Bagged salad is most likely the culprit in the cyclospora stomach bug outbreak, officials have not released the brand or distributor of the infected greens.

The outbreak has infected 370 people spread across 15 states NBC reported. Officials believe the contaminated salad is no longer on shelves. Officials confirmed bagged salad as the source of contamination in Iowa and Nebraska, but patients in the 13 other states could have gotten the parasite somewhere else.

"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," Steven Mandernach, chief of the Food and Consumer Safety Bureau of the Iowa Department of Inspections and Appeals, said.

A Nebraska alert said the greens "came through national distribution channels" and "locally grown produce is not part of this outbreak," CNN reported.

A total of 143 people were infected in Iowa, about 80 percent of them consumed the same brand of packaged salad greens.

Cyclospora is a parasite that usually causes: stomach pain, nausea, gas, watery diarrhea, weight loss, decreased appetite, and fatigue, the Centers for Disease Control and Prevention (CDC) reported.

"Cyclospora is spread by people ingesting something - such as food or water - that was contaminated with feces (stool). Cyclospora needs time (days to weeks) after being passed in a bowel movement to become infectious for another person. Therefore, it is unlikely that Cyclospora is passed directly from one person to another," the CDC stated.

Doctor's usually prescribe a combination of two antibiotics to treat the infection, no other treatments are currently known.

Iowa authorities instructed consumers to wash their fresh fruits and vegetables carefully before eating them, USA Today reported.

"We're not just talking about running them under some water and giving them a little pat," Barbara Chadwick, clinical services manager for the Linn County Health Department, said. "It's about soaking them and giving them a good scrubbing."

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