March 22, 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)External investigated a multistate outbreak of Salmonella Newport infections.

Public health investigators used the PulseNet system to identify illnesses that may have been part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting was performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on bacteria isolated from ill people showed that they were closely relatedly genetically. This means that people in this outbreak were more likely to share a common source of infection.

As of March 21, 2019, 403 people infected with the outbreak strain of Salmonella Newport were reported from 30 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 5, 2018 to February 8, 2019. Ill people ranged in age from less than one year to 99, with a median age of 42. Forty-nine percent were male. Of 340 people with information available, 117 (34%) were hospitalized. No deaths were reported.

Whole genome sequencing analysis did not identify predicted antibiotic resistance in 403 Salmonella bacteria isolates from 398 ill people and five food samples. Testing of 17 outbreak isolates using standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory confirmed these results.

Investigation of the Outbreak

State and local health departments asked ill people questions about the foods they ate and other exposures in the week before they became ill. Of 277 people interviewed, 237 (86%) reported eating ground beef at home. This percentage is significantly higher than results from a survey Cdc-pdf[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. Also, several unrelated ill people ate ground beef at the same events or purchased ground beef at the same grocery store chains, suggesting that the contaminated food item was served or sold at those locations.

Officials in Arizona and Nevada collected opened and unopened packages of ground beef from ill people’s homes. Officials also collected unopened packages of ground beef from retail locations. The outbreak strain of Salmonella Newport was identified in the ground beef. Whole genome sequencing showed that the Salmonella identified in the ground beef was closely related genetically to the Salmonella in samples from ill people. USDA-FSIS and state partners traced the source of the ground beef eaten by ill people in this outbreak to JBS Tolleson, Inc.

On October 4, 2018, JBS Tolleson, Inc. recalledExternal approximately 6.5 million pounds of beef products that may be contaminated with Salmonella Newport. On December 4, 2018, JBS Tolleson, Inc. recalledExternal an additional 5.2 million pounds of beef products.

As of March 22, 2019, this outbreak appears to be over.