The deadly Salmonella outbreak in western Kentucky has grown to 15 cases in three counties. The outbreak is already blamed for one death and for sending five people to area hospitals. Hopkins, Webster, and Muhlenberg counties have reported illnesses, according to Kentucky’s Cabinet for Health and Family Services. A genetic “fingerprint” associated with the outbreak has been linked to at least eight of the region’s Salmonella cases. The state said that the Hopkins County Health Department is conducting the investigation to determine the source of the Salmonella. The department is collecting patient and food samples, but has not said how long it might take before the source will be found. The three adjacent counties are located south and west of Louisville. Salmonella is a foodborne illness known for causing diarrhea, fever and vomiting.