U.S. health officials are investigating a multi-state outbreak of Shiga toxin-producing Escherichia coli (E. coli) O121 infections linked to raw clover sprouts that have sickened as many as 10 people, the U.S. Food and Drug Administration (FDA) announced May 22. Half of those who fell ill have been hospitalized, the FDA said, but no one has developed hemolytic uremic syndrome and no deaths have been reported.

The FDA said it is investigating the outbreak — which has been linked to raw clover sprouts from Evergreen Fresh Sprouts LLC of Moyie Springs, Idaho — along with the Centers for Disease Control and Prevention (CDC) and state and local officials. A CDC report said that as of May 21, there were seven confirmed and three probable cases of E. coli illnesses, three in Idaho and seven in Washington.

"We are moving quickly to learn as much as possible and prevent additional people from becoming ill," the FDA said in a statement. "We recognize that people will be concerned about this outbreak, and we will continue to provide updates and advice."

Citing reports from the the Washington State Department of Health (WDOH), and the Idaho Department of Health and Welfare (IDHW), the FDA said the contaminated sprouts were eaten in sandwiches at several food outlets in Washington and Idaho, including Jimmy John's Gourmet Sandwiches in King and Spokane counties in Washington and Kootenai County, Idaho, as well as and two Pita Pit locations in Spokane County (WA) and Daanen’s Deli in Kootenai County (ID). The FDA added that Evergreen also distributed sprouts to other restaurants and some retail grocery stores in the region.