JoNel Aleccia of The Seattle Times writes that food vendors at the Russell Investments Center in Seattle were cleared by inspectors and allowed to reopen Wednesday, days after an outbreak of highly contagious norovirus sickened hundreds who worked in the high-rise building.

Of 600 people who attended a catered event at the building Dec. 1, more than 200 people reported suffering symptoms of norovirus, which causes acute vomiting, diarrhea and gastrointestinal distress, officials with Public Health — Seattle & King County said.

Many more — perhaps hundreds — may actually have fallen ill but were not documented. After health officials had enough evidence to confirm norovirus as the culprit, they stopped tallying survey results, said James Apa, a spokesman for the agency.

“Not collecting more data on magnitude; no indication from building or clients of new outbreak or spread to other locations,” Apa said in an email.

The 42-story building at 1301 Second Ave. was cleaned top to bottom, with special attention to high-touch sites such as doorknobs and elevator buttons, health officials said.

The site houses several high-profile clients, including Zillow, Nordstrom and Marler Clark, the Seattle food-safety law firm.

At least 150 people who responded to a survey put out to guests who attended a catered event at the Russell Investments Center Building in downtown Seattle last Tuesday, report feeling ill afterwards.

An additional 50 cases were reported directly to Public Health — Seattle & King County.

Health department investigators have sent surveys to 600 people who attended the event. As of Monday morning, only 200 have responded.

All food service operations in the building at 1301 2nd Avenue have been shut down during the investigation and cleaning process. 

Health officials believe a private cafeteria inside the building may have been where the virus started.

Norovirus is highly contagious and quickly causes sickness.  It’s believed that people who may have been sickened by food then spread the virus.