And who said spinach was boring?
If the ongoing E. coli outbreak due to spinach has done one thing, it’s highlight the mystery that revolves around Salinas, California:
The sunny Salinas Valley holds a dark mystery: Why, in the past decade, have nine Escherichia coli outbreaks been linked to produce grown here?
It’s still unknown why this fertile land has been hit by what an FDA official calls “significant” crop contamination.
Throughout the picturesque terrain here, questions swirl.
Has cattle waste contaminated irrigation water? Does contaminated soil blow in the wind? Do birds feeding on cow manure carry E. coli?
Is such contamination inevitable to farms so big that the area is known as “The Salad Bowl” to the nation and world? Over 10 years, E. coli outbreaks linked to produce grown here have sickened more than 300 people and killed three.
Not even federal or state authorities know why. “That’s a very good question, and we don’t have an answer to that,” said Dr. David Acheson, chief medical officer for the Food and Drug Administration’s Center for Food Safety and Applied Nutrition. “Certainly huge amounts [of vegetables] are produced there, which is clearly a factor.”
“One thing we know about E. coli is that it’s a resident of the intestinal tract of cattle, and when the cattle manure gets into water systems, it can certainly spread and contaminate anything that the water comes into contact with,” the FDA’s Acheson said.
When investigators inspect a farm, they look at the water supply, farming and processing practices, topography, animal and bird activity, and the hygiene of individuals working the crop, officials said.
A discussion about the internalization of the bacteria by the spinach plant itself (and the bacteria working its way into the leaves) has been hopping on a microbiology listserv I watch, but there hasn’t been any real resolution as to whether that’s really a significant factor, or if authorities simply meant that the E. coli were highly adherent and not easily washed off (as opposed to being physically inside the plant’s leaves). The mystery of why this area seems to be the source of repeated outbreaks of this bacterium seems to be another black box, but it underscores the importance of taking an ecological perspective with disease development–investigating all sources and the interplay between ecosystems, rather than focusing just on the plant or the cattle and being done with it.