Florida, Minnesota, North Dakota and Texas are the latest states to report illnesses, bringing the total to 29.
California leads the nation with 30 cases, followed by Pennsylvania with 20, and Idaho with 11.
The most recent illness started on April 25, said the CDC, noting that illnesses since then may not have been reported yet to the agency.
There are now no food recall warnings linked to this outbreak.
1 death, formerly reported, Happened in California. Of the 129 patients the CDC has information on, half have been hospitalized.
Symptoms of E. coli begin on average three to four days after the bacteria are consumed. "Most people get diarrhea [often bloody], severe stomach cramps and vomiting", according to the CDC.
Most people recover within the first week, according to the CDC, but some infections can be severe.
Even if the person with symptoms does not recall eating any lettuce, if they develop symptoms of E. coli infection, it is important to stay hydrated and treat them seriously.
One person died. Health officials said the tainted lettuce was grown in Yuma, Arizona. The rest of the cases involve chopped lettuce that did not come from the Yuma farm, according to the U.S. Food & Drug Administration. The vegetable's 21-day shelf life means that romaine lettuce from this region may still be in the supply chain. Therefore, it is not being sold or served anymore.
In April, health officials warned consumers to toss out any romaine lettuce they might have purchased in stores.
"We are investigating dozens of other fields as potential sources of the [tainted] chopped Romaine lettuce", Harris said.
Jaron Barnes, produce department manager at the Walmart in Rexburg, said that E. coli is something they take very seriously and they have done everything they can to prevent customers from consuming any contaminated lettuce.