Olive Garden, Red Lobster Served Salad Linked with Cyclospora Stomach Bug Outbreak

Olive Garden and Red Lobster restaurants inadvertently served salad to their customers that has been linked with the outbreak of a diarrheal disease has been linked, at least in Iowa and Nebraska, according to reports.

The salad mix, which contained iceberg and romaine lettuce, carrots and red cabbage, was produced by the Mexican subsidiary of an American food-service company, the Food and Drug Administration said Friday.

There have already been 425 cases of cyclospora infection been reported in 16 states as of Thursday, the Centers for Disease Control and Prevention said, and the number is rising.

"It is not yet clear whether the cases reported from other states are all part of the same outbreak,"said FDA spokeswoman Theresa Eisenman. "The investigation of increased cases of cyclosporiasis in other states continues."

One Olive Garden customer said she fell ill after eating the contaminated salad.

"I felt like somebody socked me in the stomach," Megan Provost, a 29-year-old banker, told ABC News. "I wouldn't wish this on my worst enemy."

Meanwhile, food safety experts say cyclospora is too rare for the cases to be unrelated, but many questions remain.

"Cyclospora is rare -- especially in the US -- so the chances of most, not all, not being related to the same product and/or manufacturer is very, very slight," foodborne illness lawyer Bill Marler said in an email.

A statement was released from Taylor Farms said, "The Mexico facility is state of the art and has an exceptional food safety record including an exceptional facility audit in 2011 by the FDA. The company is also working with the FDA on an environmental facility assessment of Taylor Farms de Mexico and is cooperating with the FDA in their ongoing investigation."

The FDA said they plan to increase its surveillance of green leafy products being imported into the United States from Mexico.