Foodborne Parasite Cyclospora Sickens Thousands Across U.S.
Editor's note: This story has been edited to include the latest outbreak updates, listed chronologically at the bottom of the article. Alternatively, you can read the most recent coverage here.
Cases of cyclosporiasis are surging across the U.S. this summer, with federal and state public health officials together reporting more than 700 cases of Cyclospora cayetanensis infection since May 2026.
Past foodborne cyclosporiasis outbreaks reported in North America have been linked to produce items including bagged salad mixes and kits, fresh herbs, raspberries, snow peas, and green onions.
Michigan Reports 572 Cases in Addition to CDC’s 145
The Michigan Department of Health (MDOH) alone has reported 572 cyclosporiasis cases within the state since late June, with counties in Southeast Michigan the most affected. For comparison, in a typical year, Michigan reports approximately 50 Cyclospora infections.
According to the latest figures (current through June 16) from the U.S. Centers for Disease Control and Prevention (CDC), an additional 145 cases of cyclosporiasis have been reported in 17 states—not including Michigan—since May 1. These cases have not yet been associated as part of a larger outbreak by CDC. Investigations to identify potential clusters and potential sources of illness are ongoing.
The Growing Prevalence of Cyclospora
Since the 1990s, the prevalence of Cyclospora cayetanensis has had an upward trajectory, trending toward possible endemicity. As explained by expert Larry Keener, CFS, PA in Food Safety Magazine, domestic cases of Cyclospora infections more than doubled from 537 in 2016 to 1,194 in 2017, and then nearly tripled to 3,519 cases in 2018. Between 2019 and 2022, the number of laboratory-confirmed cases of cyclosporiasis in the U.S. ranged from a high in 2019 of 2,408 cases to a low in 2021 of 1,024 cases. By 2023, there were nearly 3,000 cases of cyclosporiasis reported in the U.S.
Cyclosporiasis is now considered an "important neglected parasitic infection" by CDC. It is also a nationally notifiable disease.
Looking for quick answers on food safety topics?
Try Ask FSM, our new smart AI search tool.
Ask FSM →
Update, July 8, 2026: According to a CDC email uncovered by CNN, federal officials have been investigating several clusters of cyclosporiasis in Illinois, New York City, New York State, Pennsylvania, and Texas, which have suspected links to Mexican-style restaurants, a grocery chain, and a catered event. Additional cyclosporiasis clusters have been identified in Alabama, Kentucky, Michigan, Ohio, Tennessee, Virginia, and West Virginia. Investigations are ongoing with patient interviews underway.
At the state level, the number of Michigan cases is reportedly up to 681 since June 22. Ohio has also reported 177 cyclosporiasis cases since the beginning of the year, with 171 occurring in June alone, mostly since June 20. New York State (outside of New York City) has seen 112 cases in 2026, with 107 reported since May 1.
Meanwhile, FDA's Coordinated Outbreak Response and Evaluation (CORE) network is conducting traceback investigations on white and green onions, cucumbers, and cilantro to narrow down the list of potential transmission vehicles. Today, the agency added two Cyclospora outbreak investigations (one with seven cases and one with 18 cases) to its CORE table. Neither has been linked to a food source yet.
Update, July 10, 2026: MDOH has reported 1,251 cases of cyclosporiasis since June 22, resulting in 44 known hospitalizations. Monroe, Wayne, and Washtenaw counties (in the southeastern part of the state) are the most affected, with 215, 160, and 159 cases, respectively.
CDC has still not updated the publicly available data on national cyclosporiasis incidence.
Update, July 14, 2026: Per CDC, 843 domestically acquired cyclosporiasis cases have been confirmed in 31 states, plus another 1,500 pending analysis. Michigan alone has reported more than 2,600 cases and has flagged lettuce as a food item of interest in the investigation.
One year ago, CDC cut C. cayetenensis from its Foodborne Diseases Active Surveillance Network (FoodNet) last year.
Update, July 15, 2026: CDC has issued a health advisory warning the public of the increase in domestically acquired cyclosporiasis cases reported across the U.S., including a large outbreak cluster in the Midwest. Since May 1, 2026, CDC has received reports of 1,645 laboratory-confirmed domestically acquired Cyclospora cayetenensis infections spanning 34 states, with more than 5,100 additional cases requiring analysis. At least 400 cases in Michigan, Ohio, West Virginia, and Kentucky appear to be epidemiologically linked.
As of July 14, MDOH has reported more than 3,300 cases in the state alone. Read more.
Update, July 16, 2026: As of today, MDOH reports 4,312 cases resulting in 102 hospitalizations.
Update, July 17, 2026: FDA announced an outbreak cluster including 1,644 people across Indiana, Kentucky, Michigan, Ohio, and West Virginia. Shredded iceberg lettuce served at Taco Bell locations and sourced from a single Mexican supplier has been identified as the vehicle of infection. Read more.
Update, July 20, 2026: Taylor Farms of Mexico has been officially named as the supplier of implicated iceberg lettuce products to firms like Taco Bell and Walmart. Michigan is now reporting more than 5,000 cyclosporiasis infections in the state since June. Read more.
Update, July 21, 2026: As of July 20, Michigan reports 6,571 cyclosporiasis infections and Northwest Ohio has seen 2,029 cases. Read more.
Update, July 23, 2026: CDC has reported 4,173 laboratory-confirmed, domestic cases of cyclosporiasis connected to the five-state outbreak, with an additional 7,400 cases under investigation. Michigan is now reporting 7,171 cases.
FDA has added a new Cyclospora outbreak of 72 cases to its CORE Investigation table.
Several senators have written letters to U.S. Health Secretary Kennedy urging Cyclospora surveillance to be restored to the FoodNet program. Experts say that FoodNet cuts, although problematic, did not cause the current outbreak. Read more.
Update, July 24, 2026: The outbreak linked to Taylor Farms iceberg lettuce has been expanded to nine states. More than 1,900 people infected with Cyclospora have reported exposure to Taco Bell, and there have been at least 98 hospitalizations. Michigan and Northwestern Ohio report 7,664 and 2,380 cases, respectively.
FDA is currently investigating three other cyclosporiasis outbreaks aside from the nine-state cluster, comprising eight, ten, 18, and 72 cases. A food vehicle of infection has not yet been identified in any of these outbreaks. Read more.
Update, August 5, 2026: CDC has updated its total laboratory-confirmed case count of cyclosporiasis in the U.S. to 10,468 illnesses and 517 hospitalizations, as of August 3. CDC has also updated the number of states reporting cases to 47. The agency noted on August 4 that an additional 12,255 cases require further analysis and have not yet been laboratory confirmed or determined to be part of the U.S. domestic outbreak.
Additionally, CDC has expanded its list of states specifically associated with the Taylor Farms iceberg lettuce outbreak to 15, up from nine, and is reporting 6,358 illnesses, 278 hospitalizations, and two deaths associated with this outbreak. Affected states now include Arkansas, Iowa, Nebraska, New Hampshire, North Carolina, Missouri, Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia.
Update, August 12, 2026: CDC has updated its total laboratory-confirmed case count of cyclosporiasis in the U.S. to 13,895 illnesses, 740 hospitalizations, and two deaths in 47 states. CDC is aware of at least 10,455 additional cases of cyclosporiasis that are not laboratory-confirmed or require further investigation to determine whether they were somestically acquired. Many of the additional cases continue to be reported by Michigan, which, as of August 6, reports 12,485 cases and 279 hospitalizations.
Update, August 13, 2026: According to FDA, the number of cyclosporiasis cases linked to Taylor Farms lettuce is 9,481 in 17 states. Since the last update, two additional states have been added: Maine and Massachusetts.
FDA has also initiated an onsite inspection and sampling at Taylor Farms of Mexico in coordination with Mexican officials. The agency says it "remains confident that all recalled iceberg lettuce related to this specific Cyclospora outbreak is off the market."Update, August 20, 2026: Since May 1, 2026, CDC has received reports of 15,716 laboratory-confirmed cases of cyclosporiasis acquired in the United States. For comparison, 1,180 cases were reported in the United States between May 1 and August 31, 2025. At least 11,841 additional cases of cyclosporiasis may require further investigation and analysis. The Taylor Farms lettuce outbreak has contributed significantly to the increase of Cyclospora cases in 2026, but CDC has not updated its official outbreak-specific case count since August 13.
Update, August 21, 2026: The total case count associated with the multistate lettuce outbreak is now 10,930 illnesses reported from 17 states.
