Multistate Outbreak of Salmonella Braenderup Linked to Nut Butters

The CDC is collaborating with public health officials in several states and with the FDA to investigate a multistate outbreak of Salmonella Braenderup infections. Results from this ongoing investigation indicate that almond and peanut butter manufactured by nSpired Natural Foods, Inc., is the likely source of this outbreak.


Public health investigators are using the PulseNet system to identify cases of illness that may be part of this outbreak. PulseNet, the national subtyping network of public health and food regulatory agency laboratories coordinated by the CDC, receives DNA "fingerprints" of Salmonella bacteria obtained through diagnostic testing using pulsed-field gel electrophoresis, or PFGE. Whole genome sequencing, a highly discriminatory subtyping method, was also used to define the outbreak strain. Whole genome sequencing helped clarify which illnesses were related to the outbreak.


Symptoms of Salmonella include: Diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts 4 to 7 days, and most people recover without treatment.


In some persons, the diarrhea may be so severe that the patient needs to be hospitalized. Salmonella infection may spread from the intestines to the bloodstream and then to other body sites and can cause death unless the person is treated promptly with antibiotics. Children younger than five years, older adults, and people with weakened immune systems are more likely to have a severe illness from Salmonella infection.


As of August 20, 2014, a total of four ill persons infected with the outbreak strain of Salmonella Braenderup have been reported from four states since January 1, 2014. The number of ill persons identified in each state is as follows: Connecticut (1), Iowa (1), Tennessee (1), and Texas (1).


Illness onset dates range from January 22, 2014, to May 16, 2014. Ill persons range in age from 3 years to 83 years, with a median age of 36 years. Seventy-five percent of ill persons are female. Among three ill persons with available information, one (33%) reported being hospitalized. No deaths have been reported.


Illnesses that occurred after July 30, 2014 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of two to four weeks. The recalled peanut and almond butter products have a long shelf life and may still be in people’s homes, and illnesses may continue to be reported.


During routine inspections at an nSpired Natural Foods facility in Ashland, Oregon, in January and July 2014, the FDA isolated Salmonella Braenderup from environmental samples. PFGE and whole genome sequencing were performed on the environmental isolates by the FDA to further characterize the bacteria.


A subsequent search of the PulseNet database identified ill persons with the same PFGE “fingerprint” of Salmonella Braenderup. The CDC performed whole genome sequencing on these clinical isolates and determined that the bacteria from the ill persons were related to the environmental isolates taken from the firm.


To date, three of the four ill persons were interviewed and answered questions about foods eaten and other exposures during the week before becoming ill. All three (100%) of them reported eating peanut or almond butter, and all three (100%) reported eating a brand of peanut or almond butter produced by nSpired Natural Foods, Inc. The recalled brands include Arrowhead Mills, MaraNatha, Trader Joe’s, Whole Foods, Safeway, and Kroger. A complete listing of all of the recalled products is available on the FDA website.


See the CDC Report


See also Medical Law Perspectives, July 2012 Report: Foodborne Illness: When Grabbing a Bite Can Be Deadly