The number of people sickened by a parasite linked to bagged salad mixes has gone up to 641 cases in 11 states, federal health officials said.
Of those infected in the multistate outbreak of Cyclospora, 37 were hospitalized, the Food and Drug Administration said. There were no deaths reported.
Cyclospora is a microscopic parasite that affects the intestinal tract and causes diarrhea that can last for more than a month. Symptoms typically appear about a week after consuming contaminated food or water.
The recalled products were made in the Fresh Express production facility in Streamwood, Illinois.
The salads contained iceberg lettuce, red cabbage and carrots and include products made by Fresh Express for retail store brands sold at ALDI, Giant Eagle, Hy-Vee, Jewel-Osco, ShopRite and Walmart, according to the FDA.
"Investigators continue to look into whether other retail brands may be impacted," it said.
The cases were reported between May and this month in nearly a dozen states. They were in Georgia, Iowa, Illinois, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Pennsylvania, South Dakota and Wisconsin.
Federal officials are urging people not to eat the salads as they work with companies to figure out where the products originated.
Unlike some other foodborne illnesses, Cyclospora doesn't have a DNA-fingerprint technology that can pinpoint where the product comes from. The FDA's epidemiologic investigation helped determine that the product was sold at several stores, it said.
At ALDI, the product goes under the name Little Salad Bar. At Hy-Vee, it is all the store brand garden salad products. At Jewel-Osco, the salad was sold under the name Signature Farms, and at Walmart it was sold as the Marketside brand Classic Iceberg Salad.
The recalled products were sold in at least 30 states. They include Arkansas, Connecticut, Delaware, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Montana, North Carolina, North Dakota, Nebraska, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Tennessee, Virginia, Vermont, Wisconsin, West Virginia, and the District of Columbia.
More than 600 people in 11 states get infections linked to bagged salad