A lettuce linked last week to the cyclosporiasis outbreak is no longer believed to be a culprit, the Food and Drug Administration said Sunday.

On Thursday, public health officials said they believed lettuce supplied by Taylor Farms and served at Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia likely was linked to the cyclosporiasis outbreak. But after the FDA re-reviewed the sample, it determined the link was a false positive. The FDA said its findings do not "represent true amplification" and removed information about the contaminated sample from a Saturday update.

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The FDA said federal and state partners are continuing to collect samples and analyze products, but there are currently no confirmed positive samples as of Sunday.

Taco Bell said it voluntarily removed the lettuce thought to be contaminated from its stores, and Taylor Farms recalled lettuce grown in Mexico and supplied to 27 states, including New Jersey and Pennsylvania. Taylor Farms and the FDA are continuing to work to remove any product connected to the outbreak from the market.

Cyclosporiasis is an intense intestinal illness causes by a parasite, and it usually is contracted by consuming food or water that has come into contact with feces containing eggs from the parasite. It can be difficult to identity, because tests used to detect food poisoning don't typically search for the cyclospora parasite, leading to underreporting. Technicians also can't grow it in a lab, so generating evidence from produce thought to be contaminated can be difficult.

The CDC has reported 1,644 cases and 94 hospitalizations nationwide from cyclosporiasis as of Friday. However, the real number is likely much higher, because the CDC doesn't report probable cases. Michigan, one of the centers of the outbreak, has reported 5,000 cases.

In an alert issued Thursday, the Pennsylvania Department of Health said it has confirmed 28 cases in 2026. However, officials said additional reports have been received and investigations are underway, and they expect case counts to increase.