E. coli investigation closes, but source of the outbreak remains unknown, Arkansas Department of Health confirms

FILE - This colorized 2006 scanning electron microscope image made available by the Centers for Disease Control and Prevention shows E. coli bacteria of the O157:H7 strain that produces a powerful toxin which can cause illness. Health officials are investigating an outbreak of E. coli food poisoning among students at the University of Arkansas in late August 2023, with dozens reporting symptoms and several needing treatment in the hospital. (Janice Haney Carr/CDC via AP, File)

FAYETTEVILLE -- An Arkansas Department of Health investigation into an E. coli outbreak in Northwest Arkansas last month was unable to pinpoint the outbreak's source, the department confirmed Monday.

Surveys of sick individuals and testing of food samples failed to reveal what led to the infections, the department said Monday afternoon.

The department surveyed more than 3,200 people in the search, identifying five confirmed and 37 probable cases. Four of the confirmed cases had been hospitalized but have since been released. No suspected cases were reported after Aug. 25, according to previous department statements.