Cyclosporiasis outbreak hits 31 states as federal officials track source

The Centers for Disease Control and Prevention reported that an intestinal illness caused by the parasite Cyclospora has spread across multiple states, with federal health authorities working to identify its source. As of the latest data, 843 cases of cyclosporiasis have been reported, though officials acknowledge the true number is likely higher due to underreporting and delays in case registration. The outbreak, which has been linked to fresh produce in past incidents, has prompted warnings from public health officials about food safety practices and the need for continued investigation.

The outbreak has shown significant regional variation. Michigan, for instance, reported 1,562 cases as of late June, far exceeding previous years’ totals. North Carolina has also seen a sharp rise, with at least 145 cases documented between May 1 and July 7, placing it among the states with the highest case counts. In contrast, New Hampshire’s Department of Health and Human Services noted only two confirmed cases in 2026, stating the state has not experienced the same surge as other regions. Officials in New Hampshire emphasized that cyclosporiasis cases there remain low, with annual averages typically ranging from 2 to 9 infections over the past five years.

Health authorities have highlighted the challenges of tracing the outbreak. Cyclospora infections often emerge in the spring and summer, but this year’s spike has been more pronounced than in previous seasons. The parasite spreads through contaminated food or water, with past outbreaks tied to raspberries, basil, lettuce, and other fresh produce. Investigators rely on interviews with affected individuals to identify potential sources, though symptoms can appear up to two weeks after exposure, complicating efforts to pinpoint contaminated products. “It’s difficult to recall exactly what someone ate during that window,” a CDC spokesperson said, noting the six-week lag between illness onset and reporting.

Public health officials have urged consumers to take precautions, such as thoroughly washing fresh fruits and vegetables and cooking produce to kill the parasite. While cooking is effective, many people consume raw greens, herbs, and berries, increasing their risk. In North Carolina, state health departments have emphasized the difficulty of preventing contamination, as Cyclospora can survive the journey from farms to tables without cooking. “Prevention is much more challenging with fresh produce,” a spokesperson for the North Carolina Department of Health and Human Services stated, adding that no single source has been identified for the current surge.

The CDC has not confirmed a multistate link for all cases, though some clusters, like those in Michigan, suggest localized outbreaks. The agency continues to monitor trends, with data showing 17 states reporting cases as of mid-July. Hospitalizations have been reported in at least 86 instances nationwide, though no deaths have been recorded. Treatment typically involves antibiotics, and officials advise seeking medical care for severe symptoms like dehydration or persistent diarrhea.

Despite ongoing efforts, the source of the outbreak remains unclear. Previous investigations have traced outbreaks to imported produce or contaminated water, but current findings have not yet identified a common origin. The CDC and state health departments are collaborating to analyze patterns, with some experts suggesting the surge may reflect broader changes in food distribution or environmental factors. As the season progresses, public health agencies warn that cases could continue to rise, urging vigilance in food safety practices and timely reporting of illnesses.