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If you bought romaine lettuce in the past few weeks, you should check if it's from a region in Arizona linked to an E. Coli outbreak.

The outbreak, which appears to have originated from contaminated romaine lettuce grown in Yuma, Ariz., began making people sick about a month ago, in mid-March.

"At this time, no common grower, supplier, distributor, or brand has been identified," the Centers for Disease Control and Prevention (CDC) says on its website, though health officials recommend throwing away any store-bought chopped romaine lettuce you've purchased recently.

Here's what we know about the romaine lettuce E. coli outbreak:

How many people have been sickened by the romaine lettuce E. coli outbreak?

The E.coli outbreak has sickened 53 people in 16 states and is continuing to cause illness across the country, the CDC said in an update Wednesday.

While no deaths have been reported as a result of the E. coli outbreak, 31 people who were sickened have been hospitalized "including five people who have developed a type of kidney failure called hemolytic uremic syndrome," the CDC says. Seventy percent of the people who were sickened by the E. coli romaine lettuce outbreak are female, and the median age of ill people is 34.

The CDC is maintaining a map of the E.coli outbreak so you can see what states the bacteria has been found in. So far, the states with the highest rate of illness are Pennsylvania, New Jersey and Idaho.

Should I throw out my lettuce?

"Consumers anywhere in the United States who have store-bought chopped romaine lettuce at home, including salads and salad mixes containing chopped romaine lettuce, should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick," the CDC says on its website. "If you do not know if the lettuce is romaine, do not eat it and throw it away."

The CDC also recommends asking grocery stores and restaurants where their romaine lettuce is from before you eat or purchase the leafy green. Do not eat it if it is from the Yuma, Ariz region, or if the restaurant or retailer can't confirm its origin, the CDC says.

Additionally, the CDC says that restaurants and retailers should “not serve or sell any chopped romaine lettuce, including salads and salad mixes containing chopped romaine lettuce from the Yuma, Arizona growing region,” and they should ask suppliers where their romaine lettuce comes from.

Has the romaine lettuce E. coli outbreak led to recalls?

There have been no recalls of romaine lettuce so far since people began reporting illnesses related to E. coli.

What are the symptoms of E. coli?

E.coli symptoms can take up to three days to develop, and another two to three weeks to be reported to state health officials, so even if you've eaten the romaine lettuce and don't feel sick yet, you should still get rid of it, according to the CDC.

Common E. coli symptoms can include vomiting, stomach cramps and diarrhea.