CDC is collaborating with public health officials in several states and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) to investigate a multistate outbreak of Salmonella Typhimurium infections linked to eating ground beef purchased from Hannaford Supermarkets.

Representatives from Hannaford have been cooperating with public health officials throughout the investigation. Public health investigators are using DNA "fingerprints" of Salmonella bacteria obtained through diagnostic testing with pulsed-field gel electrophoresis (PFGE) to identify cases of illness that may be part of this outbreak. Investigators are using data from PulseNet, the national subtyping network made up of state and local public health laboratories and federal food regulatory laboratories that performs molecular surveillance of foodborne infections.

Preliminary testing shows that the outbreak strain of Salmonella Typhimurium is resistant to several commonly prescribed antibiotics. This antibiotic resistance may be associated with an increase in the risk of hospitalization or possible treatment failure in infected individuals.

A total of 16 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 7 states. The number of ill persons identified in each state is as follows: HI (1), KY (1), MA (1), ME (4), NH (4), NY (4), and VT (1). Among persons for whom information is available, illnesses began on or after October 8, 2011. Ill persons range in age from 1 year to 79 years old, with a median age of 45 years old. Fifty percent are male. Among the 13 ill persons with available information, 7 (54%) have been hospitalized. No deaths have been reported.

Among 16 ill persons for whom information is available, 11 (69%) reported consuming ground beef in the week before their illness began. Among the 11 cases who reported consuming ground beef, 10 (91%) reported purchasing ground beef from Hannaford stores. For ill persons for whom information is available, reported purchase dates range from October 12, 2011 to November 20, 2011.

On December 15, 2011, Hannaford, a Scarborough, Maine-based grocery chain, recalled an undetermined amount of fresh ground beef products that bear sell-by dates of December 17, 2011 or earlier.