Salmonella linked to onions has infected more than 650 people in 37 states, CDC says

People in the US should throw away any red, white, or yellow onions that they have bought without a sticker or packaging, the Centers for Disease Control and Prevention says, amid a new salmonella outbreak.

At least 652 people in 37 states have caught salmonella linked to onions imported from the Mexican state of Chihuahua, the CDC said Friday after first announcing the outbreak Thursday. The actual number of people infected could be higher because some people may not have been tested for the bacteria, the CDC said.

Texas appears to be the worst-hit state, with 159 infections recorded, the CDC data shows.

Salmonella bacteria usually cause diarrhea, fever, and stomach cramps lasting about a week. But some people, especially, those 65 and older, kids under 5, and those with weakened immune systems, may require medical treatment.

In the current outbreak, 129 people have needed hospital treatment but nobody has died, the CDC said.

The CDC said the onions linked to the outbreak were distributed by ProSource Produce LLC and Keeler Family Farms and were sold to restaurants and grocery stores throughout the US under brands including Big Bull, Peak Fresh Produce, Sierra Madre, Markon First Crop, Markon Essentials, Rio Blue, ProSource, Rio Valley, and Sysco Imperial.

It said investigators were trying to figure out whether other onions and suppliers were linked to the outbreak.

The onions from Chihuahua were recalled Thursday and were most recently imported into the US on August 31, the CDC said. They could last three months in storage, however, and could still be in homes and businesses across the US.

It urged businesses and people at home to check their onions and wash any surfaces that the onions could have touched.

If you can't tell where an onion is from, throw it away and don't buy or eat it, the CDC said.