An outbreak of gastrointestinal illness among guests at a wedding reception in Brewerton July 31 was caused by food poisoning, according to the state Health Department.

About 35 people got sick at the party at Arrowhead Lodge, an Onondaga County-owned facility at Oneida Shores Park, and at least nine of them were taken to area emergency rooms.

The health department said in an email its lab tested samples collected from sick individuals and the results came back positive for staph aureus enterotoxin infection, a type of food poisoning.