The 2026 cyclosporiasis season has moved faster than the federal numbers meant to track it. When I last wrote about this, Michigan had roughly 150 reported cases that the U.S. Centers for Disease Control and Prevention (CDC) had not yet folded into its national count. As of this weekend, that gap has widened into a chasm — and a second state has joined the picture.

Michigan’s count has now climbed to approximately 300 cases, according to the Michigan Department of Health and Human Services (MDHHS), up from the 170 cases the state reported on July 1. Michigan typically sees about 50 cases in an entire year. The state is careful to note that many of these are initial reports and it cannot yet say for certain that they are all part of the same outbreak — but the trajectory is unmistakable.

The genuinely new development is Ohio. The Ohio Department of Health reported at least 177 cases across 43 counties as of July 2, with 171 of them occurring in June — most since June 20 — concentrated in the northwest of the state near the Michigan line. A day later, a Ross County Health District update, flagged by the outbreak-surveillance platform BEACON, put the number of suspected Ohio cases higher still, at more than 268. The state describes much of this surge as suspected rather than laboratory-confirmed, and it should be read that way — but with the count climbing day to day, the volume and the timing are what matter.

A single state posting an unusual number of cases is a cluster. Two neighboring states surging at nearly the same time is the pattern that turns a “surveillance count” into a probable common source. BEACON, which is tracking this event, characterizes the near-simultaneous rise in Michigan and Ohio as the strongest signal so far this season of a potential multi-state outbreak — even though no epidemiologic link between the two has yet been confirmed, and no official conclusion has been reached that these clusters are one event. The two states have an established cross-border information-sharing group and are comparing cases directly.

The CDC’s most recent published data still cover illness onset from May 1 through June 16, 2026: 145 U.S.-acquired cases across 17 states, with 20 hospitalizations and no deaths. That count explicitly excludes the updated numbers from Michigan and Ohio. It also lags New York, which the CDC’s own map already flagged as the hardest-hit state and which has separately tracked around 107 cases since early May, according to local reports. Put those pieces together and the real-world floor is now on the order of 145 nationally, plus 300 in Michigan, plus somewhere between 177 and 268 in Ohio, plus roughly 107 in New York — well over 700 people — sitting behind a federal headline of 145.

This lag is not a mystery, and it is not a contradiction. It is a recognized feature of how federal aggregate reporting works: states investigate and count in real time, and CDC’s national numbers catch up on their own cadence. The lag should not be read as a sign that transmission has plateaued anywhere. It is exactly why I keep saying the state counts are the ones to watch right now.

No common food vehicle or exposure source has been confirmed. MDHHS, the Ohio Department of Health, the CDC, the FDA, and state and local health authorities are investigating in parallel. That work now includes genotyping of Cyclospora cayetanensis specimens to test whether the cases share a transmission cluster, along with traceback of implicated produce, detailed exposure histories, and review of travel and onset dates.

The absence of a recall does not mean the outbreak is over — and it does not mean investigators are asleep. Cyclospora is simply one of the hardest foodborne pathogens to trace. It contaminates produce at the farm or irrigation level rather than during processing, so the traceback chain is longer. It has an incubation period of one to two weeks, long enough that by the time a patient sees a doctor, they often cannot remember what they ate. And it resists the chlorine-based sanitizers routinely used in produce washing, which means contaminated product can move all the way to a store shelf or a restaurant kitchen despite standard cleaning steps.

Past U.S. outbreaks have repeatedly been tied to fresh produce — basil, cilantro, raspberries, snow peas, mesclun and bagged salad. Historically these were often imported items, though more recent investigations have also identified domestically grown produce as the source. Until investigators name a commodity, the safe assumption is that already-distributed product could keep generating new infections.

If you have watery diarrhea that will not quit — the hallmark is frequent, sometimes explosive bowel movements lasting more than a few days — see a doctor and ask specifically to be tested for Cyclospora. This matters because the parasite requires a specific laboratory test that is not part of a standard stool culture. It is routinely missed. It is treatable: the standard course is the oral antibiotic trimethoprim-sulfamethoxazole (TMP-SMX), sold as Bactrim or Septra, typically for ten days.

Washing produce is worth doing but understand its limits with this particular parasite — scrubbing and rinsing will not reliably remove Cyclospora, and neither will the sanitizer rinses used commercially. Cooking does destroy it. People who are immunocompromised, along with the very young and the elderly, are at higher risk of a severe course and should be especially cautious.