A U.S. food safety summit in Maryland earlier this month has become a cautionary tale after more than 100 attendees came down with suspected food poisoning.
Most of those affected complained of diarrhea, the Maryland Department of Health and Mental Hygiene said in a statement.
Local health officials have heard from about 400 of the 1,300 attendees and are at a loss as to the exact cause of their illness.
The April 8-10 meeting at the Baltimore Convention Center included representatives from the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention, and food companies such as McDonald's Corp, Tyson Foods Inc and ConAgra Foods Inc.
"We are working on evaluating possible exposures and doing testing at the Maryland state public health laboratory to attempt to identify an agent," the health department said in the statement.
The convention center and its food service provider, Centerplate, were inspected by city health officials. Centerplate was issued a violation notice for condensation dripping from an ice machine in the kitchen, according to NBC News.
Centerplate declined a Reuters' request for comment.