The State Health Department says the investigation into an E. coli outbreak in the St. Louis area is over.

Director Margaret Donnelly says the inspections and food trace-back investigation by federal agencies were extensive, but did not reveal a definitive source. She says a grower in California was suspected of being connected but records were “insufficient to complete the picture.”

She told the House Appropriations Committee on Health, Mental Health and Social Services it is not unusual for a source to go unidentified. “The food which caused the outbreak is identified in less than 50 percent of food bourne outbreaks, and the reason for that is because of the amount of time that passes from when the person is exposed to the pathogen until the public health receives a report. This incubation period can be up to ten days. In addition, after that period of time, food products are often no longer available for analysis.”

The outbreak cost the Department 25 thousand dollars in lab costs that Donnelly says were absorbed by its normal appropriation. 60 people were infected in 10 states; 37 of those were Missourians.