Category Archives: Salmonella in Onions

USA – Outbreak Investigation of Salmonella Oranienburg: Whole, Fresh Onions (October 2021) is Over.


The FDA, along with CDC, and state and local partners, investigated a multistate outbreak of Salmonella Oranienburg infections linked to whole, fresh onions imported from the State of Chihuahua, Mexico, in cooperation with the Mexican competent authorities. As of February 2, 2022, CDC has declared this outbreak over. CDC reports that there were 1040 illnesses in 39 states, Washington, D.C., and Puerto Rico.

In September 2021, as part of the ongoing investigation to determine the product causing illnesses, the FDA import operations implemented enhanced screening for Salmonella for onions imported into the United States, but no samples were collected because the growing season had ended and onions were no longer being imported from the State of Chihuahua, Mexico.

As a result of this outbreak, the FDA initiated onsite domestic investigations as well as Foreign Supplier Verification Program (FSVP) inspections of domestic firms who imported onions from the State of Chihuahua, Mexico. By inspecting these U.S. importers, FDA can determine if they are in compliance with applicable FSVP requirements, including performing certain risk-based activities to verify that imported foods meet U.S. safety standards.

While the outbreak has ended, FDA continues to work closely with Mexican competent authorities through the established Food Safety Partnership to investigate potential source(s) of contamination within the implicated region and to proactively implement prevention strategies ahead of the next growing season. FDA also intends to consider using additional tools, such as import screening and sampling, for onions grown and harvested in the State of Chihuahua, Mexico during the next growing season.


CDC has announced the outbreak is over. There are no recommendations for consumers, retailers, or suppliers.

Case Count Map Provided by CDC

Outbreak Investigation of Salmonella Oranienburg in Whole, Fresh Onions: Case Count Map Provided by CDC (February 2, 2022)

Case Counts

Total Illnesses: 1,040
Hospitalizations: 260
Deaths: 0
Last illness onset: January 1, 2022
States with Cases: AL, AR, CA, CO, CT, DC, FL, GA, HI, IA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MS, NC, ND, NE, NJ, NM, NY, OH, OK, OR, PA, PR, SC, SD, TN, TX, UT, VA, WA, WI, WV
Product Distribution: Nationwide

Researchers tackle Salmonella in onions

Uvalde Leader News

Salmonella contamination of bulb onions, which caused recalls across the U.S. and Canada in 2020, is the focus of a Texas A&M AgriLife Research project to help onion producers solve the problem.

Salmonella outbreaks in onions and onion products show that the pathogen might persist during production, handling or storage. This is a significant concern to the onion produce industry, researchers said.

“Little is known about salmonella’s behavior related to bulb onions,” said Vijay Joshi, Ph.D., AgriLife Research assistant professor in the Department of Horticultural Sciences and systems physiologist at the Texas A&M AgriLife Research and Extension Center at Uvalde.

Joshi’s team, over the next two years, with more than $400,000 in grant support from the Center for Produce Safety, will develop an onion-specific risk reduction plan to deliver to industry.

USA – Core Outbreak Table Updates


This week’s updates are:

  • A new outbreak of E. coli O121: H19 with an unidentified vehicle has been added. This outbreak does not appear to be ongoing, as the last illness onset occurred in November 2021. FDA has initiated traceback and other investigational activities in an effort to learn more about possible sources or routes of contamination.
  • The outbreak of Salmonella Javiana linked to 65 illnesses has ended. The information collected over the course of this investigation indicated cut cantaloupe was the likely source of this outbreak, however it appears that the products linked to outbreak illnesses are past shelf life and are no longer available for sale. The most recent illness occurred in November 2021. FDA’s outbreak investigation did not identify a specific product until after the product had expired and was no longer on the market, and there were no actionable steps for consumers to take to protect themselves.
  • For the outbreak of E. coli O157:H7 linked to spinach, the outbreak has ended and the FDA investigation has closed. This incident was archived in the 2021 Investigation Table.
1/10/2022 1050 E. coli
Not Yet
12/29/2021 1052 E. coli
Packaged Salad See Outbreak
12/20/2021 1039 Listeria
Packaged Salad See Outbreak
12/15/2021 1048 Listeria
Packaged Salad See Outbreak
11/24/2021 1044 Salmonella
Cut Cantaloupe 65
9/15/2021 1031 Salmonella
Red, Yellow,
and White Onions
See Outbreak

CPS – Research Project Funding 2022 – Bulb Onions


Assessing the potential for production practices to impact dry bulb onion safety

In 2020, the dry bulb onion industry faced their first significant outbreak of foodborne illness when red onions grown in California were epidemiologically linked to >1,000 cases of salmonellosis. Since then, industry and food safety experts have been scratching their heads to figure out how this could have happened. After review of outbreak data and consultation with various stakeholders, we have identified a small number of practices with the potential to contribute to a large-scale contamination event, through water or agricultural input contamination. We have designed field trials to determine the risks of using contaminated water source or other agricultural input when 1) applying crop protection sprays (pesticides and/or clay) and 2) during irrigation (overhead vs. drip). Our primary goal is to collect evidence demonstrating risks of these practices and to communicate our findings to relevant stakeholders to reduce the potential for outbreak like this from recurring in the future. We will share our findings via a broad outreach strategy that communicates with industry throughout the two-year study. Outreach activities culminate with the development and delivery of a workshop and best practices guide that enables growers to better understand risks and implement changes to minimize the likelihood of crop contamination.


Strategic approaches to mitigate Salmonella contamination of bulb onions

The proposal aims to address the recent multi-state Salmonella outbreak associated with red onion, resulting in nationwide recalls of onions and associated products. The outbreak highlights the pathogen’s ability to persist and survive on bulb onions during production, handling, or storage, causing significant concern to the onion produce industry. Although Salmonella’s persistence on other farm produce is documented, there is a general lack of knowledge on Salmonella’s behavior on bulb onions. We propose developing an onion-specific risk reduction plan by investigating Salmonella’s survival and growth on onion bulbs using different genetic backgrounds, nutritional compositions influenced by agronomic practices, seasons, and managed stress environments. Additionally, to understand the potential to serve as a transient host for transmission, we will investigate the effects of genetic, nutritional, and physiochemical characters on Salmonella survival and growth. This project will provide the industry with tools (1) to identify factors in the onion production and supply chain that may allow a Salmonella to persist, (2) identify varieties and agronomic practices that would minimize or eliminate its persistence, and (3) to help the produce industry in developing guidelines to manage risks of Salmonella in onions effectively.

USA – Nationwide Onion Outbreak will likely be over 1,000 by Christmas -Salmonella

Food Poison Journal

As of November 12, 2021, 892 people infected with the outbreak strain of Salmonella Oranienburg have been reported from 38 states and Puerto Rico. Illnesses started on dates ranging from May 31, 2021, to October 25, 2021.

Sick people range in age from less than 1 year to 101 years, with a median age of 37, and 58% are female. Of 571 people with information available, 183 (32%) have been hospitalized.

According to other publicly available data, we expect to see the number of sickened in this outbreak to crest 1,000.

USA – Core Table Update


A new Salmonella Javiana outbreak has been listed on the FDA’s Core Outbreak Investigation Table.  The product linked to the illnesses has not been identified.

Research – Reduction of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella on Whole Yellow Onions (Allium cepa) Exposed to Hot Water

Journal of Food Protection

In-home or food service antimicrobial treatment options for fresh produce are limited. Hot water treatments for whole (unpeeled) produce have been proposed, but data to support this practice for onions are not available. Separate cocktails of rifampin-resistant Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella were cultured on agar and suspended in sterile water. The outer papery skin at the equator or root or stem ends of the whole yellow onions was spot inoculated at 6 log CFU per onion. After drying for 30 min and, in some cases, storage at 4°C for 6 days, onions were immersed in water at ca. 100°C for 5 s or 85°C for 10 to 180 s. No significant difference (P > 0.05) in the mean decline of Salmonella was found on onions that were exposed to hot water after drying the inoculum for 30 min or after storage at 4°C for 6 days. Exposure of whole onions at 100°C for 5 s reduced E. coli O157:H7 and L. monocytogenes populations by >5 log CFU per onion at all inoculum sites and Salmonella populations by >5 log CFU per onion at the stem end and equator but not consistently at the root end. Mean root-end reductions of ≥5 log CFU per onion of E. coli O157:H7, L. monocytogenes, and Salmonella were achieved consistently when the root end was fully immersed in 85°C hot water for 45 or 60 s except in a small number of cases (4 of 57; 7%) when the root end was oriented upward and above the water line during treatment. When onions were held at 85°C for 180 s with the root end above the water line in an uncovered water bath, no significant declines in Salmonella populations were observed; significant mean declines in Salmonella were achieved (mean, 5 log CFU per onion; range, 3.49 to 6.25 log CFU per onion) when the water bath was covered. Short exposure to hot water can significantly reduce pathogens on the surface of whole onions. Reductions are more consistent when the root end is submerged and when the water bath is covered.

  • Short hot-water exposure significantly reduces pathogen populations on whole onions.
  • Salmonella reductions were greater at the stem and equator than at the root end.
  • Pathogen reduction was greater for fully submerged root ends in covered water baths.

USA – Core Outbreak Table Update


Date Ref Pathogen Product(s) Total Investigation Status
11/24/2021 1044 Salmonella     Javiana Not Yet Identified 19 Active
11/17/2021 1043 E. coli O157:H7 Spinach See Outbreak Advisory Active
9/15/2021 1031 Salmonella Oranienburg Red, Yellow, and White Onions See Outbreak Advisory Active
9/15/2021 1025 Salmonella Thompson Seafood See Outbreak Advisory Active


USA – Salmonella Onion Outbreak continues to expand after 900 sickened

Food Poison Journal

Potandon Produce L.L.C. of Idaho Falls, Idaho is updating its October 26 voluntary recall of onions supplied from Keeler Family Farms and sold as Green Giant Fresh to include 3lb. and 5lb. bags of whole yellow onions and 2 lb. bags of whole white onions shipped between July 15 and August 22, 2021 to a UNFI retail distribution center in Champaign, Illinois. This recall does not affect any other Green Giant Fresh products or include any Green Giant canned or frozen vegetable products.

The recalled onions are being recalled because they have the potential to be contaminated with Salmonella.

USA – Alsum Farms Onions Are Recalled For Possible Salmonella Contamination

Food Poisoning Bulletin

Alsum Farms onions are recalled for possible Salmonella contamination, according to an FDA notice. The fresh yellow, white, and red onions were delivered to retailers in Wisconsin, Michigan, Illinois, and Pennsylvania between July 13, 2021 and August 18, 2021. The onions were imported from Chihuahua, Mexico by Keeler Family Farms. No illnesses have been reported to date in connection with onions marketed through Keeler Family Farms. Alsum Farms & Produce is located in Friesland, Wisconsin. You can see all of the secondary onion recalls in association with a multistate Salmonella outbreak here.