Melvin Pascall, associate professor in the Department of Food Science and Technology at Ohio State. “Now we can see that the protocols are less effective at removing and killing viruses—and this may help explain why there are still so many illnesses caused by cross-contaminated food."
Supported by a grant from the Ohio State Center for Clinical and Translational Science, Pascall and Jianrong Li, assistant professor of virology at Ohio State, led a team of virologists and public health experts to test the ability of the norovirus and common bacteria to make it through a variety of “real life" food service cleaning scenarios that included manual and mechanical washing.
To carry out the experiment, the research team infused cream cheese and reduced fat milk - two foods that are known for being difficult to clean off - with murine norovirus (MNV-1), Escherichia coli (E. coli K-12) or Listeria innocua (L. innocua). The scientists then applied the dairy products to stainless steel utensils, ceramic plates and glassware, and put the tableware through a variety of chlorine and quaternary ammonium compound (QAC)-based sanitary protocols delivered via a commercial dishwasher or hand washing.