Colorado public health officials stated that they have recorded 90 local cases of a parasite so far this year.
The gastrointestinal illness called cyclosporiasis is caused by a microscopic parasite transmitting via contaminated food.
However, cyclosporiasis is not considered a fatal disease, though US officials are currently trying to find the reason behind this spike in cases nationwide.
What is the threat level of Cyclosporiasis in Colorado?
Colorado has yet to detect any outbreaks cyclospora linked to exposures in state, public health and environment spokesperson Hope Shuler said in a statement.
In 2026, nearly 90 cases were reported in Colorado from the start of January till June 30.
Cases tend to increase between May and August, Shuler added.
In 2025, there were 204 cases reported in the state, per the reportable disease dashboard.
Yes, but: It's unclear how many counties are currently impacted.
The state public health department saw a sharp decline to provide Axios with that data.
The data remain preliminary until next spring, at which point the state releases a breakdown by county, as per Shuler.
Cases are currently found "throughout Colorado, with more cases in more populous counties," Shuler added.
What you need to know about Cyclosporiasis?
Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis that causes an infection in the small intestine.
The disease is diagnosed by testing a stool sample.
Cyclosporiasis symptoms
Cyclosporiasis symptoms include "explosive" or "watery" diarrhea, and can last for a few days to more than a month without treatment, the CDC says.
