Two workers have been confirmed with the Norovirus and as many as 48 others have fallen ill after eating food prepared at a Concord delicatessen, health officials confirmed Thursday.

Contra Costa County environmental health department director Marilyn Underwood said many of those who had fallen ill were from a local biotech company that had an event catered last week by the North Park Deli.

“We got calls on Monday morning that a number of employees who worked at a biotech company and had been catered by this company had gotten sick,” she said. Underwood said the illness – the Norovirus – had been traced back to the deli.

“They ate common food, at a common place so we came to the North Park deli and talked with the employees there, suspecting one of them had come to work sick,” she told KTVU. “We found that one had come to work sick to their stomach and had worked that day.”

Underwood said while health officials were at the deli they witnessed “less than stellar hand washing as they (the employees) were going about their duties handling food.”

She said the deli was closed by the health officials and ordered to undergo a thorough cleaning. North Park’s manager Johnny Kim told KTVU confirmed that two of his employees had been stricken with Norovirus. He said the restaurant had passed its last inspection without any violations and was surprised by the outbreak.

“It’s horrible,” he said of the illness outbreak. “There are things that are out of my control – the health of my employees...Unfortunately it manifested itself in this way. “

The deli was reopened Thursday after being given an all-clear by health officials.

“We were shut down for a day,” he added. “But it’s all back to normal now.”