Federal and state health officials are investigating a multi-state outbreak of cyclosporiasis that has sickened more than 1,600 people nationwide, including in Pennsylvania.
Advertisements
The Centers for Disease Control and Prevention reported that as of July 13, 2026, there have been 1,645 laboratory-confirmed since May 1. The agency is tracking an additional 5,100 cases that require further analysis.
The CDC reported 11 to 30 cases in Pennsylvania, but noted cases are only reported voluntarily in the state.
“The true number of people sick with cyclosporiasis was likely higher than the number reported,” the CDC said. “This is because some people recover without medical care and are not tested for Cyclospora.”
Advertisements
The Pennsylvania Department of Health and health officials in multiple other jurisdictions have noted a spike in infections compared to the same time frame in 2025.
Because there is an estimated six-week lag between when a person falls ill and when the case is reported to federal databases, health officials expect the total case count to rise.
Advertisements
Cyclosporiasis is a non-life-threatening gastrointestinal disease caused by Cyclospora, a microscopic parasite that infects the small intestine.
The illness is often transmitted when people ingest food or water contaminated with infected feces.
According to public health data, U.S. outbreaks are frequently linked to imported or domestic fresh produce, including salad mixes, berries, cilantro, basil, green onions, and snow peas.
Advertisements
While a definitive source for the current outbreak has not yet been established by federal investigators, regional patterns are beginning to emerge. The Michigan Department of Health and Human Services announced Monday that preliminary data points toward lettuce or salad greens as a potential source, but they cautioned that other foods remain under consideration.
Officials have not yet identified a specific grower, supplier, or type of produce.
Advertisements
Patients range in age from 2 to 95, with a median age of 44. Women account for 56 percent of the cases.
Of those infected, 141 individuals have been hospitalized.
No deaths have been reported.
Advertisements
The Pennsylvania Department of Health said that symptoms of the illness usually manifest about one week after exposure, but the window can span from two days to two weeks. Common signs of infection include watery or explosive diarrhea, stomach cramps, bloating, nausea, fatigue, appetite loss, and weight loss.
Diagnosing the infection requires identifying the parasite in stool samples, a process state health officials warn can be difficult. Patients may need to submit multiple samples over several days before the parasite is successfully detected.
Advertisements
Most people with healthy immune systems will recover from cyclosporiasis without medical intervention, but an untreated illness can persist for anywhere from a few days to a month or longer, officials said.
As a way to reduce the risk of infection, health departments are advising citizens to thoroughly rinse all fruits, vegetables, and herbs under running water, scrub firm produce like melons with a clean brush, and keep cut or cooked produce refrigerated within two hours. Cooking food thoroughly also effectively kills the parasite.
