Salmonella Outbreak Linked to Onions—a Post-mortem

Reported cases: 1,642
Hospitalizations:
246
States affected:
48
Provinces affected:
7
Infectious agent: Salmonella Newport
Probable source: Red onions produced and packed by Thomson International, Inc. of Bakersfield, CA


Two months after the US Centers for Disease Control and Prevention (CDC) and the Public Health Agency of Canada (PHAC) declared this outbreak over, its root cause remains a mystery.

The US Food and Drug Administration (FDA) has plowed through more than 2,000 samples, testing finished products, swab and environmental samples from Thomson’s packing facility, and environmental samples from the vicinity of the fields where the onions were grown.

FDA labs recovered eleven different Salmonella serotypes from the various environmental samples, according to information obtained by eFoodAlert in response to a Freedom of Information Act request.

Although Salmonella Newport was found in two samples described as soil/sediment, neither sample yielded the outbreak strain recovered from patients.

Not one of the onions tested in FDA labs were Salmonella-positive.

Not one of the swab samples obtained from inside the Thomson packing facility were Salmonella-positive.

But this is not the whole story. To understand FDA’s findings, it’s important to know more about onions.

The onion

Onions can be grown from seeds, seedlings, or sets (immature onion bulbs). The crop is ready for harvest when at least one-half of the leaves are dead.

In order to ensure an adequate storage life, the onions must be left in the field to “cure” for at least 12–24 hours. This allows the outer skin to dry. Curing is complete when the neck of the onion (the top of the bulb) is dry and tight.

After curing, the onions are “topped” above the neck to remove the leaves, after which they are ready for eating or for extended storage.

Onions are closely related to garlic and, like garlic, onions produce certain essential oils that possess anti-bacterial properties. Although Salmonella can survive on onions, these essential oils complicate the process of detecting the bacteria.

Thomson’s onion operations

Onions are onions, whether grown in a small backyard or in a large commercial field. The same principles apply. The differences are those of scale.

Thomson’s onions are grown from seeds in two different parts of California. The company uses fields both near Bakersfield, where its packing house is located, and just outside Holtville, in California’s Imperial Valley, approximately 330 miles to the south.

When the onion crop is ready for harvest, Thomson’s crews use specialized equipment to dig beneath the bulbs and cut them out of the ground. The onions are left in the field to cure.

Once the onions have cured, a crew of farm laborers works its way through the field, trimming off the tops and bottoms of the onions, culling and discarding damaged onions, and placing the trimmed onions into buckets.

Culled onions and the trimmed-off tops and bottoms are left in the field to be plowed back into the soil when it is prepared for the next crop.

The full buckets are poured into burlap bags, which are left in the field for additional curing.

Once curing is complete, the onions are either shipped in bulk directly to customers or are transported to Thomson’s Bakersfield packing facility, where they are brushed clean and packed for distribution.

What FDA did not find

  • No “egregious” conditions or violations of the Produce Safety Rule
  • No direct evidence of the outbreak strain in bagged onions
  • No direct evidence of the outbreak strain in any environmental samples either at the packing facility or in and around the fields

What FDA found in Bakersfield

  • Cats in and near the onion packing lines
  • Pigeons flying or roosting inside the packing house
  • Apparent bird droppings on and near the onion packing line
  • A thick build-up of dirt and soil on the packing line even after the most recent cleaning/sanitizing activity
  • Rough, dirty weld points on the packing line
  • Inadequate documentation of cleaning/sanitizing activity
  • Swallow nests overhead within a few feet of an onion-packing line
  • Inconsistent cleaning/sanitation Standard Operating Procedures documentation
  • Inconsistent bacteriological testing of agricultural water for coliforms and E. coli.
  • Salmonella in animal scat, drain sediment, and environmental swab sample and on a water filter

What FDA found in Holtville

  • Worn and uneven areas on field packing equipment that could harbor bacteria
  • Indications of bird activity around the fields and equipment
  • Flock of birds (ibis) in field undergoing flood irrigation adjacent to field where onions had been grown
  • Salmonella, including Salmonella Newport, in several soil/sediment samples

And then there’s the water…

Information received under a Freedom of Information Act request is often heavily redacted, as anyone knows who watches The Rachel Maddow Show on MSNBC. This is what FDA’s investigation report had to say about the source of irrigation water used on the onion fields.

It would appear that irrigation water was drawn from a different source than was usual on at least one occasion. The details and date(s) on which this took place were redacted from the report, as was the diagram showing the flow of water from the source to the fields.

Why does this matter?

Irrigation water polluted by runoff from cattle feedlots has been linked to contaminated produce grown in the Salinas and Imperial Valleys in the past. A quick look at a Google map for the areas around Bakersfield and Holtville reveals the presence of feedlots in both vicinities.

The bottom line

As soon as Thomson onions were identified by CDC and FDA as the probable source of the Salmonella Newport outbreak, the company shut down its harvesting and packing operations.

By the time FDA investigators arrived on the scene, there were no field or packing activities for them to observe. The investigators were able to carry out extensive sampling of the equipment surfaces, the environment, and the stored onions, but were unable see either the harvest or packing operations in action.

Although neither FDA nor the Canadian Food Inspection Agency were able to find the outbreak strain in any of the onion samples, all of the epidemiological evidence from both the CDC and the PHAC points to Thomson’s red onions as the source of the outbreak,

The presence of multiple Salmonella-positive environmental samples lends weight to this conclusion, although the actual source of the contamination likely will never be known.

Contaminated Peaches from USA Cause Salmonella Outbreak in Canada

Thirty-three Canadians in Ontario (22 cases) and Quebec (11 cases) have become infected with Salmonella Enteritidis after consuming peaches imported from the USA, according to a report released this morning by the Public Health Agency of Canada (PHAC).

Three of the outbreak victims have been hospitalized.

Those infected with the outbreak strain of Salmonella Enteritidis range in age between 0 and 91 years, and 55% of the victims are female.

The outbreak is linked to peaches supplied by Prima Wawona, a California-based company, which has recalled a series of products from the marketplace.

Prima Wawona peaches have also been blamed for an outbreak of Salmonella Enteritidis in the USA, which had sickened 68 individuals in 9 US states as of August 21st, according to the US Centers for Disease Control and Prevention.

On August 22nd, the Canadian Food Inspection Agency (CFIA) issued a Consumer Advisory alerting Canadians to the presence of the recalled peaches in the country and warning that PHAC had identified some illnesses linked to their consumption.

Canadian consumers should avoid purchasing, serving or eating any of the following peaches, or any other food products containing these peaches.

  • Harvest Sweet Sweet 2 Eat Prima Sweet Value Wawona Yellow Peaches; PLU 4037, PLU 4038 PLU 4044,
  • Harvest Sweet Sweet 2 Eat Prima Sweet Value Wawona White Peaches; PLU 4401
  • Sweet 2 Eat Sweet O Organic Yellow Peaches; PLU 94037, PLU 94038, PLU 94044
  • Sweet 2 Eat Organic White Peaches; PLU 94401
  • Wawona Peaches; 907g / 2 lb; UPC 0 33383 32200 1
  • Wegmans Peaches; 907g / 2 lb; UPC 0 77890 49048 8
  • Extrafresh Peaches; 907g / 2 lb; 0 33383 02071 6; Codes CPO3148, CPO3164, CPO3163, CPO3186, CPO3207, CPO3213, CPO3228, CPO3265, CPO3281, CPO3302, CPO3328, CPO3354, MPO0500, MPO0503, MPO0524, MPO0671, MPO0678, MPO0689, MPO0693, MPO0703, MPO0716, MPO0725, MPO0730, MPO0767, MPO0795

Peaches imported in bulk may have been sold loose or in bulk, with or without a brand name. These peaches may have been repackaged into a variety of formats.

Except for the Extrafresh Peaches, the recall encompasses all products sold from June 1, 2020 forward.

What Consumers Need to Know

  • Do not purchase or consume any peaches listed above. If you are in doubt as to the origin of peaches which you have already purchased, throw them away and disinfect the bin in which they were stored.
  • Some of the peaches may have been supplied to restaurants, hotels, bakeries or various food service establishments, including hospitals and nursing homes and may have been used in salads, desserts or baked goods. It would be prudent to avoid all of these items, unless you can be certain they were produced using peaches not included in this Advisory.
  • If you are suffering from symptoms of salmonellosis, including low-grade fever, stomach cramps, diarrhea, and/or vomiting, consult your healthcare professional. Be prepared to provide information on the food items you consumed during the week before beginning to experience your symptoms

This is the third Canadian foodborne disease outbreak since the beginning of July, all of them linked to consumption of produce imported from the USA. Local produce is readily available during the summer months. Consider supporting your local producers instead of buying imported produce.

Salmonella Outbreak Exposes Flaw in FDA ‘Import Alert’ System

The Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), the Maryland Department of Health (MDH) and other state and local agencies continue to investigate the  outbreak of Salmonella Kiambu illnesses, which has sickened 47 people and has already claimed one life.

The CDC posted this photo with the outbreak notice, describing maradol papayas as large, oval fruits that weigh 3 or more pounds, with green skins that turn yellow when the fruit is ripe. The flesh inside the fruit is salmon-colored.” Photo courtesy of CDC

Based on sampling and analysis reported by MDH, the outbreak appears to be linked to consumption of Maradol papayas, imported from Mexico. On July 26, 2017, Grande Produce (San Juan, TX) recalled Caribeña brand Maradol papayas that were shipped to an unnamed Maryland distributor center between July 10 and July 19.

The introduction of Salmonella-contaminated papayas into the US retail market occurred despite the issuance in August 2011 of Import Alert 21-17, COUNTRYWIDE DETENTION WITHOUT PHYSICAL EXAMINATION OF PAPAYA FROM MEXICO.

What is an Import Alert?

An Import Alert informs “…FDA field staff and the public that the agency has enough evidence to allow for Detention Without Physical Examination (DWPE) of products that appear to be in violation of FDA laws and regulations.” It can be very narrow (apply to a single company or importer) or extremely broad, as in the case of Import Alert 21-17. The purpose of the Import Alert is to place the burden of proving product safety on the shoulders of the producer or importer. The first Import Alert was issued in 1974.

History of Import Alert 21-17

Mexican papayas were the source of a Salmonella Agona outbreak that sickened 106 people in 25 US states between January 1 and August 25, 2011. The outbreak was traced to several brands of papayas distributed in the USA and Canada by Agromod Produce, Inc.

During the investigation into the source of the outbreak, FDA analyzed 211 samples of Mexican papayas, finding Salmonella in 33 (15.6 percent) of them. The positive samples came from 28 different firms and nearly all the major papaya-growing regions of Mexico. In response to the extent of the contamination, FDA issued Import Alert 21-17 on August 25, 2011.

Are there any exceptions to the Import Alert?

FDA policy allows for exemptions to an Import Alert, if a company can provide evidence that their products are likely to remain in compliance with FDA laws and regulations. In the case of Import Alert 21-17, FDA considers Salmonella-negative test results from five consecutive shipments over a period of time to be evidence of probable compliance. Entities able to meet these criteria may apply for an exemption. If accepted, they are added to  the Green List appended to the Import Alert.

How does the Green List Work?

At last count, FDA has granted 98 exemptions in the nearly six years during which the Import Alert has been in force. Once granted, exemptions remain in effect unless FDA receives evidence of lack of compliance, such as a result of a consumer complaint, a Salmonella-positive routine retail surveillance sample. There is no requirement for inspection of the exempt entity’s operations, for routine or periodic submission of lab test results, or for any other form or recertification. A Green-listed entity under Import Alert 21-17 has carte-blanche to ship papayas from Mexico into the USA.

What Happens to Detained Shipments under Import Alert 21-17?

Entities whose products are detained without physical examination may apply to have those products released by submitting evidence from a third-party laboratory that the product is not contaminated with Salmonella. Otherwise, the product either will be refused entry into the USA, or will be destroyed.

The action taken last week by Grande Produce represents the second time in recent years that Caribeña brand Mexican papayas have been recalled due to Salmonella contamination. The first recall took place in May 2012 after routine testing by Caribe Produce, LTD CO discovered Salmonella contamination.

A recent search of Texas Secretary of State corporate filings revealed Raul Cano to be both the registered agent for Caribe Produce and a Managing Member/Director of Grande Produce. Both companies currently share the same street address. According to a May 2017 article published in Texas Border Business, Grande Produce is owned jointly by Raul Cano and his brother, Juan Cano.

While the identity of the Mexican grower who supplied the recalled papayas has not been determined, Chiapas-based Finca Monte Verde identifies its US distributor to be Grande Produce and identifies Caribe Produce as its contact point in the USA. Finca Monte Verde is on the Import Alert 21-17 Green List and, therefore, is exempt from automatic detention.

There is no information on either the Finca Monte Verde or the Grande Produce websites to indicate whether or not Finca Monte Verde is the sole supplier of papayas to Grande Produce. While FDA is conducting a traceback investigation of the recalled Caribeña papayas, its investigators also are working with CDC and state agencies to determine whether other brands of papayas may be implicated in the Salmonella outbreak.

Although the investigating state and federal agencies have not yet determined the origin of the contaminated papayas, or the point in the tree-to-table distribution chain at which they may have become contaminated, one thing is certain. Either the papayas entered the USA under the aegis of a Green-Listed entity or the produce was admitted as a result of a third-party lab analysis certifying a Salmonella-negative result.

As food safety advocate Bill Marler pointed out in his recent opinion piece, ‘Why the US imports tainted food that can kill you,’ FDA’s ability to carry out proactive inspections of foreign growers and packers is severely limited by budget constraints, forcing the agency to rely on the good faith and probity of these entities and of their third-party testing laboratories to deliver a safe product to US consumers.

In this case, it seems the outcome was a large gap in the food safety border wall—maybe large  enough to drive a refrigerated 18-wheeler through.

This article first appeared on Food Safety News and is reposted here with permission. Attorney Bill Marler is the publisher of Food Safety News.