FDA: Irrigation ‘most likely’ E. coli source
The U.S. Food and Drug Administration released its final assessment of last spring’s E. coli illness outbreak tied to Yuma-grown romaine lettuce Thursday, finding that irrigation water was “most likely” the source of contamination.
FDA investigators drew three samples from a 3.5mile stretch of canal in the Wellton, in east Yuma County, which were the only ones out of all the environmental sampling done in the area which tested positive for E. coli 0157:H7 bacteria with the same genetic fingerprint as the strain that made 210 consumers sick in 36 states.
Five patients died from complications of the illness, which include hemolytic uremic syndrome, a form of kidney failure.
The FDA first announced the finding of the three positive samples in June, leading to speculation that the contamination came from a large stockyard that is also on the canal, maintained by Five Rivers Cattle Feeding.
But the investigation’s final report says there’s no obvious way for any kind of fecal contamination from the animals to reach the canal, and a “limited number of samples” from the property did not produce any
positive results for that E. coli strain.
The investigation did not reach a conclusion of how the bacteria from the water would have reached the “harvestable portions” of the lettuce crops, but it could have come through direct application or the mixing of canal water with chemicals before they were sprayed onto the crops.
“FDA cannot rule out that there are other sources or means of romaine lettuce contamintation that were not identified during the (environmental assessment) regulation,” the report said.
The assessment did refer to a freeze that occurred at the end of February. “This freeze event likely led to damage of some portion of the romaine lettuce crop, which may have rendered it more susceptible to microbial contamination,” it read.
How the canal water got tainted is also not clear,
given the lack of evidence it came from the Five Rivers lot or for any other means of transmission.
There is no information on how the contamination could have been able to evade the routine testing of water and crops done in the field and at salad processing plants.
The report includes five recommendations for growers and processors of fresh leafy greens to reduce the potential for contamination:
• Make sure all water applied to the harvestable portions of crops is safe for its intended use.
• Assess and address risks related to nearby land uses, including concentrated animal feeding operations (CAFOs).
• Verify that food safety measures are consistently used in all steps of the growing and processing chain.
• When a foodborne pathogen is identified while growing or processing leafy greens, a root cause analysis should be performed.
• Growers, agencies and associations from the Yuma
growing region, which includes Yuma County and Imperial County, Calif., should continue looking for other possible sources of contamination, from E. coli and other pathogens.
State Rep. Tim Dunn, RYuma, was one of four legislators who sent a letter to the FDA on Sept. 28, urging the release of the FDA’s final assessment of the outbreak by Oct. 5, approximately 30 days before the first Yuma harvest.
On Thursday Dunn said he was pleased by what was and wasn’t in the report, even though it came almost a month later than he’d asked.
“It shows that the industry has best management practices in place, the LGMA (Arizona’s and California’s leafy green marketing agreements) was the model for existing produce safety rules when they were adopted.
The lack of them being able to show any missteps the industry could have potentially done, it shows that the industry is producing safe produce,” he said.
“It talks about a weather event and the probability that weather event caused a series of perfect storms that created this tragic event,” he said.
Given the report’s focus on the contaminated water samples found in a canal within the WelltonMohawk Irrigation and Drainage District network, General Manager Elston Grubaugh said he is aware of area growers already taking some of the additional measures the new FDA report recommends.
“I am aware that there is more of a move to use treated water for application of field insecticides,” he said. “I think we were seeing more people move to groundwater as the feed water for their field applications,
or using a treatment for water they are going to apply with the chemicals, to the field.”
Grower Gary Pasquinelli said, “We are testing the heck out of the water, additives to overhead water to neutralize any pathogens in them, to negate them, so leafy greens will not be contaminated from overhead water.
“These products, there are two or three or four of them, chlorine based things, we were using them before but everyone’s using them now.
“We’re also treating water trucks that spray roads near fields, in case some of that should splash onto the product, and make sure that water is safe, also.
“We’ve improved our
food safety even more, it was already at a tremendous state,” he said. “We haven’t sat back and said ‘business as usual. I’m confident that due to these increased measures, we’re going to have a really good, safe season,” he said.
He said the first lettuce harvest of this season happened on Thursday, iceberg grown by his company on Sharp Ranch in east Yuma County.
It was cut by Ippolito International, which sells under the Queen Victoria brand name, after 58 days. “The quality is good, and the market is good, so we’re optimistic, very optimistic,” Pasquinelli said.