Assessment of Food Safety Regulations for Prevention of Norovirus Outbreaks

BACKGROUND:  Noroviruses are the leading cause of foodborne illness in the United States. Foodborne norovirus outbreaks are commonly associated with contamination of food during preparation by an infected food service worker, often involving bare-hand contact with ready-to-eat (RTE) foods or working while ill. The United States Food and Drug Administration’s Food Code provides model food safety regulations to prevent transmission of foodborne illness in food service facilities; however, adoption of specific provisions is at the discretion of state and local governments.

METHODS:  We analyzed the food safety regulations of all 50 states, the District of Columbia, and Puerto Rico to describe differences in adoption of norovirus-related food safety provisions between jurisdictions and the 2013 version of the Food Code. We then assessed potential correlations between adoption of these regulations and characteristics of foodborne norovirus outbreaks reported to the National Outbreak Reporting System during 2009–2013. Key areas assessed from regulations were hand-washing procedures, prohibiting bare-hand contact with RTE foods, management of ill workers, having a contamination event response plan, and requiring a certified food protection manager (CFPM).

RESULTS:  Of the regulations assessed, provisions requiring hand-washing and prohibiting bare-hand contact with RTE foods were most widely adopted. 47 of 52 (90%) jurisdictions require hand-washing and 49 (94%) prohibit bare-hand contact with RTE food. In contrast, 22 (42%) jurisdictions require a CFPM and 7 jurisdictions (13%) require a response plan for contamination events, such as vomiting. Nine states (17%) do not provide specific management criteria for ill workers. Controlling for outbreak reporting rate, jurisdictions requiring exclusion or restriction for ill food workers reported 32% fewer foodborne norovirus outbreaks, as a percentage of all reported norovirus outbreaks (p=0.001). Adoption of provisions requiring hand-washing, CFPM, and a contamination event response plan, and prohibiting bare-hand contact with RTE foods were independently associated with fewer foodborne norovirus outbreaks, as a percentage of all reported norovirus outbreaks, though results were not statistically significant.  

CONCLUSIONS:  Overall, most jurisdictions have adopted some form of the recommended provisions to reduce foodborne norovirus transmission, although there is variation in the adoption of specific regulations. We identified some possible associations between adoption of food safety provisions and reporting of outbreaks, although these observations are likely confounded by compliance and reporting practices. Focus on enactment and improved compliance with recommended provisions may decrease incidence of foodborne transmission of norovirus.