A woman walks into a clinic after two weeks of relentless watery diarrhea, sometimes hitting 20 episodes a day. She has lost weight and cannot hold down fluids. Her stool tests come back negative. Without a doctor specifically ordering it, the lab will never check for Cyclospora cayetanensis. She goes home still sick, possibly for weeks longer.
This scene plays out constantly because Cyclospora is invisible unless someone looks for it. Most routine stool tests do not include it. A clinician must suspect the parasite exists before the laboratory will search for it. You find it on purpose, or you do not find it at all.
Last year the federal government made finding it officially optional. On July 1, 2025, the CDC downgraded FoodNet, its active surveillance network running since 1995 with the FDA, USDA and 10 state health departments, removing mandatory tracking of Cyclospora along with five other pathogens. Of eight diseases the system was designed to monitor, six became optional. Only Salmonella and E coli stayed mandatory. The downgrade came with budget cuts and arrived with no public announcement, disclosed only when a journalist asked two months later.
This summer, cyclosporiasis swept through the US food supply at levels not seen in years. As of July 15, the CDC confirmed 1,645 domestically acquired cases across 34 states, with 141 hospitalizations. The agency acknowledged more than 5,100 additional cases awaiting analysis. Michigan alone reported more than 3,700 cases. A typical year brings 40 to 50 there. Investigators still cannot identify what source or sources caused the contamination.
Why surveillance matters more than treatment
Cyclospora does not spread from person to person. The parasite's oocysts must mature in the environment for days before becoming infectious. Every case traces back to contaminated food or water someone consumed. The incubation period runs roughly a week. By the time a patient feels sick enough to seek a test, the meal has blurred into weeks of eating, and the produce carrying the parasite has been consumed or shipped elsewhere.
Treatment works. The infected woman will recover. Nothing changes for the thousand others eating from the same contaminated batch. Stopping these outbreaks depends on identifying the source and removing it from the food supply, work that requires timely, consistent case counts. For Cyclospora, surveillance is not paperwork attached to medical care. Surveillance is the only treatment that matters.
The surveillance downgrade did not introduce Cyclospora into lettuce this summer. The parasite would have contaminated the food supply regardless of how closely the government was watching. FoodNet itself did not count cases in Michigan. The network operates at 10 sites covering roughly 16 percent of the country. Its role is to serve as the tool sensitive enough to signal the nation that something unusual is happening, measured against a consistent baseline.
The result speaks for itself. Through early July, the CDC's national count stood at 145 cases. By July 13, confirmed cases had jumped to 1,645, and one state was reporting more illness than the entire country had officially recorded just days earlier. A count that arrives after the contaminated food has been eaten can document an outbreak. It cannot stop one.
The CDC's official explanation deserves consideration. Funding has not kept pace with resources needed to maintain surveillance for all eight pathogens, the agency argues. The remaining pathogens remain trackable through other systems. A narrower focus lets staff concentrate on core work. Each claim stands on its own merits. But those other systems are slower and passive, and the current outbreak demonstrates what they produce during a fast-moving crisis.
The FoodNet downgrade was not an isolated housekeeping decision. More than 3,000 public health workers have left the CDC through firings, forced retirements and attrition, roughly a quarter of its workforce by the end of last year. Much of what the CDC does is push resources and expertise down to state and local departments that conduct interviews and food tracebacks. Those are the people who will solve this outbreak. The Trump administration has labeled the inherited CDC a bloated bureaucracy and promised to eliminate what it considers wasteful and duplicative. The redundancy eliminated here was the capacity to notice.
The repair is straightforward. Restore Cyclospora to mandatory active surveillance at FoodNet sites. Publish national counts weekly through summer. Rebuild the state and local teams who conduct interviews and trace sources. This capacity costs modestly compared to the illness and hospital admissions it prevents, and vastly less than an outbreak nobody can identify.
Surveillance is not clerical overhead. It is a country's promise to its citizens that it will notice when people begin getting sick. The promise is being withdrawn quietly, one pathogen at a time, and the government is testing the system on a parasite that rarely kills. The next organism to test this system may be far less forgiving.
Author James Rodriguez: "The government did not create this outbreak, but it made sure we could not respond to it in time."
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