Key points
- This page shows cyclosporiasis surveillance data reported to CDC since the start of the cyclosporiasis season on May 1, 2026.
- Recent illnesses may not yet be reported due to the time it takes to identify and report Cyclospora cases. It can take about six weeks from the start of symptoms to when CDC receives the case information.
- The true number of people sick with cyclosporiasis is likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora.
- The U.S. cyclosporiasis season is May 1 through August 31. Since it can take about six weeks to receive reports of new cases, CDC expects to continue identifying and investigating additional cases beyond this date.
What to know about cyclosporiasis
Clusters of cyclosporiasis under investigation
CDC is investigating multiple clusters of cyclosporiasis, including the large multistate outbreak linked to processed iceberg lettuce from central Mexico. This multistate outbreak has contributed significantly to the increase in Cyclospora cases this year.
Additionally, CDC and FDA are investigating other clusters for which sources have not yet been confirmed. These clusters are listed on FDA's active investigation table. If sources are identified and there is public health action for consumers to take, CDC will issue outbreak notices for these clusters.
Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis. Most cases in the United States occur in spring and summer. Learn more about how CDC collects cyclosporiasis data and investigates outbreaks.
Cases acquired in the U.S.
Since May 1, 2026, CDC has received reports of 18,445 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.
These data include the cases reported in the ongoing multistate outbreak linked to iceberg lettuce. The data also include cases not linked to that outbreak. Multiple jurisdictions have reported an increase of cases compared with the same period in 2025.
May 1 - August 31, 2026:
2
49 plus the District of Columbia
57% female
43% male
These people became sick in the United States and did not report any international travel during the 14 days before they got sick.
State health departments may have more information about the situation in their jurisdictions. Additionally, states may report higher case counts than CDC because they may include cases that do not meet CDC's formal reporting criteria.
Notice
U.S. case locations
Since May 1, 2026, 18,445 people have been reported with laboratory-confirmed cyclosporiasis acquired in the United States. The map shows where these people live. Potential Cyclospora infections are typically investigated by the state or local health department where people live, even if they were exposed to the parasite in another state. Cyclosporiasis cases may not be limited to the locations of known cases. The true number of people sick with cyclosporiasis is likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora.
Note: Hover over the map to see the range of cyclosporiasis cases for each state.
These data include case data reported directly to the CDC Cyclospora program. Case counts may not match exactly with what is listed in the Nationally Notifiable Diseases Surveillance System tables. New York State includes case reports from New York City. In Pennsylvania, cases are reported voluntarily. Data are preliminary and subject to change. For questions related to the number of cases reported in each state, contact that state's health department.
U.S. cases by date symptoms started
The chart below, called an epi curve, shows laboratory-confirmed Cyclospora cases reported since May 1, 2026, that were acquired in the United States. Cases are shown by the date a person’s symptoms started.
Daily case counts are preliminary and subject to change. The true number of people sick with cyclosporiasis is likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora. In addition, recent illnesses may not yet be reported due to the time it takes to identify and report Cyclospora cases. It can take about six weeks from the start of symptoms to when CDC receives the case information.
How we use epi curves
An epi curve helps public health investigators monitor an outbreak and understand whether illnesses continue to occur or have stopped. This information can guide decisions about public health actions.
Cases acquired outside the U.S.
These cases are in addition to those acquired in the United States.
May 1 - August 31, 2026:
1,900
66
0
46 plus Puerto Rico
56% female
44% male
Median date symptoms started for cases
These people became sick after eating food or drinking water while they were traveling outside the United States during the 14 days before they got sick.
This page was last updated on this date. Updates may include minor edits, image changes, or other modifications to page content.
The information on this page was last reviewed by subject matter experts to ensure accuracy.