The number of people sickened at the Hilton Westchester a week ago appears to be in the hundreds as health officials try to determine what caused the intestinal outbreak.

Early indications are that the vomiting and diarrhea were caused by a norovirus, the Westchester County Department of Health said.

Jane Lerner of The Journal News reports the department would not estimate how many people became ill, but people who were at events there put the number in the hundreds.

Guests at a black-tie dinner held April 20 by the Pelham Picture House and an event the following day have reported developing symptoms soon after.

“I was as sick as a dog for five days,” Beryl Savage of White Plains said Monday. “I was so weak, I couldn’t even stand up.”

Organizers have said that 200 guests at the brunch got sick. It was not clear how many people who attended the Pelham Picture House event the night before came down with the illness.

Peter DeLucia, assistant commissioner of the agency’s Bureau of Public Health Protection, said the county won’t know for sure until Wednesday, but early indications are that the illness was caused by a norovirus. He urged people who are sick to stay home until they are better to prevent the spread.

Hilton officials said they were cooperating with the department.

The kitchen has not been closed, but special precautions are being taken there, including eliminating self-service buffets and public touch screens and increasing the use of sanitizers.

The infosheet below is from a norovirus outbreak at a Chicago Hilton in 2007.