Protecting families from contaminated food and water
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Protecting families from contaminated food and water
Posted in Our Blog,Outbreaks & Recalls on December 8, 2022
Could we see a lettuce recall soon?
It is about that time of year again. Holiday shopping and family get togethers? Well… That too. But no. I mean another lettuce recall.
Why do I think we may see a lettuce recall soon? Lets take a walk down memory lane.
The biggest issue started in 2017 in the Yuma growing region of Arizona. Environmental samples linked the outbreak strain to water sample collected along a 3.5 mile stretch of an irrigation canal in the Wellton area of Yuma County. Investigators noted that “there were no E. coli O157:H7 illnesses identified in the Yuma growing region prior to the time of the likely contamination event, therefore a human source for the outbreak is considered unlikely.” While the cause remained uncertain, interviews with growers and pesticide applicators concluded that it could have been due to direct application of irrigation canal water to the lettuce crops or using irrigation canal water to dilute crop protection chemicals applied to the lettuce crops.
Again in 2018 in the Santa Barbara growing region in California was associated with an E. coli outbreak linked to romaine lettuce. This prompted regulators to take a closer look at traceability practices and testing procedures to reduce the risk of this happening in the future and track it for better recall response if it did.
Did it work? Survey says… No. In 2019, there were 3 separate outbreaks linked to romaine lettuce. While they were all outbreaks of a Shiga toxin-producing strain of E. coli (STEC), E. coli O157:H7, there were three distinct strains determined by Whole Genome Sequencing (WGS). One of the outbreak strains matched a fecal-soil composite sample from a cattle grate on public land less than two miles upslope from a produce farm implicated in the outbreak.
While not linked as a genetic match to any of the 3 outbreak strains, additional environmental sampling uncovered other STEC strains nearby in a border area of a farm immediately next to cattle grazing land in the hills above the growing fields and in two samples from on-farm water drainage basins.
About this time again in 2020 there was another romaine lettuce linked outbreak, though no particular source could be confirmed.
This again happened in 2021 where an E. coli outbreak strain was linked to romaine lettuce from the Yuma growing region of Arizona.
That brings us to this year. So, I ask again. Could we see a lettuce outbreak soon? And why is it cyclical?
It all has to do with where lettuce is grown and when.
Like most vegetables, unless grown hydro- or aqua-ponically or in green houses, lettuce thrives in certain regions during certain times of the year. In the Summer months, most of the United States has growing conditions suitable for the leafy green, though perhaps not in as strong of a consistency.
Most of the U.S. grown lettuce comes from California, which produces about 70% of the lettuce consumed in the country each year. Arizona follows with about 20% of the volume, and the remaining 10% is scattered.
The San Joaquin Valley region of California can grow in the Spring and Fall, the Central Coast region of California can grow between April and November, and the California desert region takes over November to March.
Arizona is prime lettuce climate from April to November.
As you can see, there is a shift in growing regions when the majority of the outbreaks begin to take place, historically speaking. Is there a root cause for all of them?
Up stream feed lots seems to be a common denominator in these food sources. This puts growers at the mercy of gravity.
Feed lots are a common source of E. coli, as it thrives in the digestive system of large animals. This moves to their waste, which is regulated by another agency assigned to cattle farms. While this potential source of E. coli contamination is largely managed, run-off into streams and water systems is still a risk.
These same streams and water systems are potentially used as a source for irrigation in the thirsty lettuce crops.
Perhaps certain times of the year more than others, these sources are used for irrigation. Some locations may be more vulnerable due to their reliance on this water source.
Farms who participate in regional grower organizations have procedures in place to test irrigation water for contamination. However, evidence suggests that this is not 100%.
Either the testing is not done at an effective frequency, sampling is inadequate, or some other potential reason – outbreaks continue to happen.
In response to these outbreaks, an organization known as The Leafy Greens Marketing Agreement (LGMA) program was created, just for these two states. In California, the California Department of Agriculture operates the program and in Arizona, it is overseen by the Arizona Department of Agriculture.
This program uses state government auditors to verify that participating businesses and farms are following a set of required food safety practices and traceback systems that enables them to track any product back to the field where it was grown.
While these practices should help prevent issues leading to outbreaks, it is not infallible. So at least the traceback aspect of it seems to be effective.
In fact, farms and packagers are now required to label their product to indicate the growing region to assist in recall response to outbreaks. The map used for this purpose can be found here via a table for “Where is my Romaine Lettuce From.”
While the farms get most of the blame, other sources could be the ones potentially holding the smoking gun. Every step in the process allows for an opportunity for contamination.
Irrigation is generally the first thought, but processing facilities also touch a large amount of product. These facilities are generally used by several farms. Though these facilities sanitize the lettuce before chopping it, a breach could lead to contamination of hundreds of pre-cut salad bags.
The issue isn’t specifically risky for romaine. All leafy greens suffer the same vulnerabilities due to the nature of the product. It grows near the ground in open fields and isn’t protected by rinds or shells like other fruits and vegetables says CDC Health Communication Specialist Brian Katzowitz, which contributes to the risk.
According to Purdue University food science professor Amanda J. Deering, romaine and spinach have been linked to E. coli more than other greens not due to a more innate risk, but likely due to its popularity. The more romaine being consumed, the potentially higher rate of infection.
Stay tuned to MakeFoodSafe.com for the latest in food safety news and outbreak alerts. We hope that this year will be calm, but be prepared with information.
By: Heather Van Tassell (contributing writer, non-lawyer)