FOOD SAFETY NEWS – The U.S. Food and Drug Administration (FDA) on May 13 released a report on its investigation of the Salmonella Newport outbreak that caused more than 1,600 reported illnesses in the U.S. and Canada between June and October 2020.
The FDA worked with the U.S. Centers for Disease Control and Prevention (CDC), state partners, and Canadian officials (Public Health Agency of Canada and Canadian Food Inspection Agency) to investigate the case.
The outbreak was linked through epidemiology and traceback to whole red onions supplied by Thomson International Inc., headquartered in Bakersfield (Southern San Joaquin Valley) with additional operations in Holtville (Imperial Valley), California.
The outbreak is the largest Salmonella foodborne illness outbreak in over a decade.
The report released today includes an overview of the traceback investigation, subsequent on-site interviews, visual observations of the growing fields, and environmental sampling, and various factors that potentially contributed to the contamination of red onions with Salmonella.
Although a conclusive root cause could not be identified, several potential contributing factors to the 2020 Salmonella outbreak linked to red onions were identified. These include:
- potentially contaminated sources of irrigation water;
- sheep grazing on adjacent land;
- signs of animal intrusion, including scat (fecal droppings), and large flocks of birds that may spread contamination; and
- food contact surfaces that had not been inspected, maintained or cleaned as frequently as necessary to protect against the contamination of produce.
In sampling conducted in Holtville, CA, the FDA found Salmonella Newport in 10 water (irrigation, seepage, and drainage) and one sediment subsamples.
However, the whole-genome sequencing of these samples did not match the outbreak strain.
Although a conclusive root cause could not be identified, several potential contributing factors to the 2020 red onion outbreak were identified, including a leading hypothesis that contaminated irrigation water used in a growing field in Holtville, CA may have led to contamination of the onions.
Final Outbreak Information
As of October 8, 2020, this outbreak appears to be over. A total of 1,127 people infected with the outbreak strain of Salmonella Newport were reported from 48 states. There were 167 hospitalizations and no deaths reported.
Epidemiologic and traceback evidence showed that red onions from Thomson International Inc. were the likely source of this outbreak. Other onion types (such as white, yellow, or sweet yellow) were also likely to be contaminated because the onions were grown and harvested together.
On August 1, 2020, Thomson International Inc. recalled all red, yellow, white, and sweet yellow onions because they may be contaminated with Salmonella. SOURCE: CDC.
In light of this report, the FDA encourages all farms to:
- assess growing operations to ensure implementation of appropriate science and risk-based preventive measures, including applicable provisions of the FDA Food Safety Modernization Act (FSMA) Produce Safety Rule and good agricultural practices;
- implement industry-led root-cause analyses to determine how the contamination likely occurred when pathogens are identified through pre-harvest or post-harvest testing of products, or microbiological surveys;
- be aware of and consider the risks that may be posed by adjacent and nearby land uses, especially as it relates to the presence of livestock and the interface between farmland, rangeland, irrigation water, and other agricultural areas;
- consider additional tools such as pre-harvest and/or post-harvest sampling and testing of products to help inform the risk assessment and clarify the need for specific prevention measures; and
- improve traceability by increasing digitization, interoperability, and standardization of traceability records; and
- follow good agricultural practices (excerpt below) to maintain and protect the quality of water sources.
Thomson International Inc. cooperated with the FDA throughout the investigation and is continuing to engage with the FDA on the agency’s findings and recommendations.
Food safety is a shared responsibility that involves food producers, distributors, manufacturers, retailers, and regulators. Recognizing the interconnection between people, animals, plants, and their shared environment when it comes to public health outcomes, we encourage collaboration among various groups in the broader agricultural community (i.e. livestock owners and produce growers, state government, and academia) to address this issue. The FDA is committed to working with these stakeholders to advance critical work.
For More Information:
- Technical Report: Factors Potentially Contributing to the Contamination of Red Onions Implicated in the Summer 2020 Outbreak of Salmonella Newport
- FDA In Brief: FDA Releases Investigation Report Following 2020 Salmonella Outbreak Linked to Red Onions
- FDA Public Health Advisory: Outbreak Investigation of Salmonella Newport in Red Onions (July 2020)
- Salmonella (Salmonellosis)
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Stop Crapping In Our Fields
Farms and farmworkers keep having to be reminded about field sanitation requirements that have been required on US farms since at least 1998
Excerpt from “Guidance for Industry: Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables”, FDA Guidance Documents, Docket Number FDA-1997-N-0152; Issued by Center for Food Safety and Applied Nutrition, OCTOBER 1998
Other areas of training to consider include, but are not limited to, the following:
- The importance of good hygiene.
All personnel should understand the impact of poor personal cleanliness and unsanitary practices on food safety. Good hygiene not only protects the worker from illness, but it reduces the potential for contaminating fresh produce which, if consumed by the public, could cause a large number of illnesses.
- The importance of handwashing.
Thorough handwashing before commencing work with produce and after using the toilet is very important. Many of the diseases that are transmissible through food may be harbored in the employee’s intestinal tract and shed in the feces. Contaminated hands can also transmit infectious diseases.
- The importance of proper handwashing techniques.
Don’t assume that workers know how to wash their hands properly. Teach proper handwashing techniques which include the following:
- Handwashing with water. Warm water is more effective than cold water for washing hands;
- Use of soap; and
- Thorough scrubbing (including cleaning under fingernails and between fingers), rinsing, and drying of the hands. Common, or shared, towels should be not be used.
- The importance of using toilet facilities.
Teach all employees the importance of using toilet facilities connected to a sewage disposal system, or properly constructed on-site sanitary pit privies, or latrines to reduce the potential for contaminating fields, produce, other workers, and water supplies. See section V. (Sanitary Facility) for additional information about toilet facilities.