1 of 2 | The U.S. Centers for Disease Control and Prevention headquarters are shown in Atlanta, Ga. The largest U.S. outbreak of cyclosporiasis has been linked to six more states, the CDC said Wednesday. File photo by Erik S. Lesser/EPA-EFE

Aug. 5 (UPI) -- An outbreak of cyclosporiasis cases tied to recalled iceberg lettuce has now been expanded to 15 states, the U.S. Food and Drug Administration said Wednesday.

While cyclosporiasis has been confirmed or suspected in 47 states, these cases are ones that have been connected to shredded iceberg lettuce that was sold at restaurants including Taco Bell and some grocery stores. That outbreak, which has been the largest one and is centered in Michigan, was traced to lettuce sourced by Taylor Farms in central Mexico.

Taylor Farms de Mexico announced July 17 that it was voluntarily recalling all iceberg lettuce from that area. This included shredded lettuce used in Taco Bell products and in salad kits sold in some grocery stores. Taco Bell also said it was removing shredded lettuce supplied by Taylor Farms in affected states.

On July 24, that outbreak affected people in Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia. On Wednesday, the FDA and U.S. Centers for Disease Control and Prevention said cases in Missouri, Arkansas, Iowa, Nebraska, New Hampshire and North Carolina are also considered part of that outbreak.