As of May 23, 2023, 18 people infected with the outbreak strain of Salmonella have been reported from 6 states. Illnesses started on dates ranging from February 27, 2023, to May 2, 2023.

Public health officials collect many different types of information from sick people, including their age, race, ethnicity, other demographics, and the foods they ate in the week before they got sick. This information provides clues to help investigators identify the source of the outbreak.

Sick people range in age from 14 to 68 years, with a median age of 47, and 83% are female. Of 14 people with race or ethnicity information available, all reported non-Hispanic white. Of 14 people with information available, 2 have been hospitalized. No deaths have been reported.

State and local public health officials are interviewing people about the foods they ate in the week before they got sick. Of the 14 people interviewed, 12 reported eating food from Papa Murphy’s. Nine people ate Papa Murphy’s raw chocolate chip cookie dough or raw S’mores bars dough, and one person ate baked cookies made with Papa Murphy’s chocolate chip cookie dough.

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS).

WGS showed that bacteria from sick people’s samples are closely related genetically. This suggests that people in this outbreak got sick from the same food.

WGS analysis of bacteria from 18 people’s samples did not predict resistance to any antibiotics. Standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory is currently underway.

Papa Murphy’s has temporarily stopped selling their raw chocolate chip cookie dough and raw S’mores bars dough. CDC is advising people to check their refrigerator and freezer for these raw doughs and to throw any away. CDC always advises people not to eat raw cookie dough, unless it has a label indicating that it is safe to be eaten raw.