Federal health officials have extended their health warning for romaine lettuce grown in the Yuma, Ariz., region. Consumers now are advised to avoid all forms of the lettuce.
Previous warnings highlighted chopped, packaged romaine and salad mixes containing the variety.
The expansion came after prisoners in Alaska fell ill after eating lettuce from whole romaine heads sourced from the Yuma area, the U.S. Centers for Disease Control and Prevention said Friday.
The unusually virulent strain of E. coli bacteria has sickened more than 50 people in 16 states, sending 31 to hospitals.
No grower or distributor has been identified as the source of the outbreak. California's major produce companies, centered around the Salinas Valley, cultivate lettuce during winter around Yuma and the adjacent Imperial Valley in Southern California.
The health agency earlier this week added 18 more victims, including nine with serious kidney failure, from five states _ Alaska, Arizona, California, Louisiana and Montana _ to an outbreak of Escherichia coli O157:H7 that started in late March.
Besides those hospitalized, 22 people have been sickened in Washington, Idaho, Missouri, Illinois, Michigan, Ohio, Pennsylvania, New York, New Jersey, Connecticut and Virginia, according to the CDC.
Here's the CDC's warning as of April 20:
_Do not buy or eat romaine lettuce at a grocery store or restaurant unless you can confirm it is not from the Yuma, Ariz., growing region.
_Unless the source of the product is known, consumers anywhere in the United States who have any store-bought romaine lettuce at home should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick. Product labels often do not identify growing regions, so throw out any romaine lettuce if you're uncertain about where it was grown. This includes whole heads and hearts of romaine, chopped romaine, and salads and salad mixes containing romaine lettuce. If you do not know if the lettuce is romaine, do not eat it and throw it away.
_Restaurants and retailers should not serve or sell any romaine lettuce from the Yuma, Ariz., growing region.
