Sixteen hundred Americans have contracted cyclosporiasis since May, six times last year's count for the same period, with federal health officials linking over 400 infections to shredded iceberg lettuce served at Taco Bell locations across five states (CDC outbreak investigation).

The outbreak has hospitalized 141 people. That's 9% of confirmed cases. No deaths have been reported. Michigan alone has logged 7,171 cases, more than four times the entire national confirmed count, because the state includes probable cases still under investigation (Michigan Department of Health and Human Services).

Taylor Farms de Mexico voluntarily recalled all iceberg lettuce sourced from central Mexico on July 17, pulling product distributed between June 29 and July 16 across 27 states (Taylor Farms recall notice). The FDA's traceback investigation identified the supplier after analyzing meal data from 190 Michigan cases: 90% reported eating iceberg lettuce at Taco Bell before falling ill (FDA outbreak investigation).

A sample tested positive for Cyclospora on July 18. The FDA retracted the result two days later, calling it a false positive. The agency maintained its focus on Taylor Farms lettuce based on epidemiological evidence, but the reversal left the investigation without a confirmed laboratory sample linking the parasite to the suspected source (PBS NewsHour).

Cyclospora cayetanensis, a microscopic parasite that causes watery diarrhea, bloating, and fatigue, spreads through food or water contaminated with feces from infected people. The organism requires seven to fifteen days to mature in the environment before it becomes infectious. Person-to-person transmission doesn't happen, but the two-week incubation window makes outbreak tracing difficult (CDC Health Alert Network).

Clinicians must specifically request Cyclospora testing—routine stool tests miss it. Symptoms typically begin about a week after exposure and can last a month or longer without treatment, sometimes disappearing and returning in what the CDC calls a "remitting-relapsing course."

The FDA is investigating four other cyclosporiasis clusters beyond the Taco Bell cases, though three are now considered resolved. Rutgers microbiologist Donald Schaffner told NPR that "these are often separate and unrelated clusters," which suggests the outbreak may be more complex than a single contaminated lettuce source (NPR).

Taco Bell locations saw an 18.9% decline in foot traffic after federal officials named the chain in the investigation. Taylor Farms has stopped sourcing iceberg lettuce from central Mexico for the remainder of the growing season and dispatched investigators to examine potential contamination sources at the farm. No Taylor Farms branded products were involved in the recall, only lettuce supplied to food service operations. The implicated farm represents less than 1% of U.S. iceberg lettuce supply.

Case counts typically peak during spring and summer months, when the CDC designates May 1 through August 31 as cyclosporiasis season. The 1,645 confirmed cases reported through mid-July compare to just 249 at the same point in 2025. The jump has no confirmed explanation: no identified change in growing practices, inspection protocols, or environmental conditions.