The number of confirmed cyclosporiasis cases in the United States has climbed to 17,180, according to the latest data from the Centers for Disease Control and Prevention (CDC), as health officials continue investigating multiple outbreaks of the foodborne illness. The latest figures, covering cases reported through August 24, represent an increase of 1,464 cases from the previous week.
- The CDC has recorded 17,180 confirmed U.S. cases of cyclosporiasis since May 1.
- Cases have been reported across 48 states and Washington, D.C.
- 922 people have been hospitalized and two deaths have been reported.
- At least 11,844 additional cases require further investigation or analysis.
- A major multistate outbreak has been linked to recalled iceberg lettuce.
- CDC and FDA officials are also investigating at least six other clusters whose sources have not been identified.
- Michigan remains the hardest-hit state, with 14,277 cases reported.
Cases Continue to Rise
The latest CDC figures show that the number of laboratory-confirmed infections continues to increase as health departments submit additional reports.
As of August 24, 17,180 people had been confirmed with cyclosporiasis acquired in the United States. That compares with 15,716 cases reported a week earlier, meaning the national total increased by nearly 1,500 cases in seven days.
The CDC cautions that the reported figure does not represent the full number of people who may have become infected. The agency says at least 11,844 additional cases may require further investigation to determine whether they meet the criteria for confirmed domestically acquired cyclosporiasis.
Recent infections can also take weeks to appear in national surveillance data because of the time required for diagnosis and reporting. The CDC estimates that there can be roughly a six-week gap between the onset of symptoms and the agency receiving a case report.
Michigan Accounts for Most Reported Cases
Michigan continues to account for the overwhelming majority of confirmed cases.
The state recorded 14,277 cases as of the latest reporting period, an increase of about 3% from the previous week. The slower rate of increase could indicate that transmission is beginning to decline, although health officials continue to monitor incoming reports.
Michigan had previously experienced much faster increases during the summer. Earlier in August, the state reported more than 13,900 cases, although officials cautioned that some of the increase reflected delays in laboratory processing rather than newly acquired infections.
Two deaths associated with the outbreak have also been reported in Michigan. Both individuals had significant underlying health conditions.
Lettuce Outbreak Remains Under Investigation
The CDC says its national case count includes infections connected to an ongoing multistate outbreak involving recalled iceberg lettuce.
The Food and Drug Administration previously linked that outbreak to shredded iceberg lettuce supplied by Taylor Farms from central Mexico and served at Taco Bell restaurants. The recall was expanded as investigators identified infections in additional states.
The CDC’s latest surveillance data now include cases associated with that outbreak alongside infections that have not been connected to a common source.
Health officials are continuing to investigate the lettuce-linked outbreak while monitoring other groups of infections across the country.
Officials Investigate Additional Clusters
The lettuce investigation is not the only source of concern.
The CDC and FDA are currently investigating at least six additional cyclosporiasis clusters for which the source has not been confirmed. This means the 17,180-case national total should not be interpreted as representing a single outbreak or a single contaminated food product.
Earlier CDC investigations also identified clusters in several states that were not immediately linked to the iceberg lettuce outbreak. Investigators have been collecting information about patients’ food exposures and other potential sources as they attempt to determine how the infections occurred.
One of the Largest U.S. Foodborne Illness Events
The scale of this year’s increase makes the 2026 cyclosporiasis season one of the largest recent foodborne illness events in the United States.
For comparison, the CDC recorded only 1,180 domestically acquired laboratory-confirmed cases between May 1 and August 31, 2025. This year’s total of 17,180 cases as of August 24 is therefore many times higher than the comparable figure from last year.
The CDC’s surveillance data also show that cases have been reported across almost the entire country, although the distribution varies substantially between states.
What Is Cyclosporiasis?
Cyclosporiasis is an intestinal infection caused by the microscopic parasite Cyclospora cayetanensis.
The illness commonly causes prolonged watery diarrhea and can also lead to abdominal cramps, nausea, fatigue, loss of appetite and weight loss. Symptoms can persist or return if the infection is not treated.
Cyclospora infections are typically associated with contaminated food or water. Fresh produce has been implicated in previous outbreaks, making food-safety investigations particularly important when clusters emerge.
The U.S. cyclosporiasis season generally runs from May through August, although infections can occur outside that period.
Health Officials Continue Monitoring the Outbreak
The CDC is updating its cyclosporiasis surveillance data weekly as states submit additional confirmed cases and investigators resolve cases that are still under review.
The agency currently reports 17,180 confirmed domestic cases, 922 hospitalizations and two deaths through August 24. Because additional cases remain under investigation and reporting can take several weeks, the national total could continue to change.
With multiple clusters still under investigation and the source of several infections unknown, federal and state health officials continue to work on identifying additional food or environmental exposures that could be contributing to the increase.
For now, the latest CDC figures show that the 2026 cyclosporiasis outbreak is continuing to affect communities across the United States, even as the rate of new cases appears to be slowing in Michigan, the country’s hardest-hit state.
The Cyclospora outbreak in the United States has surpassed 17,000 laboratory-confirmed cases, according to the latest CDC surveillance data. As of August 25, the CDC reported 17,180 confirmed domestically acquired cases, an increase of 1,464 from the previous week.
The Cyclospora surge has prompted health officials to investigate multiple clusters and possible food sources across the country.
Cyclospora Cases Continue to Rise
The CDC’s surveillance season began on May 1, 2026. The agency notes that recent Cyclospora illnesses may not yet appear in official totals because it can take approximately six weeks for case information to reach federal surveillance systems.
This reporting delay means the actual number of infections could be higher than the currently confirmed total.
Cyclospora Testing Challenges
Diagnosing Cyclospora can be challenging because the parasite requires specialized laboratory testing. Patients with prolonged or recurring diarrhea may need specific testing when healthcare providers suspect cyclosporiasis.
The CDC continues to provide laboratory and surveillance guidance to support identification of infections.
Cyclospora and Public Health Monitoring
The growing number of Cyclospora cases demonstrates the importance of coordinated surveillance between federal, state, and local health agencies. Monitoring helps investigators identify clusters and determine whether contaminated foods may have been distributed across state borders.
Cyclospora Prevention
Consumers can reduce the risk of Cyclospora and other foodborne illnesses by following food-safety practices, including washing produce appropriately, maintaining clean preparation areas, and following official recalls or public health advisories.
Because contamination may not always be visible, consumers should also pay attention to current food-safety warnings.
