Tainted irrigation water appears to be the source of a national food poisoning outbreak linked to romaine lettuce, health officials said Thursday.
About 200 people were sickened in the E. coli outbreak and five people died. The outbreak, which started in the spring, is now over, the Centers for Disease Control and Prevention said.
The illnesses in 36 states were previously traced to romaine lettuce grown in Yuma, Arizona, which provides most of the romaine sold in the U.S. during the winter.
Earlier, officials tied eight illnesses at a jail in Alaska, unable to find a single farm or packaging or distribution site associated with the break.