The Centers for Disease Control and Prevention has released a report on a four state outbreak that sickened 20 people. The implicated Salmonellas were linked to the same brand of cashew brie.

In keeping with its standard procedure, the CDC did not name the brand or manufacturer of the brie referenced in the report that was posted in the Morbidity and Mortality Weekly Report (MMWR).

During the spring of 2021 Food Safety News reported on Salmonella infections from patients in a Salmonella outbreak traced to Jule’s brand cashew brie based on information from the Centers for Disease Control and Prevention. Jule’s recalled all of its products in April.

In its MMWR on May 30 this year, the CDC reported that on March 30, 2021, during weekly analysis of sequenced isolates, the Tennessee Department of Health identified two Salmonella Duisburg isolates that had been determined to be closely related by whole genome sequencing (WGS). The specimens containing the isolates were from two patients who reported eating the same brand of cashew brie (a vegan brie cheese alternative) at the same restaurant.

“A search of the National Center for Biotechnology Information (NCBI) Pathogen Detection Isolates Browser identified three additional Salmonella isolates, two from patients in California and one in Florida, that were closely related genetically to the Tennessee isolates. The California Department of Public Health confirmed that one patient consumed the same brand of cashew brie before becoming ill,” according to the CDC.

Open-source access to WGS data through NCBI facilitated rapid investigation of the outbreak before it was large enough to be identified through standard multistate outbreak detection methods. Rapid detection, investigation, and product recall prevented additional illnesses, according to the CDC.

The CDC determined that the outbreak had been going on since at least Dec. 1, 2020 because of WGS testing.

State and local officials interviewed patients about the foods they ate before illness onset, including cashew brie, and where the foods were purchased. 

The Food and Drug Administration assisted with the outbreak investigation and found through product and environmental sampling at recall locations and the production facility that outbreak strains were found.

Ultimately 20 patients were confirmed in four states: California with seven Salmonella Typhimurium, three Salmonella Chester, three Salmonella Urbana, and two Salmonella Duisburg; Florida with one Salmonella Chester and one Salmonella Duisburg; Maryland with one Salmonella Urbana; and Tennessee with two Salmonella Duisburg. The median patient age was 26 years with a range of 1 to 72 years old. Five patients were hospitalized, and none died.

Among 19 patients who were interviewed, 15 reported eating the same brand of cashew brie during the week before illness onset. Thirty-six samples were collected by state and federal officials from component ingredients, in-process and finished products, and environmental swabs from the cashew brie production facility.

Based on the food sample results and FDA traceback, the cashew ingredients used to make the brie products were the likely source of contamination, according to the CDC report. Review of cashew brie production revealed no lethality treatment such as pasteurizing or irradiation before cashew processing. 

The FDA worked with the cashew supplier to ensure potentially contaminated cashews were no longer on the market and the supplier implemented corrective actions.

Outbreaks associated with raw nut and seed products are well documented, and several Salmonella outbreaks associated with cashew cheese have been reported. The lack of a lethality treatment for component ingredients can increase the risk of contamination in products that are served ready-to-eat and perceived as safe by the public. 

“The identification of two persons who became ill after eating the same uncommon food at the same restaurant, paired with detection of a rare S. Duisburg serotype, led to an early hypothesis about the source of this outbreak. Open-source access to WGS data through NCBI enabled rapid investigation of this outbreak before it was large enough to be identified using the standard multistate outbreak detection methods,” according to the CDC report. 

“Rapid detection, investigation, and product recall prevented additional illnesses, given the detection of Salmonella in 95 percent of cashew brie products collected at retail locations during this investigation.”