Media reports say the St. Louis County Health Department has reported 14 cases of pathogenic E. coli infection since Tuesday.
The Missouri Department of Health and Senior Services is assisting local public health officials in the investigation but has not yet been able to determine the source of contamination. The Centers for Disease Control and Prevention has been notified of the outbreak.
Those sickened range in age from 11 to 94, according to the St. Louis Post-Dispatch.
Health officials have urged anyone who has experienced severe stomach cramps, nausea and diarrhea to seek medical attention.