From August 6 through 24, 7 residents of Livingston County, New York, suffered from serious E. coli O157:H7 illnesses.  Four were hospitalized, and all lived in the same geographic area.

Health officials were able to identify a common outbreak strain for 5 of the 7 cases. Water in the geographic area where victims live has tested negative for E. coli contamination. While all 7 cases are geographically clustered, health officials said they do not all share the same source of public water. That includes the 5 cases linked with the common strain.

Livingston County Public Health Director Joan Ellison says the investigation is only at its halfway point and the possibility of water being a common source has not yet been ruled out.

Ellison Monday renewed a public health warning for Livingston County. The alert reminds the public that severe and persistent diarrhea, some bloody, are among the classic symptoms for E. coli infection.