Aaron Kinney reports that the San Mateo County health officials announced Friday that norovirus was behind an outbreak of acute gastrointestinal illness at the upscale Hotel Sofitel in Redwood Shores.

Lab analysis of samples taken from some of the people who were sickened confirmed the highly contagious virus was to blame. At least 60 hotel guests and employees reported falling ill with symptoms including vomiting and diarrhea beginning Oct. 26, county health spokeswoman Robyn Thaw said.

Thaw said the hotel told county health investigators that guests at three separate special events became sick.

The outbreak began at the conclusion of the NAACP’s annual state convention. Attendees said several dozen people became sick on the morning of Oct. 26, a little more than 12 hours after a banquet dinner where roughly 300 people dined on salmon and salad. Twelve people were taken by ambulance to hospitals.

Norovirus is spread through contact with the vomit or feces of an infected person. Food service workers can spread the virus by not properly washing their hands before touching food.

People typically come down with norovirus symptoms between 12 and 48 hours after exposure, according to the CDC.  It causes 19-21 million illnesses per year in the United States, according to the CDC.  Norovirus is often linked to restaurant food.