Four more deaths have been linked to a national food poisoning outbreak caused by tainted lettuce. Health officials have tied the E. coli outbreak to romaine lettuce grown in Yuma, Arizona.

A total of five people have now died from the outbreak and although the tainted lettuce is off the shelves, reports of illnesses continue to come in.

According to the Associated Press, this is the nation’s largest E. coli outbreak in a decade.

Health officials say 25 more cases have emerged, raising the total number of illnesses to 197 in more than 30 states. At least 89 have been hospitalized.