In a follow-up on the multistate outbreak of E. coli O157:H7 infections linked to chopped romaine lettuce, the Centers for Disease Control and Prevention (CDC) is reporting an additional 18 cases in the investigation.

53 people infected with the outbreak strain of E. coli O157:H7 have been reported from 16 states. Alaska, Arizona, California, Louisiana, and Montana have been added to the list of states reporting infections. Thirty-one people required hospitalization, including two people who developed a type of kidney failure called hemolytic uremic syndrome.

No deaths have been reported.

The source of a multistate Escherichia coli O157:H7 outbreak has been linked to chopped romaine lettuce from the Yuma, Az., growing region.

CDC recommeneds people who have store-bought chopped romaine lettuce at home, including salads and salad mixes containing chopped romaine lettuce, should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick.

If you do not know if the lettuce is romaine, do not eat it and throw it away. Before buying romaine lettuce at a grocery store or eating it at a restaurant, confirm that it is not chopped romaine lettuce from the Yuma growing region. If you cannot confirm the source of the lettuce, do not buy or eat it.

Restaurants and retailers should not serve or sell any chopped romaine lettuce from the Yuma, Arizona growing region. Ask your suppliers about the source of their chopped romaine lettuce.