In April and May of 1998, public health officials in eleven states received an unusually high number of reports of illness attributed to Salmonella Agona. The number of illnesses represented an eightfold increase over the median number of Salmonella Agona cases reported in those states from 1993 to 1997. A case-control study determined that a majority of cases had consumed Millville brand plain Toasted Oats cereal before becoming ill. Salmonella Agona was found in the Toasted Oats cereal and was genetically indistinguishable from the stain of Salmonella Agona that had been isolated from the ill people. Salmonella can survive for long periods in dry environments such as cereal.