Diarrhea-inducing parasite cases reported in WA amid US outbreak. What to know
An intestinal parasite found on raw produce has sickened people in more than 30 states, including Washington state.
Since May 1, a total of 1,645 cyclosporiasis infections have been reported in the United States, resulting in 141 hospitalizations, according to the U.S. Centers for Disease Control and Prevention.
That includes more than two dozen cases in Washington state.
What are common signs of cyclosporiasis? How can you protect yourself and your family from foodborne illness?
Here’s what to know:
What is cyclosporiasis?
“Cyclosporiasis is a gastrointestinal disease caused by the microscopic parasite Cyclospora,” the CDC said.
Cyclosporiasis is contracted after consuming foods or water contaminated by the microscopic parasite, according to the U.S. Food and Drug Administration.
“Case counts typically rise during spring and summer months,” the CDC said, noting that May 1 to Aug. 31 is considered the annual cyclosporiasis season.
What are symptoms of cyclosporiasis?
The Cyclospora parasite causes “watery, and sometimes explosive, diarrhea and other stomach problems,” according to the Cleveland Clinic.
Other common symptoms include:
- Loss of appetite
- Bloating, including burping and farting
- Extreme tiredness (fatigue)
- Low-grade fever
- Stomach cramps
- Nausea
- Vomiting
Cyclosporiasis cases reported in Washington state
As of Tuesday, July 14, cyclosporiasis cases had been reported in a total of 34 states since May 1, according to the CDC.
That includes a ”large multistate outbreak” spread across at least four Midwestern states: Michigan, Ohio, West Virginia and Kentucky.
Based on past trends, the CDC expects cases to continue to rise.
Since May 1, Washington state has reported a total of 27 provisional cases of cyclosporiasis, according to Mark Johnson, public information officer for the Washington State Department of Health.
Of those, 22 cases involved international travel to an endemic area, Johnson said, while three cases were “acquired domestically.”
There were two cases where “international travel status is unknown,” according to state health officials.
“None of these cases are associated with outbreaks in other states,” Johnson wrote in an email to McClatchy Media. “Washington state does not have a cyclosporiasis outbreak.”
As of Tuesday, there had been no confirmed hospitalizations in Washington state due to cyclosporiasis, Johnson said, and no deaths linked to the parasitic infections.
Are there any cases in Pierce County?
As of early July, one cyclosporiasis case had been reported in Pierce County, The News Tribune previously reported.
“We have had one case of cyclosporiasis in Pierce County this year, reported on July 1 and associated with international travel,” Tacoma-Pierce County Health Department media representative Kenny Via told The News Tribune.
According to the state Health Department, zero to 11 cyclosporiasis cases are typically reported each year, “mainly after international travel.”
Which foods are linked to outbreaks?
The CDC said previous outbreaks have been “linked to consuming contaminated fresh produce.”
McClatchy Media reported Michigan health officials, which are at the center of the largest outbreak cluster, have identified the source of the cyclosporiasis in their state. New data and investigations have led to leafy greens as the most consistent exposure among affected individuals.
Eating fresh, imported produce can increase your risk of infection, according to the Cleveland Clinic.
The following foods have been tied to past cyclosporiasis outbreaks:
- Basil
- Bagged salads and salad mixes
- Cilantro
- Mesclun lettuce
- Parsley
- Raspberries
- Snow peas
- Sweet peas
How can I prevent cyclosporiasis?
“The best way to prevent cyclosporiasis is to avoid food or water that may be contaminated with feces,” or, poop, the CDC said.
In general, the Washington State Department of Health said you should “wash all produce, especially if it is to be eaten raw.”
“Fruits and vegetables should be washed by rinsing well in running cold water and scrubbing, instead of by soaking in standing water,” state health officials said.
Scrub tough-skinned produce such as cantaloupe with a brush or cloth.
“Although it’s unknown exactly how food and water become infected with Cyclospora, people should be aware that rinsing or washing food is not likely to remove it,” the U.S. Food and Drug Administration said.
Rather than purchasing pre-packaged or bagged salads, the Cleveland Clinic recommends opting for whole heads of greens, discarding the outer layers and washing the inner leaves individually.
This story was originally published July 14, 2026 at 6:00 PM with the headline "Diarrhea-inducing parasite cases reported in WA amid US outbreak. What to know."