Among the 18 ill people for whom CDC has information, nine were hospitalized, including one person in California who died.
The CDC continues to interview sick people in the United States to determine what they ate in the week before their illness started.
In Canada, health officials said romaine lettuce is now safe to eat.
In the USA, the FDA, which had not posted any public information about the outbreak until today, is assisting the CDC, but has virtually nothing to report. However, an eerily similar outbreak in the U.S.is still being investigated by the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration.
The last reported illness in the United States was on December 12, suggesting that the risk of buying food contaminated in the current outbreak had passed, the Centers for Disease Control and Prevention said in a statement on Wednesday.
To view a larger version of this information graphic please click on the image. Source CDC
In the US, the CDC did not make any recommendations to the public about avoiding any foods in its initial December 28, 2017, media statement on the outbreak or in today's update.To date, only half of the USA victims have been interviewed by outbreak investigators.
In all, 42 people, from five provinces, became ill, according to Public Health Agency Canada.
In an interview with NBC News, a CDC official said that even though Canadian authorities have linked the outbreak to romaine, US food safety workers haven't been able to identify a single food consumed by everyone affected. Canada identified romaine lettuce as the source of illnesses there, but the source of the romaine lettuce or where it became contaminated is unknown. There has been one death in California, which was previously reported as connected to the outbreak. It urged the public to avoid eating romaine lettuce until more is known about the contamination. "We're working closely with partners to identify that source", Gottlieb said. "For instance, if the equipment at a processing plant is contaminated with E. coli O157:H7, new product could become a source of further infections".
People usually get sick from this particular strain of E. coli three to four days after eating contaminated food. The E. coli lawyers of Marler Clark have represented thousands of victims of E. coli and other foodborne illness infections and have recovered over $600 million for clients.
In the meantime, we'll keep you posted on CDC and the FDAs findings of where the source of the latest E.coli outbreak is coming from.
For the record, symptoms of E. coli begin two to eight days after consuming the bacteria, notes CNN.