US stores are recalling onions over contamination fears amid a salmonella outbreak that has caused over 600 people to fall ill.
On 1 August, Thomson International recalled their red, yellow and white onions that had been shipped across all 50 US states and Canada since 1 May.
Salmonella cases have been reported in 43 states as well as Canada.
Salmonella can cause diarrhea, fever and cramps. Children and the elderly are more prone to severe illness.
Possibly contaminated onions were sold to wholesalers, restaurants, and retail stores, according to the US Food and Drug Administration (FDA). They were sold under a number of brand names or in loose containers at grocery stores.
US stores, including Walmart, Kroger, Food Lion, Publix, and Giant Eagle have issued recalls on onions or prepared food products - like salads and deli items - that may contain the affected shipments. On Monday, Trader Joe's and Ralph's stores on the West Coast also began recalling onions.
Canadian health officials have confirmed over 200 Salmonella cases linked to imported US onions. Canadian-grown onions are not affected.
According to the Centers for Disease Control (CDC), 85 Americans have required hospital care for a salmonella infection as of 7 August. Salmonella symptoms typically appear between six hours to six days after exposure.
Most people will recover without treatment in four to seven days, though in some severe cases, the bacteria may spread from the intestines to other parts of the body.
"Children younger than five years, adults 65 years and older, and people with weakened immune systems are more likely to have a severe illness," the CDC said.
The FDA, CDC and Public Health Agency of Canada have launched an investigation into the outbreak.
Health officials have advised consumers to throw away any onions or products containing onions if their origin is uncertain. Even cooked food is a risk as the bacteria can spread to other surfaces or items in the kitchen.
The FDA advises consumers sanitise any surfaces that may have come into contact with recalled onions, like refrigerators, storage bins or cutting boards.