(Reuters) - U.S. health authorities have traced at least one source of an intestinal bug that has sickened more than 400 people in 17 states to salad greens supplied to restaurants by a company in Mexico.
The U.S. Food and Drug Administration said a salad mix linked to the outbreak of cyclosporiasis was supplied to restaurants in Iowa and Nebraska by Taylor Farms de Mexico, a processor of food service salads.
The restaurants included outlets of the Olive Garden and Red Lobster chains, both of which are owned by Darden Restaurants Inc, the FDA said in an e-mail.
The FDA found that illnesses at four restaurants were traced to Taylor Farms. The agency said it will be conducting an assessment of the company's processing facility in Mexico to try to learn the probable cause of the outbreak.
The FDA said its investigation "has not implicated consumer packages sold in grocery stores."
At its most recent inspection at Taylor Farms, in 2011, the FDA said it found no notable issues. The agency said that as a result of the current investigation it is increasing surveillance on other green leafy products exported to the United States from Mexico.
It is unclear whether cases reported from other states are part of the same outbreak. The investigation is ongoing.
Cyclosporiasis is most common in tropical and subtropical regions of the world. The infection is caused by ingesting food or water containing a one-celled parasite that is too small to be detected without a microscope. Symptoms include watery diarrhea, vomiting and body aches.
Most people with healthy immune systems recover from the infection without treatment. Older people and those with weakened immune systems might be at higher risk for prolonged illness.
Reporting by Toni Clarke in Washington; Editing by Leslie Adler