Cyclosporiasis is a gastrointestinal illness caused by the Cyclospora parasite.
"Currently, in the United States, we have an outbreak of Cyclospora that causes the intestinal illness," explains Gabriela M. Andujar Vazquez, MD, medical director of Infection Prevention at Dartmouth Health’s Dartmouth Hitchcock Medical Center (DHMC).
"Important to know is that it's not transmitted by person, person to person. It's really a foodborne illness that people normally get from eating contaminated fresh produce," she says.
Here’s what to know about the disease in the region and how to prevent infection.
What is cyclosporiasis?
Cyclosporiasis is a gastrointestinal illness caused by the foodborne parasite cyclospora. The disease is not fatal.
"Typically it’s seasonal, around the summertime.This year we are seeing a high number of cases compared to last year," says Andujar Vazquez.
Where has the disease so far spread and are there cases in New Hampshire and Vermont?
In late July, the U.S. Centers for Disease Control and Prevention (CDC) reported that health officials were investigating reported outbreaks related to iceberg lettuce in nine states.
The CDC also reported that they were looking into outbreaks and illnesses of cyclosporiasis nationally and that those were unrelated to the iceberg lettuce outbreaks.
At the state level, the Vermont Department of Health reported that there were no current outbreaks and that risks to Vermonters were low.
But as of July 28, 2026, New Hampshire’s Department of Health and Human Services (DHHS) reported that there were 33 people in the state with cyclosporiasis and that two had been hospitalized.
The DHHS said they would be updating the number of cases every Tuesday going forward on their web site
What are the symptoms of cyclosporiasis?
People infected with cyclospora may develop symptoms including:
- watery diarrhea
- loss of appetite
- weight loss
- stomach cramps
- nausea
- fatigue
- low-grade fever
"About a week after exposure, you may start feeling watery, explosive diarrhea, abdominal pain, nausea, and vomiting," says Andujar Vazquez.
How long do symptoms of cyclosporiasis last?
Symptoms typically begin within one week after consuming contaminated food, but it can be as long as two weeks or more before symptoms develop.
Most healthy people with normal immune function will eventually get better on their own without treatment.
What should I do if I experience symptoms?
If you are experiencing symptoms or suspect you have cyclosporiasis, contact your healthcare provider to discuss your symptoms.
Be specific about your symptoms and possible exposures, so you can get diagnosed and treated appropriately.
How can I avoid getting cyclosporiasis?
Transmission occurs through ingestion of contaminated food or water. Dartmouth Health encourages frequent and thorough handwashing with soap and water (or hand sanitizer when soap and water are not available) and thoroughly rinsing produce—especially lettuces, fresh herbs, broccoli and berries—before eating.
"No matter if there's an outbreak or not, we always emphasize making sure that you are washing your produce with clean running water. That running water is what mechanically gets the spores and other potential bugs or organisms out of that produce," says Andujar Vazquez.
