More bags of spinach tainted with toxic E. coli bacteria have been found and could help investigators track down an outbreak that may have killed three people, the U.S. Centers for Disease Control and Prevention said in an interview with an Reuters on Tuesday.

Investigators found the bags in Pennsylvania, Illinois, and Ohio. The CDC said the DNA "fingerprint" of the strain isolated in Pennsylvania matches that of the outbreak strain. "’DNA fingerprinting’ is underway on the strains isolated in Illinois and Ohio," the CDC said in a statement. 

183 people in 26 states had been confirmed with E. coli O157:H7 infections in the outbreak. The Toronto Star newspaper said a woman in Canada’s Ontario province had also been infected.