San Mateo County Director of Environmental Health Dean Peterson said that laboratory tests revealed Thursday that 62 of about 200 people attending a Redwood City-San Mateo County Chamber of Commerce event at Hotel Sofitel on Jan. 24 were infected with norovirus.

The Examiner reports that health officials had pinpointed either the salmon or chicken, which was served as the evening’s main courses, and that nobody who chose the vegetarian entrée fell sick. Contaminated workers could have been the source.

Inspectors found evidence that the Sofitel’s staff was re-using dirty towels to wipe down tables, food being kept too hot or too cold and a dishwasher who was touching clean dishes directly after touching dirty dishes. Hotel management immediately corrected the violations.