The Kane County Health Department is trying to trace the source of a salmonella outbreak at an Aurora grocery that sent one person to the hospital, according to the Chicago Tribune.

The investigation has not been expanded beyond the four confirmed and 17 suspected cases of salmonella infection identified last week in connection with take-out food purchased at El Paso Grande Grocer.

The store, which is closed temporarily and is cooperating with investigators, prepares some foods for take-out "and the individuals who are ill had purchased the food as take-out items."

The county Health Department is awaiting the results of laboratory tests by the state in an effort to identify a potential source of the contamination.