Cyclospora cases in 15 states have been linked to iceberg lettuce, U.S. health officials said Wednesday, adding six states with cases tied to the ongoing outbreak. The Centers for Disease Control and Prevention said the number of states tied to the deadly outbreak had grown from nine to 15. Many cyclospora cases are never linked to a specific food or other source. Adding in the other states that have reported cases, the national total stands at over 25,000. The FDA says it is tracking five separate ongoing cyclospora outbreaks.