Updated: Tue, 30 Jul 2013 19:04:00 GMT | By JoNel Aleccia, NBC News

Bagged salad caused parasite outbreak, Iowa officials say

Bagged salad contaminated with the rare parasite cyclospora appears to be the source of a food poisoning outbreak that started in Nebraska and Iowa.

Bagged salad contaminated with the rare parasite cyclospora appears to be the source of a food poisoning outbreak that started in Nebraska and Iowa.

Prepackaged salad mix appears to be the source of an outbreak of food poisoning caused by a rare parasite that started in Iowa and Nebraska and may have sickened more than 370 people in 15 states, Iowa's top food inspector said Tuesday.

"The evidence points to a salad mix containing iceberg and romaine lettuce, as well as carrots and red cabbage as the source of the outbreak reported in Iowa and Nebraska," said Steven Mandernach, chief of the Food and Consumer Safety Bureau of the Iowa Department of Inspections and Appeals.

Iowa officials did not name the brand or the producer of the bagged salad mix and they did not say whether it was an imported or domestic product.

"Iowans should continue eating salads as the implicated prepackaged mix is no longer in the state's food supply chain," Mandernach added.

Federal health officials did not immediately confirm the source of the outbreak, which has sickened 373 people in 15 states, according to a Tuesday update from the Centers for Disease Control and Prevention. David Werning, spokesman for the Iowa inspection agency, said that the Food and Drug Administration would be taking over the investigation.

"FDA is following the strongest leads provided by the states and has prioritized ingredients of the salad mix identified by Iowa for traceback investigation, but is following other leads as well," agency officials said in a statement Tuesday.

It is not yet clear whether the cases reported in the various states are all part of the same outbreak, the FDA added.

Iowa investigators found that the salad mix from a single source was a common exposure in 80 percent of the cases, officials said. As of Tuesday, there were 143 reports of illness in Iowa. Nebraska officials also confirmed that the salad mix was the likely source of the outbreak, said Leah Bucco-White, a spokeswoman for the Nebraska Department of Health and Human Services. As of Tuesday, there were 78 cases in that state.

Gathering the information was challenging because most of the sick people ate the salad mix during the past several weeks and by the time the parasitic illness was identified, most of the product was no longer on store shelves, Iowa officials said. In addition, it can take a week or more after eating contaminated foods for people to develop symptoms of cyclospora infection.

Cyclospora is a rare parasite typically spread by feces in contaminated food or water. It causes lingering diarrhea and other flu-like symptoms. It can be treated with common antibiotics, but the test to confirm cyclospora infection isn't commonly performed and must be specially requested.

Iowa officials said they would continue working with other states, the FDA and the CDC as the investigation continues. Health departments reporting illnesses include those in Iowa, Nebraska, Texas, Wisconsin, Arkansas, Connecticut, Florida, Georgia, Illinois, Kansas, Minnesota, Missouri, New Jersey, New York, New York City and Ohio.

This is a
developing news story. Please check back for updates.

more video