Last year, the federal government downgraded active surveillance for Cyclospora cayetanensis, a parasite that causes cyclosporiasis.
This summer, thousands of Americans are sick, and the outbreak is spreading through the food supply on a scale not seen in years.
As of July 15, the CDC confirmed 1,645 domestically acquired cases across 34 states, with 141 hospitalizations.
The agency is aware of more than 5,100 additional cases awaiting analysis.
Michigan alone reported over 3,700 cases, compared to a typical 40-50 cases in a normal year.
On July 1, 2025, the CDC downgraded FoodNet, its active surveillance network, making tracking of Cyclospora optional at its sites.
The change also affected listeria, campylobacter, shigella, vibrio, and yersinia. Only Salmonella and E.
coli remained mandatory. The downgrade came with budget cuts and no public announcement.
Cyclospora is difficult to detect. Routine stool tests often miss it, requiring clinicians to specifically request testing.
The parasite's biology complicates outbreak response: oocysts must mature in the environment before causing infection, and the incubation period is about a week.
By the time patients are tested, the contaminated food is often gone.
Effective treatment exists, but identifying the source is critical to stopping outbreaks. Surveillance is essential for that work.
The CDC's downgrade reduced the capacity to detect unusual patterns early. Through early July, the national tally held at 145 cases.
By July 13, it jumped to 1,645, with one state reporting more illness than the entire country had officially registered.
Official Rationale and Consequences
The CDC says funding has not kept pace with maintaining surveillance for all eight pathogens, and that other systems can track the remaining pathogens.
However, those systems are slower and passive, as demonstrated by the current outbreak.
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.
The Trump administration has described the department as bloated and promised to eliminate waste, but critics argue the cuts eliminated the capacity to notice outbreaks early.
Dr. Robert B.
Shpiner, a clinical professor of medicine at UCLA, wrote in a commentary that the institutional lesson is clear: what a health system does not measure can spread in plain sight.
He called for restoring Cyclospora to mandatory active surveillance, publishing weekly national counts during summer, and rebuilding state and local teams for interviewing and tracing.
Surveillance is not clerical overhead; it is a promise to citizens that the government will notice when they get sick.
The current outbreak shows the cost of withdrawing that promise.
