Cyclospora Outbreak Is Ending, Here’s What That Means for Unresolved Cases - Newsweek

Federal officials are expected to declare an end to the nation's largest known cyclosporiasis outbreak, , potentially closing the chapter on a foodborne illness event that sickened more than 19,500 people across the United States and left investigators searching for answers they may never find.

The news came according to a Washington Post report published Thursday afternoon, citing two unnamed sources. The Food and Drug Administration (FDA) has not publicly confirmed that an announcement is imminent. But according to the report, officials are preparing to formally declare the outbreak over after case counts and new reports declined in recent weeks.

"[T]he Administration will continue to rigorously monitor, [assess], and respond to all disease threats to the American people," a White House official told Newsweek on Thursday afternoon.

Newsweek reached out to the FDA and the Department of Health and Human Services (HHS) by email for comment.

The outbreak's scale was unprecedented. Prior to 2026, the worst U.S. Cyclospora season on record occurred in 2019, when federal health officials documented roughly 4,700 illnesses.

The outbreak's reach was amplified by Taylor Farms products' role in major food-service supply chains. FDA records show recalled products were packaged for multiple food service and retail operations, including brands under Yum! Brands and other large restaurant chains. Early in the investigation, many illnesses were associated with people who reported eating at Taco Bell locations, helping investigators narrow their search.

While federal investigators eventually linked the largest outbreak cluster to shredded iceberg lettuce, scientists never identified a cyclospora-positive lettuce sample. And although lettuce emerged as the leading suspect based on epidemiological and traceback evidence, the precise point at which contamination occurred may never be known. Cyclospora can be difficult to trace and contaminated produce often disappears from the supply chain long before testing begins. By the time outbreaks are recognized, the food responsible has frequently been consumed or discarded.

The uncertainty extends beyond the Taylor Farms-linked illnesses. Federal health agencies have repeatedly said they are investigating multiple Cyclospora outbreaks and thousands of additional illnesses that appear unrelated to the lettuce cluster. In many of those cases, no definitive source was ever identified. And, according to University of Florida food sciences professor Keith Schneider, it probably never will be.

"If they couldn't find the definitive cause for the lettuce, they're not likely to find definitive cause for the others, either," Schneider told Newsweek.

As a result, the end of the outbreak does not necessarily bring all of the answers public health officials hoped to find.

Cyclospora is a microscopic parasite that causes cyclosporiasis, a gastrointestinal illness that spreads through contaminated food or water. It can cause severe and explosive diarrhea, stomach cramps, nausea and fatigue, and outbreaks in the U.S. are often linked to fresh produce, including cilantro, berries, and lettuce.

The parasite can be difficult to remove from produce even with washing. Heat inactivates the parasite, but most impacted produce is eaten raw.

Cyclospora cases typically increase during the warmer months, but outbreaks on this scale are exceptionally uncommon in the United States. In a typical year, the CDC records only around 1,000 cases, making the more than 19,500 laboratory-confirmed infections reported since May an unprecedented surge. Historically, Cyclospora season peaks during the summer and tapers off by late August. Public health tracking has often used August 31 as a rough endpoint for the annual surge in infections. This year's outbreak far exceeded anything previously recorded, but Schneider said the outbreak associated with Taylor Farms was an "anomaly" and unlikely to happen at such magnitude again.

However, because of improved testing for Cyclospora and increased awareness of the parasite, more cases might be reported in the future.

"I think what we're going to see is because of the increased awareness of Cyclospora and increased efforts with better testing methodologies, we will be able to identify it more frequently," Schneider told Newsweek. "So the background noise [the cases that occur annually] will probably go up moving forward because we're more sensitized to it and better at detecting it, but the actual number occurring year-to-year will be about the same."

Health officials say consumers do not need to avoid lettuce because the products linked to the outbreak have long since been removed from the food supply. The best-by dates for the recalled Taylor Farms de Mexico shredded iceberg lettuce products have passed, and the products should no longer be available in stores or restaurants.

Cyclospora is spread when food or water becomes contaminated with the parasite, often before products reach consumers. Past U.S. outbreaks have been linked to items such as leafy greens, cilantro, basil and other fresh produce. Because the parasite can be difficult to detect, washing fruits and vegetables may reduce dirt and bacteria but cannot guarantee the removal of Cyclospora contamination.

Consumers are generally at lower risk when eating produce that is cooked before consumption, such as squash or green beans, since heat can kill many pathogens. Fruits and vegetables with thick, peelable skins, such as bananas, oranges, avocados and melons, are also considered less vulnerable to contamination reaching the edible portion because the outer rind or peel is discarded before eating.

For now, federal agencies appear ready to move from emergency response to reflection. Investigators have spent months tracing produce shipments, interviewing patients and inspecting facilities in both the United States and Mexico. Those efforts established strong evidence connecting the largest outbreak cluster to shredded iceberg lettuce, but they did not provide all of the answers officials sought.

Cases often continue to surface long after contaminated food is off the market because people may not develop symptoms for days or weeks, and public health agencies can take additional time to confirm and report infections. If the FDA does formally declare the outbreak over, it would mark the end of a crisis that stretched through much of the summer. It would not, however, resolve every mystery.

Contact Newsweek editors on this story: Jason Lemon and Gray R. Thomas