CDC is collaborating with public health officials in many states, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA/FSIS), and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of Salmonella serotype Chester infections.

As of June 18, information had been collected on 14 ill and 21 well persons. Preliminary analysis of this study suggests eating a Marie Callender’s frozen meal as a possible source of illness. Ill persons (86 percent) were significantly more likely than well persons (10 percent) to report eating a frozen meal. All ill persons (100 percent) who ate frozen meals reported eating a Marie Callender’s frozen meal. None (0 percent) of the well persons who ate a frozen meal reported eating a Marie Callender’s frozen meal. At this time there are insufficient data to implicate a specific frozen meal type. However, many of the ill persons have reported eating a Marie Callender’s cheesy chicken and rice frozen entrée in the week before becoming ill.

Today, the Minnesota Department of Agriculture Laboratory reported to CDC that it has isolated Salmonella Chester from an unopened package of Marie Callender’s Cheesy Chicken & Rice single-serve frozen entrée collected from a case patient. Subtyping of the Salmonella strain is under way.

As of June 18, 2010, a total of 30 individuals infected with a matching strain of Salmonella Chester have been reported from 15 states since April 11, 2010. The number of ill people identified in each state with this strain is as follows: CA (4), CO (2), GA (6), IL (1), KY (1), MA (2), MN (2), MO (1), NC (1), OK (1), OR (2), SC (2), TN (1), UT (1), and VA (3). Among those for whom information is available about when symptoms started, illnesses began between April 5, 2010 and May 29, 2010. Case-patients range in age from <1 to 88 years old, and the median age is 37 years. Fifty-four percent of patients are female. Among the 15 patients with available hospitalization information, 6 (40%) were hospitalized. No deaths have been reported.