With a stomach-turning illness wreaking havoc in 34 states across the U.S., Californians can breathe a sigh of relief for now, according to the state Department of Public Health.
“There are no known local outbreaks in the state, and no California cases are currently known to be linked to outbreaks affecting other states, which are under investigation by their respective state health departments, the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration,” the department announced in a July 14 press release.
Starting July 13, more than 1,600 lab-confirmed cases of intestinal illness cyclosporiasis were reported by 34 states. The culprit: a parasite called cyclospora that’s typically spread through food and water contaminated with human feces.
The CDC reported that people got sick after eating food in the U.S. and didn’t report any travel during the 14 days before they got sick.
Rick Rosen, San Luis Obispo County’s interim health officer, told New Times that year-to-date data as of the week of July 6 showed California reported 41 cases of cyclosporiasis. The state reported 80 cases during the same period in 2025, according to the California Department of Public Health.
“There have been sporadic cases in the county and the state but that hasn’t seemed to deviate from baseline cyclospora activity year to year for the state of California and locally,” he said.
The hardest hit states, Rosen said, are Michigan, Ohio, West Virginia, and Kentucky.
The source of the parasite contributing to the surge in illness remains unknown. While reasons could range from irrigation issues in farmlands to poor food handling and processing practices, Rosen recommended not resorting to snap judgements until the CDC collects more data.
“The CDC is still in a data-gathering space and is reaching out to local health departments like ours,” he said. “The state has a hypothesis generating questionnaire. If we’re notified of cases of cyclosporiasis in our jurisdiction, we complete that information with the help of the sick person. We share that with the state, and the state shares that with the CDC.”
Rosen added that people diagnosed with cyclosporiasis should expect calls from the county health department. They learn about cases through automated electronic lab reporting that logs results after testing people’s stool, since the typical symptom of cyclosporiasis is watery diarrhea.
Other symptoms include nausea, cramping, and bloating, and significant weight loss. Symptoms can arise within two days to two weeks of getting infected. Rosen urged the public to visit urgent care or their primary care doctor if they begin experiencing such conditions.
“Lots of cases can go undiagnosed and people may not pursue treatment,” he said. “Cyclosporiasis is easily treatable with commonly available antibiotics.”
The parasite is known to cling to fresh produce. Freezing fruits and vegetables may not be enough.
Rosen recommended commonsense practices like thoroughly washing produce, scrubbing them with a produce brush if they can handle it, and cutting off parts that appear bruised or damaged.
Fruits and vegetables are best stored in the refrigerator within two hours of cutting them. Hard-to-wash items like raspberries could be cooked to kill potential parasites.
Harvestly Executive Director Taryn Mohler encouraged people to shop local. The nonprofit Central Coast online marketplace receives produce from roughly 30 farms based in SLO County and parts of northern Santa Barbara County.
So far, she hasn’t received any calls for concern, and asked shoppers to contact local farmers directly through the harvestly.org website.
“We’re really fortunate at Harvestly because so many of our farmers are small,” Mohler said. “Our biggest priority is communicating with farmers and making sure they’re using safe practices. … It’s so much easier to call your farmer if you’re nervous about their practices.” ∆
This article appears in July 16-23, 2026.
