Food Poisoning Incident Strikes Delfina, Won't Somebody Think of the Salad Greens?: SFist
How do noroviruses spread?
The norovirus enters through the mouth, multiplies in the body, and is passed in the highly infectious stool or vomit of an infected person. Food associated outbreaks have been linked to cold prepared, ready-to-eat foods (e.g., salads, coleslaw, sandwiches or desserts), fresh produce (vegetable, fruits and shellfish) and shellfish harvested in contaminated waters. Outbreaks have also been associated with drinking water and recreational water (e.g., swimming ponds and beaches) where persons may have ingested water contaminated with fecal matter from an infected person. Direct person-to-person contact or environmental contamination (e.g., exposure to areas where fecal accidents or vomiting has occurred) may also be a route of transmission.