Federal and state health authorities are continuing to investigate the largest known outbreak of cyclosporiasis in U.S. history, which has now expanded to 15 states and involves more than 22,000 confirmed and suspected cases. The outbreak, linked to contaminated iceberg lettuce sourced from central Mexico and supplied by Taylor Farms de Mexico, has resulted in the first two confirmed deaths ever recorded in a U.S. cyclosporiasis outbreak. Public health officials are urging consumers, restaurants, and retailers to remain alert as the investigation continues and additional cases are expected to be reported.
Outbreak Scope and Case Counts
As of August 4, 2026, the Centers for Disease Control and Prevention had expanded the outbreak to include six additional states: Arkansas, Iowa, Missouri, Nebraska, New Hampshire, and North Carolina. These states join Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia, which were previously identified as part of the outbreak. The total number of affected states now stands at 15, though health officials note that cases have been reported in several other jurisdictions that are not yet officially part of this outbreak investigation.
The cumulative patient count across the 15 affected states stands at 21,393 cases when combining confirmed and suspected infections. Michigan remains the epicenter of the outbreak, with 11,508 reported cases, including the two fatalities. Wayne County, which includes Detroit, has reported the highest number of cases within Michigan, with 1,379 confirmed infections. Washtenaw County has also been heavily affected, with more than 900 cases reported.
The CDC’s official figures are lower than state-level reporting: 10,468 laboratory-confirmed cases nationwide with an additional 12,255 suspected cases awaiting confirmation. However, health officials acknowledge that these numbers likely represent only a fraction of the total outbreak, as many individuals with mild symptoms do not seek medical care, and many cases are not properly diagnosed due to the difficulty of detecting Cyclospora. The CDC estimates that for every confirmed case, there may be several additional unreported infections, meaning the true burden of illness could be substantially higher.
To date, 47 states have reported cyclosporiasis cases across multiple separate outbreaks in 2026, with at least 517 people requiring hospitalization. The 2026 case count is already four times higher than the total recorded in 2025, making this year exceptionally severe for foodborne parasitic illness in the United States. The CDC is currently investigating at least five distinct cyclosporiasis outbreaks concurrently, with the 15-state outbreak representing the largest and most widespread of these investigations.
First Confirmed Deaths
On August 3, the Michigan Department of Health and Human Services reported that two Michigan residents had died from cyclosporiasis. These are the first deaths ever confirmed in a U.S. outbreak of the intestinal parasite. Previously, Cyclospora infections were considered rarely fatal, and the CDC had not documented any outbreak-related deaths in its surveillance history.
Both individuals had significant underlying health conditions that may have been compounded by the infection and related dehydration. The state health department declined to release further details about the two cases, citing privacy concerns. Both patients became ill before the FDA announced a voluntary recall of iceberg lettuce on July 17, indicating that the contaminated product had already been widely distributed and consumed before any public health intervention occurred.
Quoted in an article on thehill.com, Dr. Joel Kammeyer, division chief of infectious diseases at Wayne State University and the Detroit Medical Center, said that most patients recover readily with appropriate antibiotic treatment. However, patients with pre-existing conditions may not be able to withstand the severe dehydration that can accompany prolonged diarrhea, particularly if they are unable to maintain oral fluid intake or if they have compromised renal or cardiac function. The deaths have prompted state health officials to reiterate their recommendations for vulnerable populations to seek medical attention promptly if they develop gastrointestinal symptoms.
Epidemiological Investigation
The Food and Drug Administration has linked the outbreak to iceberg lettuce sourced from central Mexico and supplied by Taylor Farms de Mexico. The lettuce was served at Taco Bell locations in multiple states, as well as at other restaurants and in grocery store salad mixes. An FDA investigation identified the contaminated lettuce as the source of the outbreak through a combination of epidemiological interviews and traceback investigations, though authorities continue to investigate other potential sources and distribution channels.
The epidemiological link was first established in Michigan, where health officials conducted interviews with patients and found a consistent connection to iceberg lettuce from Taylor Farms served on Taco Bell menu items. Taco Bell immediately stopped using lettuce from Taylor Farms and transitioned to alternative suppliers. The company has cooperated with federal investigators throughout the process.
Traceback investigations have been complicated by the complex supply chain for fresh produce. Iceberg lettuce grown in central Mexico is harvested, packed, and shipped to multiple distribution centers across the United States, where it is further processed into shredded products and salad mixes. Identifying the specific lot or field of origin has required extensive coordination between U.S. and Mexican authorities, as well as collaboration with Taylor Farms and its suppliers.
Product Recall
On July 17, 2026, Taylor Farms de Mexico announced a voluntary recall of all iceberg lettuce sourced from central Mexico. The recall covered 25 shredded lettuce and salad mix products sold under eight different brand codes, distributed to foodservice customers in 27 states and grocery stores in 15 states. The recall is among the largest fresh produce recalls in U.S. history in terms of geographic scope.
Recalled products included Marketside-brand items sold at Walmart, described as “Iceberg Salad 12-oz or 24-oz” and “Shredded Lettuce 8-oz or 16-oz” with “Best if Used By” dates ranging from July 18 to August 3, 2026. The recalled iceberg lettuce products were distributed from June 29 through July 16 in 27 states. Retail store distribution of Marketside-brand products occurred at select Walmart locations in 15 states. Additionally, the recall included bulk shredded iceberg lettuce sold to restaurants, institutional foodservices, and other commercial customers under Taylor Farms’ foodservice labels.
Taylor Farms has stated that it has voluntarily suspended all iceberg lettuce sourcing and production from central Mexico for the remainder of the growing season. The company has commissioned independent experts to conduct a top-to-bottom review of food safety processes at its central Mexico facility, where production has been temporarily suspended. Taylor Farms reports investing more than $200 million annually in food safety protocols, including testing, sanitation, and employee training. The company has emphasized its commitment to identifying the root cause of the contamination and implementing corrective measures.
False Positive Test Result
The investigation has been complicated by a false positive test result that initially appeared to confirm the presence of Cyclospora in a Taylor Farms lettuce sample. On July 18, the FDA reported that a Taylor Farms lettuce sample had tested positive for the parasite. The following day, the agency stated that the test “should be considered a false positive” after further analysis revealed that the initial result could not be replicated. As of July 19, the FDA confirmed that there were no confirmed positive sample results for product testing for Cyclospora. Taylor Farms subsequently stated that the FDA had apologized for the error.
The false positive did not change the company’s recall decision, and Taylor Farms continues to cooperate with federal investigators. The FDA has maintained that “overwhelming epidemiological evidence” points to the shipment of shredded lettuce from Taylor Farms de Mexico as the source of the outbreak, despite the lack of positive product samples. The false positive has raised questions about the reliability of testing methods for Cyclospora, which is notoriously difficult to detect in environmental and food samples due to its low concentration and the need for specialized laboratory techniques.
Symptoms and At-Risk Populations
Cyclospora cayetanensis is a microscopic parasite transmitted via the fecal-oral route, most commonly through consumption of contaminated food or water. The parasite is notoriously difficult to detect because it does not multiply in food and requires specific laboratory methods for identification. Symptoms typically begin about one week after infection and include diarrhea, loss of appetite, bloating, extreme fatigue, low-grade fever, stomach cramps, nausea, and vomiting. The diarrhea is often explosive and can occur up to 20 times per day, leading to significant fluid and electrolyte loss.
If untreated, symptoms can last from a few days to a month or longer. Symptoms may appear to resolve and then return one or more times, creating a relapsing pattern that complicates diagnosis and treatment. In immunocompetent individuals, the illness is generally self-limiting but can be prolonged and debilitating. The treatment of choice is a course of antibiotics, specifically trimethoprim-sulfamethoxazole, which is effective in most cases. However, proper diagnosis requires a stool sample tested for Cyclospora oocysts, which may not be routinely performed in all clinical laboratories.
In Michigan, adults aged 30 to 39 have been the hardest-hit demographic, accounting for 2,216 reported cases. This age group is often in the prime of working life, and the illness has resulted in significant productivity losses, absenteeism, and healthcare utilization. Children under the age of 10 and adults over 65 have also been affected, though their case counts are lower relative to the population size.
While cyclosporiasis is rarely life-threatening, children, older adults, and immunocompromised individuals are at increased risk of serious illness. Immunocompromised persons may experience more severe illness of longer duration along with complications requiring close medical attention. Dehydration resulting from severe diarrhea is the primary mechanism by which the infection can become dangerous for vulnerable patients, potentially leading to acute kidney injury, electrolyte imbalances, and in severe cases, organ failure.
Investigation Challenges
The ongoing investigation faces several significant challenges that have hampered efforts to identify the precise source and prevent additional cases. The parasite is difficult to detect in product samples, as demonstrated by the false positive test result and the inability to obtain positive confirmatory tests from any product samples to date. The lack of positive product samples means that investigators must rely on epidemiological data, which is less definitive than direct microbiological confirmation.
Additionally, federal agencies have experienced staffing reductions that may affect outbreak response capacity. The FDA is slated to lose 3,500 workers, about 19% of its staff, while the CDC faces cuts of 2,400 workers, or roughly 18%. The CDC has already lost nearly 3,000 jobs since January 2025, including positions in the Division of Foodborne, Waterborne, and Environmental Diseases. Former FDA Commissioner Scott Gottlieb has stated that weather conditions may have raised the risk of contamination in central Mexico, with raw sewage potentially reaching farmed areas through flooding or a breach in sanitation infrastructure. “There was some event that happened in central Mexico, we don’t know what yet,” he told CNBC. “That led to a lot of fields probably getting contaminated“.
Democratic Congressman Josh Gottheimer has attributed the lack of surveillance to staffing cuts at the FDA and CDC, stating that the CDC had fired more than 70% of the team responsible for tracking Cyclospora and other parasites since 2025. These cuts have slowed the pace of investigation and limited the capacity of agencies to conduct field investigations, laboratory testing, and data analysis.
The Food Traceability Rule, which would have required enhanced recordkeeping for certain high-risk foods, has been delayed from 2026 to 2028, further complicating efforts to trace contaminated produce through the supply chain. The Food Emergency Response Network program was also suspended after key scientists were fired, reducing the surge capacity for testing during large outbreaks.
Impact on Food Service Industry
The outbreak has affected consumer confidence in restaurant lettuce products. Data indicates lower lettuce sales and reduced visits to restaurant chains such as Sweetgreen and Chipotle, which use shredded iceberg lettuce in many menu items. Taco Bell has reported a decline in sales at affected locations, though the company has not released specific figures. Some retailers have stopped sourcing produce from central Mexico entirely, opting for domestic or other international suppliers.
Taylor Farms, as one of the largest fresh produce suppliers in North America, has faced reputational damage and potential legal liability. At least 13 lawsuits have been filed against Taco Bell and Taylor Farms by affected individuals seeking compensation for medical expenses, lost wages, and pain and suffering. Legal experts anticipate that the number of lawsuits will grow as more cases are confirmed and more individuals come forward.
The economic impact extends to Mexican growers, who have lost a significant portion of their export market for iceberg lettuce during the peak summer season. The suspension of sourcing from central Mexico has disrupted supply chains and forced growers to destroy crops that could not be sold. The Mexican government has expressed concern about the economic consequences and has offered to cooperate with U.S. authorities in the investigation.
Broader Context
The 2026 outbreak far surpasses previous U.S. cyclosporiasis records. The prior record of approximately 4,700 cases was set in 2019, when multiple outbreaks were linked to various produce items including basil and cilantro. Taylor Farms was also linked to a 2013 Cyclospora outbreak that spread across multiple states and infected hundreds of people, underscoring the company’s recurring role in such incidents.
Cyclospora has been recognized as an emerging pathogen in the United States since the 1990s, when outbreaks were linked to imported raspberries from Guatemala. Despite improvements in food safety regulation and industry practices, the parasite continues to cause sporadic outbreaks, and climate change may be expanding its geographic range. Warmer temperatures and altered rainfall patterns can favor the survival and transmission of the parasite in agricultural environments.
The CDC is currently investigating at least five separate cyclosporiasis outbreaks, with additional cases linked to unidentified sources. The 15-state outbreak represents the largest of these investigations, and health officials warn that the true scope may not be known for several months due to delays in case reporting and laboratory confirmation.
Public Health Recommendations
The FDA advises consumers, restaurants, and retailers who purchased or received recalled iceberg lettuce distributed by Taylor Fresh Foods to discard it immediately. Consumers who have purchased recalled products are eligible for full refunds at the point of purchase. Individuals experiencing symptoms consistent with cyclosporiasis are advised to contact their physician. The infection is treatable with antibiotics, though proper diagnosis requires a stool test for Cyclospora, which may not be routinely performed.
Public health officials recommend that anyone who has consumed shredded iceberg lettuce from affected sources in the past month and develops watery diarrhea, fatigue, or abdominal cramps seek medical evaluation. Healthcare providers are encouraged to consider cyclosporiasis in patients with persistent diarrheal illness, especially those with travel history to affected areas or consumption of lettuce from known contaminated sources.
Consumers are advised to practice good food hygiene, though washing produce is not sufficient to remove Cyclospora because the parasite lives within plant tissues and cannot be rinsed away. Cooking produce is effective but is not practical for salads. The only reliable prevention is to avoid consuming contaminated produce, which requires effective surveillance and recall systems.
