SCARBOROUGH, Maine – Hannaford Supermarkets announced it has limited its ground beef supplier to a single source to ensure the product can be traced back in the event of a foodborne illness outbreak.

According to a Jan. 6 report from the Portland Press Herald, the move comes in the wake of a multi-state outbreak of Salmonella Typhimurium that has sickened 19 people. The US Department of Agriculture's Food Safety and Inspection Service is investigating the outbreak. In a Jan. 5 release, the agency reported that it was unable to determine responsible suppliers based on Hannaford's "limited records."

"FSIS recently identified this problem at the retail level and is pursuing rulemaking to address the concern," the agency said. "FSIS has not yet been able to identify FSIS-regulated suppliers of raw beef ground at Hannaford Stores related to the outbreak that could be subject to recall action."

A spokesman for Hannaford said the company is cooperating fully with the investigation and has complied with industry standards for record keeping.