Health officials say there are now 30 confirmed cases of E. Coli in the St. Louis area.

KMOX Radio reports that 21 of the cases are from St. Louis County. But the question remains: What is the source of the outbreak?

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.