A widespread outbreak of cyclosporiasis linked to iceberg lettuce has expanded to four additional states, bringing the total number affected to at least nine, according to the Centers for Disease Control and Prevention (CDC). The latest states to report cases include Illinois, Kansas, Oklahoma, and Pennsylvania, joining Michigan, Ohio, Indiana, Kentucky, and West Virginia, which were previously part of the outbreak.
As of Thursday, at least 1,947 people have fallen ill, with 98 hospitalizations reported. The Food and Drug Administration (FDA) has traced the source of the outbreak to iceberg lettuce grown in central Mexico and supplied by Taylor Farms. On July 17, Taylor Farms initiated a recall of bagged iceberg lettuce distributed across 27 states, including those currently connected to the outbreak. The affected products were delivered to a range of retailers and food service providers such as Taco Bell and Walmart, though the company has yet to provide detailed information regarding specific products or precise points of sale.
This outbreak occurs amid ongoing federal investigations into other cyclosporiasis cases nationwide. On Thursday, the FDA announced a separate cluster of 72 cases with no identified source or location as of yet. Nationwide, the CDC is monitoring or investigating more than 11,500 cases of cyclosporiasis, a parasitic infection typically spread through food or water contaminated with human fecal matter.
Michigan has reported the highest number of cases, with 7,664 confirmed as of Thursday—a figure described by state Chief Medical Executive Dr. Natasha Bagdasarian as “likely an undercount.” Laboratories there have reported shortages of reagents needed for diagnostic testing, which may contribute to delays or incomplete case identification. Meanwhile, North Carolina health officials reported 561 cases on Tuesday, nearly doubling from the previous week. State investigators have not identified a definitive source but noted parsley, cilantro, berries, and romaine lettuce as frequently mentioned items during patient interviews. A spokesperson for North Carolina’s health department emphasized that the presence of these foods in patient histories does not establish causality and suggested berries are less likely the source.
This year marks the worst recorded season for cyclosporiasis in the United States, with case numbers surpassing the average annual total of about 2,800 cases observed since 2016. While infections typically rise during warmer months between May and August, this year’s outbreak has significantly exceeded those seasonal expectations.
Public health experts warn that the actual number of infections is probably much higher than reported counts, as many symptomatic individuals may not seek testing, and reporting delays can impact federal totals. State health department data aggregated by The New York Times indicated nearly 15,000 cases as of Friday, exceeding CDC figures.
State-level case counts continue to rise sharply. Ohio confirmed 2,576 cases on Thursday, more than doubling since mid-July, while Indiana reported 684 cases, triple the number recorded a week earlier.
The FDA cautioned on Friday that case numbers are expected to continue increasing despite the ongoing recall by Taylor Farms. Officials note that it can take up to six weeks to confirm whether individual cases are linked to the outbreak. Meanwhile, investigations continue to identify sources and contain the spread of cyclosporiasis in affected states.