In February, Nebraska Department of Health and Human Services officials identified six isolates of Salmonella Saintpaul. Although this is a common strain of Salmonella, during 2008, only three cases had been detected in Nebraska and only four subtypes of this outbreak strain had been identified in 2008 in the entire USA. As additional reports were made, a case control study was conducted; alfalfa sprout consumption was found to be significantly related to illness. The initial tracebacks of the sprouts indicated that although the sprouts had been distributed by various companies, the sprouts from the first cases originated from the same sprouting facility in Omaha, Nebraska. Forty-two of the illnesses beginning on March 15 were attributed to sprout growing facilities in other states; these facilities had obtained seed from the same seed producer, Caudill Seed Company of Kentucky. The implicated seeds had been sold in many states. On April 26, the FDA and CDC recommended that consumers not eat raw alfalfa sprouts, including sprout blends containing alfalfa sprouts. In May, FDA alerted sprout growers and retailers that a seed supplier, Caudill Seed Company of Kentucky, was withdrawing all alfalfa seeds with a specific three-digit prefix.