December 30, 2019

CDC, public health and regulatory officials in several states, and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) investigated a multistate outbreak of Salmonella Dublin infections linked to ground beef.

Since the last update on November 18, 2019, two additional ill people were reported from Colorado and New Mexico. A total of 13 people infected with the outbreak strain of Salmonella Dublin were reported from eight states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.

Illnesses started on dates ranging from August 8, 2019, to October 22, 2019. Ill people ranged in age from 39 to 74 years, with a median age of 66. Sixty-two percent of ill people were male. Of 11 ill people with information available, 9 (82%) were hospitalized. One death was reported from California. In six (46%) ill people, Salmonella was found in samples of blood, which indicates their illnesses may have been more severe. Salmonella Dublin is known to commonly cause more severe illnesses than other Salmonella strains, particularly in older people.

Whole genome sequencing analysis did not identify any antibiotic resistance in 20 bacterial isolates from 13 ill people and seven food specimens. Testing of two clinical isolates using standard antibiotic susceptibility testing methods by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) confirmed these results.

Investigation of the Outbreak

Epidemiologic, traceback, and laboratory evidence indicated that ground beef was the likely source of this outbreak.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Of nine people interviewed, eight (89%) reported eating ground beef at home. This percentage was significantly higher than results from a survey pdf icon[PDF – 787 KB] of healthy people in which 40% of respondents reported eating any ground beef at home in the week before they were interviewed. Ill people reported buying ground beef from various stores.

Laboratory testing identified the outbreak strain of Salmonella Dublin in repackaged leftover ground beef collected from an ill person’s home in California. The outbreak strain of Salmonella Dublin was also identified in six samples of raw beef products from slaughter and processing establishments. Samples from slaughter and processing establishments were collected as part of FSIS’s routine testing under the Salmonella performance standards. WGS showed that the Salmonella strain from these samples was closely related genetically to the Salmonella from ill people. These results provided more evidence that people in this outbreak got sick from eating ground beef.

USDA-FSIS and state partners traced the source of some of the ground beef eaten by one ill person in this outbreak to Central Valley Meat Co., Inc. On November 15, 2019, Central Valley Meat Co., Inc., recalledexternal icon 34,222 pounds of ground beef produced that may be contaminated with Salmonella Dublin.

A single supplier, distributor, or brand of ground beef was not identified that could account for all the illnesses in this outbreak.

As of December 30, 2019, this outbreak appears to be over.