No common source has been found for all 15 cases of salmonella cases reported in late May and early June in Williston, but a search for a possible food supplier responsible is going nationwide.

The original cases seemed they had a common link to Economart, but as we included further cases to the report, we could not determine the same link to the store. Therefore, the source of the cases remains unknown at this time," said Julie Goplin, an epidemiologist for the State Health Department.

"We reported all cases to the Center for Disease Control and found matches to this strain nationwide. There were 28 others in 17 states ... There may be a possible source in all the cases. If it happened about the same time in 17 other states, it leads us to believe there may be a possible common source in the supplier," Goplin said.