A parasite that causes prolonged and often severe stomach illness is spreading across the United States this summer, and New York has emerged as the hardest-hit state in the outbreak. Federal health authorities say cyclosporiasis, the intestinal infection caused by the microscopic Cyclospora parasite, has sickened at least 145 people across 17 states, and the caseload in New York outpaces that of anywhere else in the country. For residents across the New York area heading outdoors and gathering over the holiday weekend, the outbreak has become an unwelcome public health concern layered on top of an already sweltering few days.
According to the Centers for Disease Control and Prevention, the confirmed cases involve people who became ill between the beginning of May and the middle of June, and the agency is continuing to track new reports as they come in. Of the 145 people for whom detailed information was available, 20 required hospitalization, an indication of how debilitating the illness can be even though it is rarely fatal. Reassuringly, no deaths have been linked to the outbreak so far, but health officials caution that the numbers are likely to keep climbing as more cases are confirmed and reported through the surveillance system.
Cyclosporiasis is not a household name, but its symptoms are hard to ignore. The illness typically brings on watery diarrhea that can be frequent and, as health officials bluntly describe it, sometimes explosive, along with stomach cramps, nausea, loss of appetite, fatigue and a general sense of gastrointestinal misery. The symptoms can persist for weeks and may come and go, sometimes leading people to assume they are simply battling a stubborn stomach bug when in fact a parasite is to blame. Because the illness can drag on, doctors urge anyone with lingering diarrhea to seek medical care.
The parasite behind the outbreak is spread not from person to person but through food or water contaminated with the microscopic organism. In past outbreaks, Cyclospora has been traced to fresh produce, including items such as leafy greens, herbs and berries, and investigators strongly suspect a foodborne source is driving the current wave of illness. Only a small fraction of those infected reported traveling outside the country before becoming sick, which points health officials toward something being consumed domestically rather than an infection picked up abroad.
Despite the intensive investigation, the specific food responsible has not yet been pinned down. The CDC has noted that there is not currently evidence tying every case to a single, common source, meaning the outbreak may involve more than one contaminated product or supply chain. That uncertainty makes the parasite particularly frustrating to combat, because until investigators can identify and remove the contaminated item from store shelves and restaurant kitchens, the risk of additional infections remains. Tracing foodborne parasites can take weeks of painstaking work comparing what patients ate before they fell ill.
One of the reasons Cyclospora is so difficult to guard against is that it does not wash away easily. Health experts warn that the parasite can resist the kind of routine rinsing that many people rely on to clean fruits and vegetables, so a quick pass under the tap may not be enough to eliminate the danger. That resilience underscores why officials are focused on finding the source rather than simply advising consumers to wash their produce, and it explains how contaminated items can slip into the food supply and sicken people spread across many different states.
For now, health officials are advising New Yorkers and others to be alert to the symptoms, to see a doctor if they develop persistent or severe diarrhea, and to be aware that the illness is treatable with specific antibiotics once it is properly diagnosed. As the CDC and state health departments work to trace the outbreak to its source, the surge of cases serves as a reminder that foodborne illness can strike well beyond the usual summer stomach bugs. With New York at the center of the national tally, local residents in particular have reason to pay close attention as the investigation unfolds.