The St. Louis Post-Dispatch reports that St. Louis Missouri Health officials say there are now 30 confirmed cases of E. coli in the St. Louis area. Most of the confirmed cases have been linked to Schnucks salad bars. However, no left over products have tested positive for E. coli.

KMOX Radio reports that 21 of the cases are from St. Louis County others are in Illinois and in Boone County Missouri.

St. Louis County Health Department spokesman Craig LeFebvre says the source remains a mystery despite several foods that have been tested.

Officials with the Food and Drug Administration are now in St. Louis, working with the Centers for Disease Control and Prevention and state health officials. They are looking at upstream suppliers of lettuce as a possible source of the outbreak.