Something is in the food.

Investigators have interviewed more than 1,000 people. They still don't know what you ate.

As of July 14, 2026, more than 6,700 Americans have been confirmed or are suspected to have contracted cyclosporiasis, a parasitic intestinal illness caused by a microscopic organism called Cyclospora cayetanensis. Cases have been reported in 34 states. At least 141 people have been hospitalized. The number of confirmed cases is already more than six times higher than it was at this point last year.

Federal and state health officials know the parasite came from food. They know it almost certainly came from fresh produce. They know Michigan and Ohio are at the center of a growing multistate outbreak that has now spread to West Virginia and Kentucky. They know lettuce or salad greens are a likely culprit.

What they don't know is where, exactly, it came from. No specific produce item has been recalled. No grower or supplier has been named. The investigation is ongoing.

This is what a foodborne illness outbreak looks like from the inside: not a clean recall and a tidy resolution, but a slow, painstaking process of interviewing sick people about everything they ate in the two weeks before symptoms appeared, cross-referencing purchase records, and waiting for a pattern to emerge. Meanwhile, people keep getting sick.

Gwen Biggerstaff, deputy director of the CDC's Division of Foodborne, Waterborne, and Environmental Diseases, told reporters at a July 14 press briefing that cyclospora investigations are "particularly challenging and take a significant amount of time and effort." The parasite does not spread person to person. It comes from something eaten, something that looked safe, something that looked fresh.

Most people who get sick never get counted.

Cyclospora is invisible to standard stool tests. When a patient walks into a clinic with watery diarrhea, fatigue, and cramping, the routine diagnostic panel that most labs run will not detect it. A clinician has to specifically request modified acid-fast staining or a PCR-based test to find Cyclospora oocysts in a stool sample. Many clinicians, particularly those who have never encountered a case, simply don't know to ask.

The result is a surveillance gap that the CDC acknowledges openly: the true number of people sick with cyclosporiasis in the United States right now is almost certainly far higher than what has been confirmed. Some people recover after weeks of illness and are never tested. Others are tested with the wrong method and told nothing is wrong. The waxing and waning symptom pattern, where patients feel briefly better before relapsing, makes it easy to mistake for a passing stomach bug.

Select a step below to trace the diagnostic pathway and see where it breaks down.

This gap matters for the outbreak investigation too. Every undiagnosed case is a missed interview, a missing data point, a food purchase that never gets traced. The more cases that slip through the diagnostic net, the harder it becomes to identify the contaminated source before more people get sick.

This is not the first time.

Fresh produce has been the source of every major U.S. cyclosporiasis outbreak on record. The parasite spreads when food or water is contaminated with human feces containing Cyclospora oocysts, most often through agricultural water used for irrigation or washing. It cannot be killed by the chlorine washes applied to most commercial produce. It survives in refrigerated environments. Cooking destroys it, but most of the produce it has been linked to is eaten raw.

The history of U.S. outbreaks is a roster of foods that sit at the center of American summer eating.

The pattern raises a harder question than which bag of lettuce: why does this keep happening, and what does it say about how fresh produce moves through the American food supply? Cyclospora oocysts do not spontaneously appear on produce. They get there through contaminated water, inadequate sanitation, or hygiene failures somewhere in the supply chain, often thousands of miles from the consumer who eventually gets sick.

The agency investigating this outbreak is not the same agency it was two years ago.

Since early 2025, the CDC has undergone the most significant workforce reductions in its history. In February 2025 alone, roughly 1,000 employees were terminated in a single day. By the end of 2025, approximately 3,000 people had left the agency, representing about one quarter of its total workforce. Staff across divisions focused on foodborne illness surveillance, outbreak response, and public health communications were among those cut or who took early retirement under pressure.

The 2026 cyclosporiasis outbreak is unfolding inside that diminished infrastructure. Gwen Biggerstaff, deputy director of the CDC's Division of Foodborne, Waterborne, and Environmental Diseases, acknowledged at a July 14 press briefing that cyclospora investigations are "particularly challenging and take a significant amount of time and effort." The investigation involves coordinating across dozens of state health departments, interviewing hundreds of sick people, and cross-referencing food purchase histories, work that requires experienced staff and intact institutional relationships.

Sarah Boim, a CDC communications staffer terminated in the February 2025 cuts, described the broader stakes in an interview with WABE, later reported by NPR. The harm, she said, would come to people who never knew what the CDC had been protecting them from. That harm is not hypothetical. It is countable, in cases and hospitalizations, in weeks of illness, in food that looked perfectly safe.

The investigation continues. The source of the Michigan and Ohio cluster has not been named. The number of cases will keep rising as the six-week reporting lag resolves. And somewhere in the American food supply, the contamination that started all of this may still be moving.