In September, genetic fingerprinting test results for an E. coli O157:H7 isolate were posted by the state of Minnesota on the national PulseNet website. Later the state of Minnesota received additional reports of illness among persons who were found to carry the same strain of E.coli O157:H7 bacteria. Epidemiologists, through food histories and a case control study, identified pre-packaged, bag lettuce, produced by the Dole Food Company, Inc., as the likely vehicle of transmission. E. coli O157:H7 was subsequently found in bagged lettuce samples and an public health alert and a FDA recall about the product was issued. Oregon and Wisconsin also found case-patients who had eaten the lettuce.