A recent E. Coli outbreak that was linked to romaine lettuce has been traced to at least one California farm. However, an NBC report says that’s probably not the only source of the illness. Federal health officials say 59 people were reported sick because of the outbreak, which affected a total of 15 states. The Centers for Disease Control and Prevention say 23 of the sick have had to be hospitalized, but so far no one has died because of the outbreak. Investigators located the E. Coli strain in the sediment of an irrigation reservoir on a farm in Santa Barbara County along the central coast of California. The Adams Family Farm has stopped shipping romaine lettuce and is working with investigators. Officials say not all of the illnesses can be traced to this single farm, so there’s another source of the infection still out there. “What we’re seeing is there are multiple farms, multiple processors, and multiple distributors in the various steps of the traceback and they don’t all lead back to this specific farm,” says Dr. Stephen Ostroff, a senior adviser to the Food and Drug Administration Commissioner.