Somewhere north of 4,000 people are sick with Cyclospora this summer, and the agency that is supposed to track them says it can confirm 843. That is not a rounding error. That is the whole story.
State health departments, tallied by NBC News as of July 13, put the national count above 4,000 across more than 30 states. Michigan alone reports more than 2,600 cases — a state that in a normal year sees about 50. Ohio, New York, Illinois, and North Carolina are among the hardest hit. Meanwhile the CDC’s own surveillance page lists 843 laboratory-confirmed, domestically acquired cases in 31 states as of July 9, with 86 hospitalized, no deaths, and another 1,500-plus cases it says still require further analysis. The agency insists it has no evidence of a single, multistate outbreak tying these illnesses together.
There is a reason the federal number and the real number have come unmoored. On July 1, 2025, FoodNet — the CDC’s foodborne-illness surveillance backbone — made Cyclospora reporting optional, cutting the pathogens states are required to track down to two: Salmonella and Shiga toxin–producing E. coli. States like Michigan kept counting. Plenty didn’t. So when the biggest wave of this parasite in years arrived, the country’s early-warning system was running with the lights half off. Michigan has already flagged salad greens among the likely culprits; the CDC and FDA still say they can’t name a vehicle.
Which raises a fair question: how big is this, really, measured against the outbreaks we actually managed to count? Here is every prior U.S. Cyclospora outbreak that crossed 500 known sick — still a short list, ranked by size.
- 2019 — 2,408 sick — imported fresh basil, Mexico. The 2,408 domestically acquired, lab-confirmed casesreported to the CDC in 2019 were the largest peak-season total since Cyclospora became nationally notifiable in 1999. It carries an asterisk, though — and it’s the same asterisk hanging over 2026. Only about 10 percent of those cases were ever tied to the confirmed vehicle: fresh basil distributed by Siga Logistics de RL de CV of Morelos, Mexico, served through restaurants in Connecticut, Florida, Georgia, Iowa, Massachusetts, Minnesota, New York, Ohio, Rhode Island, South Carolina, and Wisconsin. The rest were scattered across smaller clusters that were never pinned to a food. Even our “biggest outbreak” was, for the most part, never traced to a source.
- 1996 — 1,465 sick — Guatemalan raspberries. The outbreak that put Cyclospora on the map in North America: 1,465 cases across 20 states, the District of Columbia, and two Canadian provinces, traced to fresh raspberries imported from Guatemala. It is the textbook example — literally, in the New England Journal of Medicine — of local clusters that turned out to be one continental outbreak, and a warning that a handful of sick people at a luncheon can be the visible edge of something enormous.
- 1997 — 1,012 sick — Guatemalan raspberries, again. The sequel arrived the very next spring: 1,012 cases in the U.S. and Canada, same vehicle, after the growers’ voluntary risk measures failed to hold. Guatemala eventually stopped exporting raspberries to the U.S. altogether — a reminder that when we chased this parasite hard enough, we could follow it all the way back to a farm.
- 2020 — 701 sick — Fresh Express bagged salad. 701 laboratory-confirmed cases across 14 states — iceberg lettuce, red cabbage, and carrots out of a Fresh Express plant in Streamwood, Illinois, with 38 hospitalized. Epidemiology and traceback nailed the vehicle. I know this one well: my firm represented about 100 of those families. And note the food category — a bagged salad, exactly what Michigan is warning about right now.
- 2013 — 631 sick — salad mix and cilantro, Mexico. The CDC counted 631 cases across 25 states and New York City and was candid that this was more than one outbreak: restaurant illnesses in Iowa and Nebraska traced to salad mix from Taylor Farms de Mexico in Guanajuato, and a wave of Texas cases traced to fresh cilantro from Puebla. One summer, two vehicles, one number.
- 2015 — 546 sick — cilantro from Puebla, Mexico. 546 cases across 31 states; the mid-summer snapshot that circulated at 495 climbed to 546 by the time the season closed. Clusters in Texas, Wisconsin, and Georgia were tied to Puebla cilantro — a source the FDA had already flagged in 2013 and 2014 and eventually put under import alert. The vehicle for the cases outside those clusters was never identified.
- 2018 — 511 sick — salad served at a fast-food chain. 511 cases across 16 states linked to salad mix distributed to McDonald’s restaurants across the Midwest — one of two outbreaks that summer, the other being 250 sick from prepackaged vegetable trays, which fell just short of this list.
Notice what that list is, and what it isn’t. Seven outbreaks in three decades cleared 500 counted cases, and four of the seven were leafy greens or herbs — bagged salad in 2020 and 2018, cilantro in 2015 and 2013 — with raspberries and basil sitting at the top. The 2026 outbreak has already blown past every one of them on the states’ own numbers, with Michigan pointing squarely at salad greens, and the federal government is telling you it sees 843 illnesses and no connection between them.Behind every one of those numbers is a person who spent weeks on the bathroom floor because of something a rinse under the tap was never going to fix. The parasite didn’t get harder to count this year. We decided to stop counting it.