Illnesses linked to a deadly E. coli outbreak in romaine lettuce are continuing to rise, with 28 additional people found to have been sickened by the bacteria since last week, bringing the total to 149, health officials said.
As of this week, people in 29 states have fallen ill from consuming tainted lettuce traced to the Yuma, Arizona, region, the Centers for Disease Control and Prevention said on Wednesday. Investigators have failed to determine a more precise source of the bacteria, which is transmitted from human or animal feces.
“Do not eat or buy romaine lettuce unless you can confirm it is not from the Yuma growing region,” the CDC warned. “Romaine lettuce has a shelf life of several weeks, and contaminated lettuce could still be in homes, stores, and restaurants.”
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This advisory includes whole heads and hearts of romaine, chopped romaine, baby romaine, organic romaine, and salads containing romaine lettuce.
“If you do not know if the lettuce in a salad mix is romaine, do not eat it,” the CDC advises.
Do not eat or buy romaine lettuce unless you can confirm it is not from the Yuma growing region."
The most recent reports of illnesses started on April 25, though the CDC noted it can take up to three weeks for a confirmed illness to be reported to federal officials. That suggests there could be additional cases that are not yet known to authorities.
A total of 64 people have been hospitalized in the outbreak, including 17 who developed a type of kidney failure called hemolytic uremic syndrome. One death was reported in California, where the majority of the cases have been reported.
Pennsylvania, Idaho and Minnesota also report a high number of illnesses.
The strain of E. coli behind the outbreak is known as O157:H7, which produces a toxin that causes more severe illness, the CDC said.
The current outbreak is the worst since 2006 when E. coli contaminated spinach killed three people and sickened 199 others across 26 states.
This article originally appeared on HuffPost.