A parasite that causes severe gastrointestinal illness, commonly known as cyclosporiasis, has been detected in California amid a growing outbreak across the United States. Health officials in California estimate that the state's recorded cases are only a portion of the total infections, as many individuals may recover without seeking medical attention or being tested.
The California Department of Public Health has recorded 41 provisional cases of cyclosporiasis in 2026. A majority of these infections in the state have been linked to international travel, rather than the expanding multistate outbreak.
Nationwide, at least 2,944 individuals in 32 states have been affected. Michigan has been particularly impacted, reporting 1,562 infections, which is approximately 31 times the usual annual average, and resulting in at least 44 hospitalizations. Investigators are exploring potential links to contaminated food but have not yet identified a specific source.
Cyclospora, the parasite responsible for cyclosporiasis, is typically transmitted through food or water contaminated with feces. Past outbreaks have been associated with imported fresh produce such as raspberries, basil, snow peas, mesclun lettuce, and cilantro. Symptoms can include watery diarrhea, nausea, vomiting, abdominal pain, bloating, fatigue, loss of appetite, and weight loss. The onset of symptoms usually occurs about a week after infection, but can range from two days to two weeks, complicating efforts to pinpoint the source of exposure.
The Centers for Disease Control and Prevention (CDC) recommends treatment with the antibiotic trimethoprim-sulfamethoxazole. In response to the rise in cases, some Taco Bell locations have temporarily removed ingredients like lettuce and pico de gallo from their menus as a precautionary measure, displaying notices citing a nationwide recall. However, neither the CDC nor the Food and Drug Administration has officially linked Taco Bell to any reported illnesses related to this outbreak.