A parasite outbreak tied to lettuce served at Taco Bell and sold at grocery stores has now sickened more than 11,000 people across 20 states, with federal health officials saying the multistate cyclosporiasis outbreak is only slowly winding down.

The Centers for Disease Control and Prevention reported 11,458 confirmed cases, 495 hospitalizations and two deaths as of its latest update, with three states added to the outbreak's footprint in the most recent count. Both deaths occurred in Michigan. Investigators traced the source to iceberg lettuce supplied by Taylor Farms de México, after finding that roughly 90% of interviewed patients had eaten iceberg lettuce before falling ill.

Cyclosporiasis is caused by a microscopic parasite, Cyclospora cayetanensis, typically spread through produce contaminated with fecal matter during growing or processing. Symptoms include watery diarrhea, cramping, bloating, fatigue and low-grade fever, often lasting weeks without treatment and sometimes relapsing after apparent recovery.

Recall already in effect, but cases still climbing

Taylor Farms recalled all iceberg lettuce sourced from its central Mexico growing operations back in mid-July, and the CDC says product tied to the outbreak's relevant date codes should no longer be on shelves or served in restaurants. Even so, new illnesses continued to surface for weeks afterward, a common pattern with cyclosporiasis given its long incubation period, which can run one to two weeks before symptoms appear.

ROUGHLY 90% OF PATIENTS INTERVIEWED HAD EATEN ICEBERG LETTUCE BEFORE FALLING ILL

The FDA's traceback investigation, run alongside the CDC and state health departments, has focused on the supply chain feeding both fast-food chains and retail grocers, a scale that helps explain why the case count has climbed into five figures — among the larger foodborne outbreaks reported in the U.S. in recent years.

The CDC says it has now slowed the pace of its public updates as new case reports decline, a signal the outbreak may be nearing its tail end, though officials cautioned the investigation remains open. Anyone experiencing prolonged watery diarrhea after eating fast-food or store-bought salads in recent weeks is advised to contact a healthcare provider, since cyclosporiasis requires a specific antibiotic course and does not resolve with typical anti-diarrheal treatment.

Taylor Farms has not detailed what caused the contamination at its Mexico operations, and no additional recalls tied to the outbreak have been announced since July.