EVANSVILLE, Ind., Nov. 22 (UPI) -- Forty people are sick from an E. coli outbreak linked to California-grown romaine lettuce, the U.S. Food and Drug Administration said Friday.
Anyone with romaine lettuce that came from Salinas, Calif., should throw it away and wash and sanitize the drawers or shelves where it was kept, the Centers for Disease Control and Prevention said in a recall announcement.
Likewise, if it's unclear where the romaine was grown, it should be thrown away.
"This advice includes all types of romaine lettuce, whole heads of romaine, hearts of romaine and packages with precut lettuce and salad mixes that contain romaine, including baby romaine, spring mix and Caesar salad," the CDC recall announcement said.
The outbreak has spread to 16 states, and 28 of the 40 infected people are hospitalized, officials said. No one has died.
This is the fourth E. coli outbreak caused by romaine lettuce since early 2018.
In spring 2018, an E. coli outbreak that originated in romaine lettuce grown in the Yuma, Ariz., growing region made 62 people sick.
That fall, a second outbreak, which killed five people and sickened 210, was traced to California.
Then in October, the FDA announced a third outbreak, also traced to California, had made 23 people sick.
In each case, the FDA was unable to trace the contamination to a single grower.
"There may be something more dispersed in the environment of the region that needs to be controlled," said Jennifer McEntire, vice president of food safety and technology for United Fresh Produce Association of Washington, D.C.
The FDA began testing romaine lettuce in California and Arizona this month in an effort to determine what is causing the contamination.
"This assignment is intended to help the FDA, the CDC and state public health agencies to identify sources of contamination and factors that may be contributing to them, so that they can be addressed," the FDA said in a statement.