Indiana state health officials have pinpointed the deli and bakery departments of a Greenwood Wal-Mart as the source of a salmonella outbreak that sickened at least 84 people this summer.

"We believe food handlers who didn’t have any symptoms may have contaminated the deli and bakery products," Lynae Granzow, enteric epidemiologist with the Indiana State Department of Health, said in a written statement.

Overnight from Friday to Saturday, an outside contractor performed a "deep cleaning" on the area, said Mia Masten, director of corporate affairs for Wal-Mart’s Midwest division. In addition, all prepared foods were discarded, Masten said.

Wal-Mart employees are fully trained in health and safety precautions, including hand washing, but "we are reminding our associates of those protocols," Masten said.

The state health department was contacted July 11 by the Marion County Health Department about an increase in salmonella cases, beginning in May. As of Monday, 84 cases had been reported.