ATLANTA – Most outbreaks of norovirus occur in foodservice settings, and 70 percent of infected workers cause 70 percent of the outbreaks, the Atlanta-based Centers for Disease Control and Prevention reported in its latest Vital Signs report.

The CDC analyzed norovirus outbreak data from state, local and territorial health departments from 2009 to 2012. During that period, health departments reported 1,008 norovirus outbreaks from contaminated foods. Most of the outbreaks occurred in restaurants and catering or banquet facilities, according to CDC.

“Norovirus outbreaks from contaminated food in restaurants are far too common,” said CDC Director Tom Frieden, MD., MPH. “All who prepare food, especially the food service industry, can do more to create a work environment that promotes food safety and ensures that workers adhere to food safety laws and regulations that are already in place.”

In response to the CDC report, the National Restaurant Association agreed with some of the agency's recommendations for preventing norovirus, but took issue with some aspects of the study.

“We agree with many of CDC’s suggestions as to what can be done. However, we believe that some of the language is misleading and that norovirus is not common in the industry, as the report claims," said Scott DeFife, executive vice president for Policy and Government Affairs. "The report shows that the overwhelming majority of norovirus outbreaks during the studied time period were non-foodborne. Restaurants serve 130 million meals each day, and while any instance is serious, there are very few instances of norovirus contamination.”

Factors contributing to food contamination were reported in 520 of the outbreaks. CDC said an infected food worker was implicated in 364 of those outbreaks with 196 outbreaks involving food workers touching ready-to-eat foods with their bare hands. CDC found that 1 in 5 food service workers reported working at least once in the previous year while sick with vomiting or diarrhea. Workers cited fear of job loss and not wanting to leave coworkers short-staffed as significant factors in their decision to work while sick.

“It is vital that food service workers stay home if they are sick; otherwise, they risk contaminating food that many people will eat,” said Aron Hall, DVM, MSPH, of CDC’s Division of Viral Diseases. “Businesses can consider using measures that would encourage sick workers to stay home, such as paid sick leave and a staffing plan that includes on-call workers.”

DeFife said the NRA and foodservice operators take food safety very seriously, and that there is no greater priority than food safety and the well-being of customers and food industry employees.

“In its report, the CDC notes the demonstrated success of training and certification of kitchen managers in preventing norovirus outbreaks, which we support and encourage,” DeFife said. “Through the National Restaurant Association’s ServSafe food preparation training program, over 5.6 million foodservice workers across the US have been trained in the safe handling and serving of food. The program provides specific recommendations on ways to prevent norovirus, including proper hand washing and exclusion of sick employees.”

CDC also found that in 324 outbreaks attributed to a specific food item, 90 percent of the food items were contaminated during final preparation and 75 percent were foods eaten raw. The foods most commonly implicated included leafy vegetables, fruits, and mollusks such as oysters.