Purpose: The purpose of the investigation was to identify the vehicle responsible for the outbreak and take appropriate actions to protect public health.
Methods: A case was defined as an infection with the outbreak strains of Salmonella Newport, Salmonella Hartford, or Salmonella Oranienburg occurring between 1/21/14 ̶ 7/22/14. Food exposure questionnaires were examined to help determine a food vehicle. FDA and state partners conducted an informational traceback investigation to identify common manufacturers and sources of chia seeds. A total of 216 samples were collected including retail product samples, consumer samples, and investigational samples consisting of environmental swabs and product samples.
Results: A total of 31 cases from 16 states were identified, while 19/21 (90%) of cases with available information reported exposure to a chia seed product. A Canadian manufacturer was the source of the final sprouted chia powder product, obtaining the suspect lot of chia seeds from two farms in Argentina. Thirty-four samples from multiple lots of sprouted chia seed powder products yielded multiple serotypes of Salmonella. The investigation resulted in voluntary recalls by multiple firms as well as increased import surveillance. The recalled products were distributed to numerous countries and as a result, an International Food Safety Authorities Network (INFOSAN) alert was issued by the World Health Organization.
Significance: FDA and CFIA were not able to confirm whether the source of the Salmonella contamination originated with chia seeds or the processing thereof. This outbreak involved a novel, raw food product that has a small but growing population of consumers.