Cyclospora outbreak: Midwest epicenter, over 11,000 cases across 46 states

The Midwest continues to be the focal point of a cyclosporiasis outbreak, a parasitic infection that can cause weeks of watery diarrhea.

Outbreak Expansion and Case Numbers

On Friday, the FDA and CDC reported that the outbreak, previously concentrated in five states with Michigan and Ohio as hotspots, now involves nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia.

According to Georgetown University's Health Security Operations Center, which tracks state and national-level data, at least 11,276 cases of cyclosporiasis had been reported across 46 states in 2026 as of July 21.

Conflicting Data Sources

Several factors are contributing to confusion in this outbreak, including:

• Differing state and federal case counts
• Discrepancies in how the FDA and Taylor Farms have shared information on the suspected source of infections

In contrast to Georgetown's count, the CDC reported in its July 15 cyclosporiasis update that it had confirmed 1,645 domestic cases and was aware of more than 5,100 additional cases requiring further analysis for confirmation. Some state health departments are tallying cases as part of the ongoing outbreak, while others include all cases reported in 2026 in their figures.

According to the CDC, the typical cyclospora season lasts until late August, and cases could continue to rise until then.

Regional Impact

The states with the most known cases include Michigan and Ohio. Overall, data indicates that the majority of cases have been identified in the Midwest and mid-Atlantic states.

Katelyn Jetelina, assistant professor adjunct of epidemiology at Yale School of Public Health, wrote in her July 21 public health newsletter, Your Local Epidemiologist, that several outbreaks are occurring simultaneously, including one suspected to be caused by cilantro in New York. She described the Midwest outbreak as "its own beast" that has not yet shown signs of slowing down.

Product Recall

On July 17, Taylor Farms voluntarily recalled iceberg lettuce sourced from central Mexico and distributed in the U.S. The company advised consumers who purchased iceberg lettuce distributed from June 29 through July 16 in the following states not to consume it and to discard it:

Alabama, Arkansas, Connecticut, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Missouri, Mississippi, North Carolina, New Hampshire, New Jersey, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and Wisconsin.

The FDA stated in an update to its website: "Do not eat recalled iceberg lettuce from Taylor Farms de Mexico. FDA's investigation is ongoing."

However, other food sources have not been ruled out.

Expert Analysis

Jetelina noted that iceberg lettuce was recalled in 27 states "due to a combination of the complexity of food distribution networks and continued uncertainty around where people are most impacted."

Addressing the question "When will this end?" Jetelina said: "No one knows. Either the contaminated food works its way out of circulation, or it takes a few weeks, the temperatures get cool, and the parasites no longer mature on produce (basically killing themselves off). It's hard to tell from the data alone if this outbreak is coming to a close given that it's significantly delayed."

How to Avoid Cyclospora

Cyclospora spreads through contaminated food and water. Symptoms—including watery diarrhea, nausea, and stomach cramps—can take up to two weeks to appear, making it difficult to trace back to a definitive source.

The parasite is resistant to disinfectants, and washing food does not guarantee its removal, as it is particularly adept at sticking to produce.

Health authorities recommend the following to definitively kill the parasite:

• Cook foods to at least 158 degrees Fahrenheit
• For those who are more risk-tolerant, buy whole heads of lettuce and peel back the outer layer of leaves rather than choosing pre-washed, bagged, or pre-mixed salads