The U.S. Centers for Disease Control and Prevention estimates that there are 19-21 million cases of norovirus infections each year. Food is a vehicle for about 5.5 million cases, and the agency believes that improved food safety is an important part of reducing norovirus infections. This week, CDC issued a report on the latest statistics for norovirus disease and what the food service industry can do to prevent outbreaks from contaminated food. Between 2009 and 2012, there were 4,318 norovirus outbreaks reported to CDC’s National Outbreak Reporting System (NORS). Slightly more than 1,000 of them were linked to food, mostly from restaurants or catering facilities. Norovirus is the top cause of foodborne illness in the U.S. Of foodborne outbreaks in which a single cause was identified, 48 percent were caused by norovirus. Healthcare settings are the most common means of transmission for non-foodborne norovirus. While outbreaks on cruise ships may get most of the press, these incidents only account for about 1 percent of all reported outbreaks. Infected workers who touch ready-to-eat foods with their bare hands are usually the source of foodborne norovirus. The report notes that, while it is possible for norovirus to contaminate foods commonly eaten raw – for example, mollusks or fresh produce – most contamination happens during preparation. CDC’s key recommendations for avoiding contamination including proper hand-washing, use of utensils and single-use gloves when handling ready-to-eat foods, training and certifying kitchen managers, and requiring sick workers to stay at home until at least 48 hours after symptoms subside. That last one may be difficult for workers who don’t want to leave their co-workers understaffed or fear they might lose their job if they take sick days. The report notes that one in five restaurant workers have reported working at least once in the previous year while sick with vomiting or diarrhea. Aron Hall of CDC’s Division of Viral Disease suggests that businesses might consider measures to encourage sick workers to stay home “such as paid sick leave and a staffing plan that includes on-call workers.” As for proper hand-washing, the new report cites an observational study in restaurants which found that food workers only washed their hands in 27 percent of activities for which it’s recommended. When wearing gloves, they only washed their hands 16 percent of the time. “Although candidate norovirus vaccines are in development and show promise, behavioral interventions focused on food workers continue to be a primary means to prevent foodborne norovirus,” the report concludes.