The Centers for Disease Control and Prevention is monitoring a rise in cyclosporiasis cases tied to international travel, according to newly updated surveillance data. As of July 13, 2026, an additional 440 cases were in people who ate or drank food or water that made them sick while they were traveling outside the United States during the 14 days before they got sick. These travel-associated cases were reported across 35 states, indicating the illness affected a wide geographic spread of returning American travelers rather than being concentrated in one region.
Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis, typically contracted through contaminated food or water. The CDC's data shows the illness affected people across a broad age range, with sick people ranging in age from 14 to 89 years, with a median age of 45, and 59% were female. Of the travel-linked cases with information available, 20 were hospitalized, though no deaths have been reported in connection with this round of infections.
The travel-associated cases come alongside a larger domestic outbreak, with 1,645 lab-confirmed cases reported in people who acquired cyclosporiasis within the United States as of the same date, spread across 34 states. The CDC has cautioned that the true scope of the outbreak may be larger than official counts suggest, noting that it is aware of more than 5,100 additional cases that require further analysis to confirm as domestically acquired infections, separate from the confirmed travel-linked tally.
Investigations into the specific sources behind the current wave of cases are ongoing, with health officials working alongside state partners to pinpoint contaminated food or water sources both domestically and in the destinations where travelers were exposed. The median illness onset date for travel-linked cases was June 9, 2026, placing the bulk of exposures during the early summer travel season, a period of historically high international travel volume for U.S. residents.
What this means for you
Travelers returning from international trips who develop persistent watery diarrhea, loss of appetite, weight loss, stomach cramps, bloating, increased fatigue, or low-grade fever in the weeks following travel should consider cyclosporiasis as a possible cause and seek medical evaluation, particularly if symptoms last more than a few days. Because the illness is linked to contaminated produce and water, travelers to regions with inconsistent food safety oversight should take standard precautions: drink bottled or properly treated water, avoid raw produce that cannot be peeled, and be cautious with pre-cut fruits and salads from unfamiliar vendors.
If you do fall ill after returning from a trip, it's worth mentioning your travel history explicitly to your healthcare provider, since cyclosporiasis symptoms can overlap with other gastrointestinal illnesses and specific stool testing is often needed to confirm the parasite as the cause. Symptom onset can be delayed by days to weeks after exposure, so connecting a stomach illness to a trip that occurred a month earlier isn't always obvious without a doctor prompting the travel-history question.
While cyclosporiasis is rarely fatal and most cases resolve with appropriate antibiotic treatment, the scale of this year's case counts—both domestic and travel-linked—suggests health officials are dealing with a more active outbreak season than in prior years. Travelers should treat basic food and water safety precautions as a standard part of trip preparation rather than an afterthought, especially heading into the peak of summer international travel.