But CDC officials said genome sequencing indicated that the bacteria is closely related to an outbreak north of the border, where 41 cases have been reported to the Public Health Agency of Canada.
According to the Centers for Disease Control and Prevention, the leafy greens are linked to an e-coli outbreak that's been linked to at least two deaths. There has also been one death in Canada.
Seattle attorney Bill Marler, whose firm Marler Clark specializes in food safety law, also recommended that restaurants consider taking romaine lettuce off the menu until the CDC clarifies its position.
But there is a simple solution: don't eat romaine lettuce.
Consumer Reports is urging residents of the U.S. and Canada to avoid eating romaine lettuce due to a recent outbreak of E coli infections.
According to the CDC, 17 illnesses in the USA have been reported in 13 states: California; Connecticut; Illinois; Indiana; Michigan; Nebraska; New Hampshire; New York; Ohio; Pennsylvania; Virginia; Vermont; and Washington, between November 15 through December 8 of 2017.
The type of E. coli that's making people sick in the U.S.is genetically similar to that found in the Canadian cases, which makes it more likely - but not guaranteed - that it comes from the same source, CDC officials have said.
It added that investigation was ongoing, and more information would be released as it became available.
The CDC has not issued specific warnings about avoiding any particular food, saying the source of the infection has not yet been identified.
"Besides, most E. coli are harmless and actually are an important part of a healthy human intestinal tract".
The CDC estimated that each year 48 million people got sick from food borne illnesses, 128,000 were hospitalised and about 3,000 die.
"However, some E. coli are pathogenic, meaning they could cause illness, either diarrhea or illness outside the intestinal tract".
Health officials said a similar strain of E. coli caused an outbreak in Canada.