Cyclospora Outbreak Expands Across the United States as Lettuce-Linked Cases Reach 20 States
Washington, August 28, 2026: A major foodborne illness outbreak caused by the parasite Cyclospora cayetanensis is continuing to affect communities across the United States, with federal health officials investigating thousands of infections and a separate multistate outbreak linked to recalled iceberg lettuce.
The scale of the outbreak has made cyclosporiasis one of the country’s most closely watched food-safety stories of the summer.
According to the latest Centers for Disease Control and Prevention data, 17,180 laboratory-confirmed cases acquired in the United States had been reported between May 1 and August 24. The same data included 922 hospitalizations and two deaths.
Lettuce-Linked Outbreak Spreads to More States
The FDA and CDC have been investigating a multistate outbreak associated with processed iceberg lettuce sourced from central Mexico.
By August 27, federal officials said the specific lettuce-linked outbreak had reached 20 states, with 11,458 people reported sick. Georgia, Tennessee and Texas were among the states newly added to the outbreak investigation.
The investigation has focused on iceberg lettuce produced at a farm in central Mexico operated by Taylor Farms.
U.S. and Mexican authorities are working together to inspect facilities and collect samples as investigators attempt to determine how the parasite entered the food supply.
Recalled Lettuce Was Removed From the Market
Taylor Farms de Mexico voluntarily recalled certain iceberg lettuce products on July 17.
The recalled products were distributed through restaurants, food-service operations and retail channels.
Federal officials say the products connected to the specific outbreak should no longer be available because their best-by dates have passed and the recalled lettuce has been removed from the market.
Taco Bell also stopped using lettuce from the identified supplier during the outbreak investigation.
The recall significantly reduced the possibility of continued exposure to the particular product under investigation, although health officials have continued receiving reports because illnesses can take time to identify and report.
Why Case Numbers Continue Rising After a Recall
The increase in reported cases after a food recall can appear confusing.
Cyclospora infections are not always diagnosed immediately.
The CDC says it can take approximately six weeks from the beginning of symptoms for a case to reach its surveillance system. Some people recover without seeking medical care, while others may not receive the specialized testing needed to identify the parasite.
As a result, newly reported cases do not necessarily mean people were recently exposed to contaminated lettuce.
Some of those individuals may have become sick weeks earlier.
Cyclospora Is a Microscopic Parasite
Cyclosporiasis is an intestinal infection caused by Cyclospora cayetanensis.
The parasite is microscopic and cannot be identified simply by looking at food.
People can become infected after consuming food or water contaminated with the parasite.
Fresh produce has been associated with previous Cyclospora outbreaks, making contamination somewhere along the agricultural or processing chain a major food-safety concern.
Symptoms Can Last for Weeks
Cyclosporiasis can cause intense gastrointestinal illness.
Common symptoms include:
- Frequent watery diarrhea
- Stomach cramps
- Nausea
- Loss of appetite
- Fatigue
- Weight loss
- Bloating and increased gas
Some patients can experience symptoms that improve and then return.
Untreated infections may persist for weeks or longer and can cause dehydration or other complications, particularly among vulnerable patients.
Two Deaths Reported in Michigan
Two deaths associated with the wider cyclosporiasis outbreak were reported in Michigan earlier this summer.
Michigan health authorities said both individuals had significant underlying medical conditions that may have been worsened by cyclosporiasis and dehydration.
Deaths from cyclosporiasis are considered uncommon, but severe dehydration and complications can make the illness dangerous for some patients.
The deaths highlight why people experiencing persistent diarrhea or other severe symptoms should seek medical attention.
The National Numbers Are Even Larger
The lettuce-linked outbreak represents only part of the national cyclosporiasis situation.
CDC surveillance through August 24 recorded 17,180 laboratory-confirmed domestically acquired cases across 48 states and the District of Columbia.
The CDC also said it was aware of another 11,844 cases that were either not laboratory confirmed or still required investigation to determine whether they were acquired domestically.
This means the eventual total could be considerably higher than the confirmed figure.
Not Every Case Is Connected to Lettuce
Health officials have emphasized an important distinction.
Although the iceberg-lettuce investigation has identified a significant multistate outbreak, not every Cyclospora infection reported in the United States has been linked to that outbreak.
The CDC is investigating at least six other clusters whose sources have not yet been confirmed.
Cyclospora cases occur naturally during the U.S. spring and summer season, which runs approximately from May through August.
Therefore, investigators must determine whether individual infections belong to the lettuce outbreak or have separate sources.
Why Tracing Cyclospora Is Difficult
Identifying the origin of a Cyclospora outbreak is challenging.
The parasite can contaminate produce without visibly changing its appearance, smell or taste.
Patients also have to remember what foods they consumed days or weeks before becoming ill.
Investigators must then compare thousands of individual food histories to search for common exposures.
The absence of rapid, highly precise genetic fingerprinting comparable to methods commonly used for bacterial pathogens can make the process even more complicated.
Food-Safety Investigations Continue in Mexico
The FDA has been conducting inspections and sampling at lettuce-growing and processing locations in central Mexico.
The agency is coordinating with Mexican authorities as investigators examine agricultural and processing conditions.
Officials have not announced a final explanation for how the parasite contaminated the lettuce.
Determining the precise contamination pathway could help prevent similar outbreaks in the future.
Consumers Cannot Detect Contamination by Sight
One of the most difficult aspects of the outbreak is that contaminated produce may look completely normal.
Consumers cannot reliably determine whether lettuce contains Cyclospora simply by examining it.
That places significant responsibility on agricultural producers, processors, distributors, restaurants and regulators to maintain food-safety controls throughout the supply chain.
The long journey from farm to supermarket or restaurant means contamination can potentially affect consumers in many different states.
The Outbreak Raises Broader Food-Safety Questions
The scale of the current outbreak has also triggered debate about the resilience of America’s food-safety surveillance system.
Experts have pointed to the complexity of coordinating federal, state and local health departments during large outbreaks.
The investigation demonstrates why rapid reporting, laboratory testing and cooperation between agencies are essential.
A delay at any stage can make it harder to identify contaminated products before they reach more consumers.
What Should People Do?
Consumers should follow current FDA and state health-department guidance concerning recalled products.
People who still have recalled iceberg lettuce should not eat it and should follow official instructions for disposal or return.
Anyone experiencing prolonged or severe gastrointestinal symptoms should contact a healthcare professional.
Because Cyclospora requires specific testing, patients should mention possible exposure to contaminated food or participation in a known outbreak when speaking with medical providers.
The Investigation Is Still Developing
Federal officials say the recalled lettuce associated with the specific multistate outbreak is believed to have been removed from the market.
However, investigations into other Cyclospora clusters are continuing.
The CDC also warns that its case figures are preliminary and can change as states submit additional information.
That means the final scale of the 2026 outbreak may not be known for some time.
A Major Test for the U.S. Food-Safety System
The 2026 Cyclospora outbreak demonstrates how quickly a microscopic parasite can become a nationwide public-health challenge when contaminated produce enters a complex distribution network.
The immediate priority is to identify remaining transmission sources, protect consumers and provide treatment for people who become ill.
The longer-term challenge is determining exactly where contamination occurred and strengthening safeguards so similar outbreaks can be detected and contained earlier.
For now, health authorities continue monitoring new cases while federal and Mexican investigators examine the lettuce supply chain.
With the outbreak already affecting communities across numerous states, the investigation remains one of the most significant food-safety efforts of the U.S. summer.
Note: Cyclospora surveillance numbers are updated regularly. Confirmed national cases and the separate lettuce-linked outbreak totals should not be treated as identical figures because the lettuce outbreak represents only a subset of all reported U.S. cyclosporiasis cases.
