{"id":92148,"date":"2026-07-24T11:28:01","date_gmt":"2026-07-24T17:28:01","guid":{"rendered":"https:\/\/www.uchealth.org\/today\/?p=92148"},"modified":"2026-07-24T11:28:01","modified_gmt":"2026-07-24T17:28:01","slug":"cyclospora-outbreak-what-to-know","status":"publish","type":"post","link":"https:\/\/www.uchealth.org\/today\/cyclospora-outbreak-what-to-know\/","title":{"rendered":"What to know about the cyclospora outbreak and contaminated produce"},"content":{"rendered":"
<\/div>
\"A
The U.S. is experiencing a record number of cases this summer of a foodborne illness called cyclosporiasis. Contaminated lettuce may be causing outbreaks that have led to terrible cases of diarrhea for those who have gotten sick. Food quality control is essential to preventing foodborne illnesses. But it’s also essential to carefully wash fresh produce before you eat it. Photo: Getty Images.<\/figcaption><\/figure>\n

A parasite called cyclospora is causing thousands of cases of explosive diarrhea across the U.S. this summer.<\/p>\n

And while it\u2019s horrible to be sick with cyclosporiasis \u2014 as the illness from cyclospora is called \u2014 medical experts say it\u2019s typical for foodborne illnesses to increase during the summer months. That\u2019s because many outbreaks of foodborne illnesses have come from contaminated produce.<\/p>\n

In the case of the cyclospora parasite, federal health officials suspect that contaminated iceberg lettuce might be the source of the illnesses, but investigators are still exploring causes. And federal investigators have linked past outbreaks of foodborne illnesses to other types of produce, including spinach, onions<\/a> and cantaloupe.<\/p>\n

Most people have never heard of cyclospora. And while the number of cyclosporiasis cases is setting records in some parts of the U.S. this year<\/a> \u2014 especially in Michigan<\/a>, Ohio and New York \u2014 other states including Colorado are seeing a typical number of cyclospora cases: just a couple hundred so far.<\/p>\n

Why are foodborne illnesses like cyclosporiasis more common in the summer<\/strong>?<\/h2>\n

Infectious disease experts say foodborne illnesses are as common in the summer months as respiratory illnesses \u2014 like flu and COVID-19 \u2014 are in the winter.<\/p>\n

That\u2019s because people tend to eat fresh produce that comes from outdoor sources where pathogens like cyclospora can contaminate fruits and vegetables. People also tend to eat raw produce rather than cooking it. That means it\u2019s vital to wash fruits and vegetables to avoid pathogens that can make us sick.<\/p>\n

To help you make sense of the news about cyclospora and other foodborne illnesses, we spoke with Lauren Bryan, infection program manager at UCHealth Yampa Valley Medical Center<\/a>.<\/p>\n

What is cyclospora?<\/strong><\/h2>\n

Cyclospora is a parasite that most people haven\u2019t heard of because it\u2019s not one of the most common foodborne illnesses that sickens people in the U.S.<\/p>\n

What are foodborne illnesses?<\/strong><\/h2>\n

Foodborne illnesses occur when harmful bacteria, viruses or parasites contaminate food or water through fecal-oral transmission. The sickness that then occurs is often referred to as food poisoning, the stomach flu, a stomach bug or a 24-hour gastrointestinal bug.

Learn more about the most common foodborne illnesses<\/a> and how to avoid them.<\/div>\n

In the case of cyclospora, the illness is caused by a parasite that can contaminate fresh produce or water through human fecal waste. Outbreaks often are linked to fruits and vegetables because contamination can happen at several points in the growing and distribution process.<\/p>\n

How worried should I be about cyclosporiasis?<\/strong><\/h2>\n

Bryan said people in Colorado don\u2019t need to worry too much yet about cyclosporiasis because the case numbers are not unusually high this summer in the Rocky Mountain region. But it\u2019s always wise to carefully wash your produce and to adopt safe food-handling practices so you don\u2019t get sick from any foodborne illnesses.<\/p>\n

\u201cHow much you worry about cyclospora depends on where you live,\u201d Bryan said. \u201cSome states are having large cyclosporiasis outbreaks this year, but when you look at the data, you need to keep in mind that these are raw numbers. We\u2019re not receiving case numbers per 100,000 people. So, when you hear about thousands of cases, that sounds like a lot, but it may not be a high percentage of people.<\/p>\n

\u201cIn Colorado, we\u2019re seeing the normal seasonal averages for cyclosporiasis,\u201d Bryan said.<\/p>\n

Colorado health officials have detected the following cyclosporiasis illnesses in 2026 as of July 23:<\/strong><\/h3>\n