CDC Investigates 7,400 Cyclospora Cases as Second Outbreak Cluster Emerges

The Centers for Disease Control and Prevention reported more than 4,100 laboratory-confirmed cases of cyclosporiasis across at least 34 states since May 1, 2026, with an additional 7,400 suspected illnesses under investigation. Officials said the outbreak has expanded rapidly this season, marking a record high for U.S. infections and prompting the identification of a second cluster linked to contaminated food sources.

Combined, these figures represent more than 11,000 reported illnesses this season, marking a record high for U.S. infections, according to CDC surveillance data and media reports from July 14. The agency noted that the current caseload includes both cluster-associated cases under Food and Drug Administration (FDA) traceback and sporadic cases without a known common source.

As of mid-July 2026, the Centers for Disease Control and Prevention (CDC) confirmed 4,173 laboratory‑confirmed, domestically acquired cases of cyclosporiasis across at least 34 states, with an additional 7,400 suspected illnesses under investigation, federal health officials said.

Among the outbreak investigations, a second cluster has been identified and linked to shredded iceberg lettuce served at Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio, and West Virginia. The CDC, FDA, and state health departments are actively investigating this multistate outbreak, which epidemiologic and traceback data indicate is connected to shredded iceberg lettuce from a single supplier in Mexico. Officials reported that 90% of interviewed patients in this cluster consumed iceberg lettuce in their meals. As of July 13, more than 400 Cyclospora infections in four states were linked to this source, with additional cases still under investigation. The CDC has advised consumers to avoid shredded iceberg lettuce from Mexico served at Taco Bell locations in the affected states while the FDA continues its traceback work.

Hospitalizations associated with cyclosporiasis have been reported but no deaths have occurred. Records show at least 308 hospitalizations linked to the current U.S. season, with some data sets indicating 141 hospitalizations among nearly 7,000 possible cases. Specifically, the Taco Bell outbreak has accounted for 94 hospitalizations among infected individuals who reported exposure at the chain’s locations in five states. Officials emphasized that, despite the “unusually high number” of cases, the illness is generally treatable with no fatalities confirmed to date.

The geographic spread of cases is broad, with reports placing confirmed infections in 34 to 41 states. CDC officials stressed that the current counts reflect a nationwide surveillance tally comprising multiple clusters and sporadic infections rather than a single unified outbreak. Michigan health authorities, for example, have interviewed more than 1,000 infected individuals, many of whom reported lettuce and salad greens as common exposures, though no specific brand or supplier has been definitively identified.

Cyclosporiasis is caused by the Cyclospora cayetanensis parasite, which is transmitted through food or water contaminated with fecal matter and is not typically spread from person to person, according to CDC information. Common symptoms include watery diarrhea, stomach cramps, nausea, loss of appetite, bloating, fatigue, and sometimes low-grade fever or flu-like symptoms. Without treatment, the illness can last from a few days to a month or longer and may be more severe in young children, older adults, and immunocompromised individuals. The CDC and other health authorities recommend specific antibiotics for treatment and stress the importance of adequate fluid intake to prevent dehydration. Officials also note that cooking is the only reliable method to kill the Cyclospora parasite on contaminated produce.

Public health guidance from the CDC includes washing hands with soap and water before and after handling produce, rinsing fruits and vegetables under clean running water, and scrubbing firm produce with a clean brush. Consumers are advised to buy whole heads of lettuce, remove outer leaves, thoroughly wash remaining leaves, and refrigerate cut or prepared produce within two hours. Amid ongoing investigations, the CDC cautioned against consuming shredded iceberg lettuce from Mexico served at Taco Bell locations in the five affected states.

The FDA’s traceback investigation is focused on the distribution pathways of shredded iceberg lettuce from Mexico to determine whether contaminated products may have reached locations beyond the initially identified states. Meanwhile, the broader multistate outbreak remains under investigation, with CDC officials stating on July 14 that no specific food source has yet been confirmed for cases outside the Taco Bell cluster. The agency continues to monitor the situation and update guidance as new information becomes available.