The FDA has released an investigation report into the Thomson red onion Salmonella outbreak that took place n the summer and fall of 2020. the report details the factors that may have contributed to the contamination of the onions. At least 1,127 American and 515 people in Canada were sickened in this outbreak, which was the largest Salmonella outbreak in more than ten years. The outbreak was also unusual because red onions had not been associated with a foodborne illness outbreak before.
The outbreak strain of Salmonella Newport was not identified in any of the nearly 2,000 subsamples tested, but 11 subsamples, which included ten water and 1 sediment, that were collected near the growing fields identified in traceback were positive for Salmonella Newport. A conclusive root cause could not be identified, but several potential contributing factors were found. A leading hypothesis was that contaminated irrigation water used in a growing field in Holtville, California may have led to the contamination.
One of the issues about this investigation is that it did not occur during any harvesting activities or while packaging activities were ongoing. But visual observations of the implicated fields suggested several opportunities for contaminating including irrigation water, sheep that were grazing on adjacent land, and signs of animal intrusion. Scat (animal feces) and large flocks of birds were present.
Review of the packing house practices confirmed many opportunities for spread of foodborne pathogens, including signs of animal and pest intrusion as well as food contact surfaces that were not inspected, maintained, cleaned, or sanitized as often as necessary to protect the crop. Thomson International cooperated with the FDA throughout the investigation and is still engaging with the government on the findings and recommendations of the investigation.
Salmonella Newport isolates from two sediment subsamples and two water subsamples collected during the investigation were genetically related, through whole genome sequencing, to clinical isolates from 2016 and 2018 foodborne illness outbreaks associated with the consumption of sprouts. This fact may be indicative of human pathogen persistence and distribution in the growing region, which is a concentrated area of seed for sprouting production. This could pose a risk of contamination for any produce, although sprouts were not a food vehicle of interest in the red onion outbreak.
The FDA is urging growers to conduct risk assessments that include valuation of hazards that may be associated with adjacent and nearby land uses. This is the same advice that the government has given to romaine lettuce growers in California and Arizona. The presence of livestock and wildlife and potential runoff into growing fields and water sources are an important factor in contamination and these outbreaks, so incidents like the Thomson red onion Salmonella outbreak do not happen n the future.
If you or a loved one have been sickened with a Salmonella infection or an E. coli infection after eating recalled onions or romaine lettuce, please contact our experienced lawyers for help at 1-888-377-8900 or 612-338-0202.
