Just to clarify, because everyone now seems VERY confused: Taylor Farms de Mexico has still been implicated in this cyclospora outbreak. The recall of shredded iceberg lettuce from last week still stands. The false positive test was on lettuce coming over the border from Mexico that was NOT part of the recall. If that positive had been accurate, it would have meant *more* lettuce needed to be recalled. In foodborne illness outbreaks *we often do not ever get positive tests to tie product to illness* especially for highly perishable products like lettuce. It's common to rely on other epidemiological evidence, as FDA and CDC are doing here. Prediction: This is a public health communications nightmare that will be studied for a long time.