MICHEL MARTIN, HOST:
The Food and Drug Administration did an about-face in its hunt for the source of the cyclospora outbreak. On Friday, it said it identified the parasite, which can cause intense diarrhea and other illness, on a sample of iceberg lettuce from Taylor Farms in Mexico. But on Sunday, it retracted those results. The agency said a review revealed that that finding was a false positive. NPR's Yuki Noguchi reports on this confusing situation.
YUKI NOGUCHI, BYLINE: There are now over 1,600 confirmed cases of the illness caused by this water- and food-borne parasite, and a growing number of suspected cases in the thousands. Microbiologist Donald Schaffner at Rutgers University says tracing parasitic disease can be tricky because it's hard to identify from small samples that might not represent the entire crop. Often, if the source is found, it's based on patients' recollections of what they ate in recent weeks.
DONALD SCHAFFNER: We know we have a lot of sick people in Michigan and Ohio. And we know that some of those people ate Taco Bell lettuce, and CDC and FDA believe that it's the lettuce that made them sick.
NOGUCHI: That is now all health officials have to go on with the current outbreak, in the absence of genetic tests confirming the presence of cyclospora on lettuce or any other source. Despite its retraction, the FDA yesterday said it still believes this multistate outbreak to be linked to iceberg lettuce sourced from Taylor Farms in Mexico. That company had supplied Taco Bell and sold products to Walmart. It recalled its lettuce last week.
To complicate matters, since the 1990s, Schaffner says there have been several cyclospora outbreaks occurring every summer, though this year is set to break records. He says often outbreaks aren't connected or even traceable to food. A person can also get sick from drinking or swimming in contaminated water, for example.
SCHAFFNER: Just because you're sick with cyclospora right now doesn't mean that you're part of this cluster of cases that have an epicenter in Michigan and Ohio.
NOGUCHI: For now, while health officials suspect the primary contaminant is lettuce, the recommendation remains to avoid eating any of the recalled product and to wash hands and food surfaces.
Yuki Noguchi, NPR News. Transcript provided by NPR, Copyright NPR.
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