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Over the past week, the US recorded 766 new cases of cyclosporiasis, a smaller increase of 2.1% compared to the 2.7% increase the previous week. The number of new cases has decreased compared to the week prior for five weeks in a row. However, there have been seven separate Cyclospora outbreaks in the US since June, and four are still ongoing. The largest outbreak spans 17 states. In total, there have been more than 35,000 cases recorded across 48 states in 2026, a significant increase compared to the 4,000 cases reported in 2025.

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9/03/2026 — For the fifth week in a row, the number of reported cyclosporiasis cases — while still increasing — had a smaller increase than the week prior. This week, cases increased by 2.1% (+766 cases). This is lower than the 2.7% increase reported last week. The states still reporting cases are reporting fewer new cases per week; some states are not reporting, so the overall total may be higher. So far this year, the US has recorded more than 35,000 cases* across 48 states, significantly more than the nearly 4,000 cases reported in 2025.

*The cyclosporiasis data we report are tallied by the date the health department reported them and include confirmed and probable cases. All data are procured from state health department websites. Some health departments include cases for the entirety of 2026, while others include cases from May 1, 2026 to now.

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Michigan’s total number of cyclosporiasis cases increased by 233 cases over the past two weeks, for a total of 14,510 cases in 2026 so far. For context, the typical yearly average is usually between 40 and 50 cases a year. Although the cumulative case count increased this week, the number of new weekly cases has decreased for the past five weeks in a row. 

Ohio has the second-highest number of cases, with 6,063 total for 2026, and recorded 189 new cases over the past week. Similar to Michigan, although the number of cumulative cases is increasing, the number of new cases per week has been decreasing for the past four weeks. 

As the number of new cases per week slows, some states will stop updating their department of health websites with case count information. For example, South Carolina has stopped updating their total case count as of September 2, as the cyclosporiasis season in the state typically has ended at the end of August.

Click here to interact with the cyclosporiasis map on Datawrapper

Seven Cyclospora outbreaks have been under investigation so far this year by the US Food and Drug Administration (FDA), with one spanning 17 states, the largest currently under investigation. Three of those outbreaks have since ended, but all seven remain active investigations. Only one of those outbreaks — the large multistate outbreak — has been linked to any specific food product – iceberg lettuce –although the FDA investigation continues. The remaining six outbreaks have not yet had an identified food source.

According to a recent Politico report, three major federal Cyclospora research projects at the USDA’s Beltsville Agricultural Research Center (BARC) are ending or facing severe disruption following congressional budget cuts and facility relocations in the fall. While the USDA asserts that research has not been disrupted, concerns have been raised over a mandate limiting staff to sample preservation instead of new research, and the fact that all scientists assigned to the study have declined relocation. Public health experts, university researchers, and USDA staff cited in the article warn that losing BARC’s resources cuts off essential parasite samples, surrogates, and collaborative expertise, making it significantly harder to study the Cyclospora parasite and trace outbreak sources.