Six weeks into a confirmed outbreak spanning 34 states, the U.S. Food and Drug Administration is still investigating "multiple produce items" as potential vehicles for Cyclospora cayetanensis — a microscopic intestinal parasite that causes prolonged, relapsing diarrheal illness and is not killed by standard washing. As of mid-July, the Centers for Disease Control and Prevention had confirmed 1,645 cases and 141 hospitalizations. No deaths have been reported. No single food source has been publicly named. Consumers have been given no actionable guidance about what not to buy.

That is the official posture. Here is what it means in practice: for roughly six weeks, Americans have been getting sick from something they ate, and the agencies charged with food safety have been unable — or unwilling — to tell them what it is. The FDA has confirmed lettuce is among the items under scrutiny, but the investigation encompasses a wider field of produce, and the agency has declined to specify further. In the interim, people keep eating. Cases keep rising.

Cyclosporiasis is not a new threat. The parasite has caused notable U.S. outbreaks linked to imported fresh herbs, raspberries, and leafy greens going back to the 1990s. In virtually every prior outbreak, the contamination traced back to agricultural water sources in countries with limited sanitation infrastructure — fecally contaminated irrigation water being the primary transmission mechanism. The parasite's oocysts are remarkably resilient: chlorine at standard treatment levels does not reliably inactivate them, and they are too small to be filtered out by conventional produce washing.

What makes this outbreak unusual is scale and pace. The 1,645 confirmed cases almost certainly undercount the true burden significantly — Cyclospora infection is frequently misdiagnosed because its symptoms mimic other gastrointestinal illnesses, the specific lab test required is not part of routine stool workups, and many people with mild-to-moderate illness never seek medical care. Epidemiologists typically apply substantial multipliers when projecting true outbreak size from confirmed case counts. The hospitalization figure of 141 suggests a meaningful share of confirmed patients experienced severe enough illness to require inpatient care.

Particularly alarming for public health messaging: cyclosporiasis does not behave like standard food poisoning. Symptoms — which include watery, often explosive diarrhea, significant fatigue, nausea, and loss of appetite — typically begin one to two weeks after exposure, meaning the connection to a specific meal or ingredient is rarely obvious to the patient. Crucially, the illness is known to relapse weeks after apparent recovery, even without re-exposure. Health departments in New York City have been specifically warning residents about this relapse pattern as case counts in the city continue climbing.

The geographic spread — now confirmed across 34 states, with North Carolina alone reporting over 300 cases — points toward a nationally distributed supply chain source rather than a regional or local one. That framing matters because it shifts the probable origin of contamination upstream: toward a large-scale grower, distributor, or import pathway rather than a local farm or restaurant. The FDA's mandate covers imported produce under the Foreign Supplier Verification Program, a regulatory framework that critics have long argued is under-resourced relative to the volume of produce entering the U.S. market annually.

There is a recurring pattern in large U.S. foodborne illness investigations: the longer the source identification takes, the more likely the implicated product has already moved through the supply chain and been consumed. By the time a recall is issued, the exposure window is often closed — which is cold comfort to anyone who was sick but resolves one of the political pressures on regulators. The absence of a named source to date may reflect genuine investigative complexity. It may also reflect the institutional caution that comes with publicly implicating a major commodity before evidence is airtight. Both things can be simultaneously true.

What the public is owed — and is not currently receiving — is a clearer interim communication framework. When an outbreak of this size has no confirmed source after six weeks, the FDA and CDC have an obligation to communicate the uncertainty explicitly, tell consumers what produce categories carry elevated risk based on the investigation's current direction, and explain what "multiple produce items" actually means in terms of shopping decisions. Telling people to wash their produce more carefully is inadequate guidance when the pathogen in question is not reliably removed by washing. The gap between what the agencies know and what they are saying is where people get hurt.