Norovirus outbreak associated with ill food-service workers--Michigan, January-February 2006.

On January 30, 2006, the Barry-Eaton District Health Department (BEDHD) in Michigan was notified of gastrointestinal illness in several members of two dining parties after a meal at an Eaton County restaurant on January 28. An investigation was initiated by BEDHD to identify the source and agent of infection and to determine the scope of illness among patrons and employees of this national chain restaurant. Norovirus genogroup I (GI) was detected in stool specimens submitted by multiple patrons and employees. The investigation revealed that several food-service workers had been ill during January 19-February 3, 2006, and that a line cook had vomited in the restaurant on January 28, possibly increasing environmental contamination and transmission of virus. This report summarizes the findings of the outbreak investigation, which determined that at least 364 restaurant patrons had become ill. The findings underscore the need for 1) ongoing education of food-service workers regarding prevention of norovirus contamination and transmission; 2) enforcement of policies regarding ill and recently ill food-service workers; and 3) environmental decontamination with effective disinfectants to eliminate the presence of norovirus.