A new multistate outbreak of cyclosporiasis is putting health officials on alert as cases of the foodborne illness continue to be investigated across the United States. The illness is caused by the microscopic parasite, which can contaminate fresh produce and cause days, or even weeks, of severe gastrointestinal illness.
Unlike many foodborne illnesses, cyclospora is most often linked to fresh fruits and vegetables that are eaten raw, including leafy greens, herbs and berries. Investigators are working to determine the exact source of the current outbreak while tracing where contaminated food may have been distributed.
California is not among the states that are experiencing an increase in cyclosporiasis cases, and there are no known local outbreaks in the state, Department of Public Health officials said. Locally speaking, there have been no confirmed cases in Shasta or Tehama counties either.
“In the two-and-a-half years that I have been public health officer … we have a couple of cases (of cyclosporiasis) a year. This is a GI (gastrointestinal) bug that we will see intermittently,” Tehama County Public Health Officer Dr. Timothy Peters said.
Although several states have reported illnesses tied to the current outbreak, public health officials say no California cases are currently known to be linked to outbreaks. Nonetheless, residents were encouraged to protect themselves by practicing safe food handling and thoroughly washing their produce.
Here’s everything to know about cyclosporiasis and how to avoid it.
What is cyclosporiasis?
Cyclosporiasis is an illness caused by a tiny, single-celled parasite called cyclospora cayetanensis, according to the U.S. Food and Drug Administration.
It is a protozoan parasite that is so small, it can only be seen with a microscope. It can infect humans when they eat food or drink water that’s been contaminated with fecal matter.
What foods can carry cyclosporiasis?
Fresh produce is the food most commonly linked to cyclosporiasis outbreaks. Foods associated with infections include bagged salad mixes, romaine lettuce, spinach, basil, cilantro, parsley, raspberries, blackberries, snow peas, sugar snap peas, and other fresh fruits and vegetables eaten raw. Contaminated water used to irrigate crops or wash produce is often the source of contamination, according to the FDA.
How to prepare food to avoid cyclosporiasis
The safest option is to cook leafy greens, cilantro, basil, green onions, snow peas and raspberries after carefully washing them under clean, running water. Heating food to 158 degrees or higher kills the parasite.
If you must eat raw, fresh produce, the Centers for Disease Control suggests:
What caused previous cyclosporiasis outbreaks?
In the past, outbreaks in the United States and Canada have been tied to bagged salad mixes and kits, such as pre-cut lettuce blends with romaine, iceberg, red cabbage and carrots; fresh cilantro, basil, raspberries, snow peas and green onions.
Among them were outbreaks identified:
How many cyclosporiasis cases in California?
To date in 2026, California has experienced fewer cases than in 2025. From January to June, 41 provisional cases of the gastrointestinal infection were confirmed in the state, compared to 80 cases during the same period in 2025. Annual averages from 2015 to 2025 are 106 cases.
“It’s important to understand that California experiences cases of cyclosporiasis every year, with a majority of cases acquired internationally,” said Dr. Erica Pan, California Department of Public Health (CDPH) Director and State Public Health Officer. “We are aware of the outbreaks affecting other states, however, and are closely monitoring for any signs of local acquired infection.”
The United States had recorded 1,645 infections, with 141 of those resulting in hospitalizations. No deaths were reported as of July 14.
The largest outbreaks have been reported in states such as Michigan, New York, Texas, Louisiana and Connecticut.
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This article originally appeared on Arizona Republic: Is cyclosporiasis in Northern CA? Food to avoid amid parasite outbreak
Reporting by Kristen Jordan Shamus, Tiffany Acosta, David Benda and Jenny Espino, Arizona Republic / Arizona Republic
USA TODAY Network via Reuters Connect
By Kristen Jordan Shamus, Tiffany Acosta, David Benda and Jenny Espino, Arizona Republic | USA TODAY Network
