The US Food and Drug Administration declared an end on Friday to the largest recorded cyclosporiasis outbreak in the country, saying contaminated lettuce had been removed from the market after nearly 13,000 linked illnesses.
The parasitic infection, caused by Cyclospora, spread across 20 states this summer and was traced to fresh lettuce supplies. Regulators said the removal of the tainted product from distribution closed the months-long investigation into a foodborne event that reshaped consumer demand for salad crops.
The outbreak carried a measurable market effect. Lettuce prices dropped sharply over the summer as demand fell, with the decline steepening in August, according to inflation data released Friday. Wariness among shoppers and restaurants pushed sales down and left growers facing weaker returns.
Several food chains reported the strain earlier. The infection had already weighed on salad-focused restaurant sales during the peak of the scare, when companies cited softer demand tied to consumer caution over fresh greens.
The price movement stood apart from the broader picture. Friday’s figures showed costs for most other goods holding firm, a divergence that placed lettuce among the few items to fall sharply while general inflation stayed elevated.
Cyclosporiasis is caused by a microscopic parasite spread through food or water contaminated with feces. Symptoms include watery diarrhea, cramps, nausea and fatigue, and can persist for weeks without treatment. Outbreaks in the United States have often been linked to fresh produce.
The scale of this year’s event exceeded prior records. Earlier case counts placed the total above 11,000 across 20 states before the figure climbed toward 13,000 by the time the FDA closed the investigation.
Health officials advised consumers who purchased lettuce during the outbreak period to follow standard food-safety practices, though the agency said the specific contaminated product was no longer in circulation.
The FDA said it would publish a final assessment of the outbreak’s source and supply-chain path as part of its routine post-investigation review.