Federal officials say their investigation into a Salmonella outbreak linked to Del Monte vegetable and dip trays has not identified “a single source or potential point of contamination for this outbreak.”

Five people from Minnesota and Wisconsin were confirmed infected with Salmonella Infantis in the outbreak, according to an updat from the Food and Drug Administration. That number has been holding steady since late May.

The FDA updat says there is little risk to the public at this point because the trays of fresh, pre-cut vegetables described in the initial warning from Wisconsin officials on May 21 are probably not still in consumer’s homes.

“The FDA inspected the Del Monte facility that produced vegetable trays that the Wisconsin Department of Health Services linked to an outbreak of salmonellosis. The facility was in Kankakee, IL. The FDA also investigated distribution and supplier information for produce used in the vegetable trays. These investigation activities did not identify a single source or potential point of contamination for this outbreak.”

Del Monte distributed the vegetable-dip trays to Kwik Trip convenience stores in Wisconsin and Minnesota. State authorities told federal officials the outbreak patients reported becoming ill between April 13 and May 15 this year. None required hospitalization. No one died.