Ten cases of E.coli infection in Minnesota residents are now identified and linked to the multi-state outbreak.
The Minnesota Department of Health is working with the Minnesota Department of Agriculture, the Centers for Diseases Control and Prevention, the U.S. Food and Drug Administration and public health agencies in other states to investigate an outbreak.
Last week, the CDC announced that one person had died; the death, in California, was the first known fatality.
The CDC said romaine lettuce from the Yuma growing region appears to be responsible.
People should not eat or purchase romaine lettuce unless it's confirmed the lettuce was not grown in the Yuma, Ariz. region, the CDC said. "This advice includes whole heads and hearts of romaine, chopped romaine, baby romaine, organic romaine, and salads and salad mixes containing romaine lettuce". Romaine lettuce has a shelf life of several weeks, and contaminated lettuce could still be in homes, stores, and restaurants. Following the May 6 report on one case in North Dakota, also not yet included in the national count, it appears the romaine outbreak continues to expand.
The number of people infected by the romaine lettuce could still increase, due to cases after April 17.
"Illnesses that occurred in the last two to three weeks might not yet be reported because of the time between when a person becomes ill with E. coli and when the illness is reported to CDC", the website reads.
Conducting a traceback investigation from farm to plate is far from a direct line, but more of a massive web that requires tedious detective work, said Faith Critzer, a produce safety specialist and associate professor of food sciences at WSU extension in Prosser. "We may not get there".
Although E. coli is typically to primarily pose a danger to elderly people and very young children, the median age of those affected in this outbreak is 29. Previously, the CDC warned that the strain of E. coli identified, O157:H7, is particularly virulent and known to be associated with higher hospitalization and complication rates. Four new sates have reported people getting sick, including Florida.
Antibiotics are not recommended for patients with suspected E. coli O157 infections until diagnostic testing can be performed and E. coli O157 infection is ruled out. In Pennsylvania, 20 people are sick.