Seven people in Connecticut are confirmed ill with E. coli infections in the Windham/Willimantic area, according to local news station WFSB.

The source of the illnesses is not known.

Two of the cases have developed into hemolytic uremic syndrome (HUS), a potentially fatal kidney disease associated with severe E. coli outbreaks. Those two patients remain hospitalized.

Health department authorities suspect the illnesses occurred around mid-December.