US federal officials have reaffirmed that shredded iceberg lettuce supplied by Taylor Farms is the source of a multi-state Cyclospora outbreak causing severe diarrhoea, after a confusing weekend in which a false-positive test result briefly muddied the picture. The Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) had already identified Taylor Farms through repeated traceback investigations linking illnesses to lettuce grown in Central Mexico, prompting a sweeping recall of the company's iceberg lettuce sourced there between 29 June and 16 July. The episode highlights the difficulty of communicating clearly during a live food-safety investigation, especially when Taylor Farms' own public statements about the recall have remained vague.

The confusion began when the FDA announced on Saturday that a sample of Taylor Farms lettuce had tested positive for Cyclospora, seemingly confirming the traceback findings, only to retract the result on Sunday after determining it was a false positive caused by contamination during testing. Taylor Farms responded by publicly claiming the FDA had "apologised" and insisting no positive product test had ever been confirmed, a framing that fed media reports suggesting the agency had wrongly blamed the company. On Monday, FDA officials clarified that the false-positive sample was from border-tested lettuce not covered by the recall, and stressed that this result did not change the underlying basis for the outbreak investigation, which still points to Taylor Farms. Initial CDC warnings had focused on Taco Bell locations in five states—Indiana, Kentucky, Michigan, Ohio and West Virginia—though officials say new illnesses continue to be reported.