The Centers for Disease Control (CDC) claims that there are 4,173 cases of cyclospora in the United States as of July 21, 2026. They do acknowledge that there are more than 7,400 additional cases that are not laboratory confirmed and “require further investigation.”
The agency is investigating “multiple” clusters of cyclospora cases, including one outbreak that is affecting Michigan, Indiana, Ohio, Kentucky, and West Virginia that is linked to iceberg lettuce. Overall, the states that have the most cases are Michigan, Ohio, Indiana, New York, and North Carolina, with Texas, Illinois, Kentucky, and Virginia not far behind. The CDC notes that there may be other cases in other states that have not yet been reported.
Of those cases, there have been 308 hospitalizations and no deaths. Sick people range in age from 2 to 95 years. Illness onset dates range from May 1, 2026 to July 16, 2026. No one has died.
There have been many difficulties in solving this outbreak. First, the Cyclospora oocyst is difficult to collect from food. In many cases, by the time someone eats the contaminated food, gets sick, sees a doctor, and is tested, weeks have elapsed and the food has been eaten or destroyed. Secondly, there is no whole genome sequencing (WGS) for the cyclospora oocyst, so the DNA can’t be mapped. That means scientists have a harder time tracking it.
Scientists use genetic testing, targeting specific markers on stool samples to group related cases. This helps assist in prioritizing traceback and collection of other epidemiological evidence.
There is another outbreak that has sickened people who traveled outside the United States before they got sick. Those people are grouped separately because cyclospora is found naturally in tropical regions of the globe. There are 767 sick in that outbreak, with 33 people hospitalized. Forty one states report these cases too.
To protect yourself and your family, see our article on “What Are the Methods That Don’t Destroy Cyclospora?“
