Travel warning as stomach parasite spreads to 18 states

Follow us on Google

Travelers across the United States are being urged to take extra precautions with fresh produce and drinking water as health agencies investigate at least 145 cases of a foodborne parasite that causes severe stomach illness in people in 18 states.

Parasite-linked illness triggers renewed summer travel concern

Publicly available surveillance updates describe an early summer spike in cyclosporiasis, an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. A July summary of national data indicates that 145 laboratory-confirmed infections were recorded between May 1 and mid-June in people who acquired the illness within the United States, with reports now extending across 18 states as case investigations continue.

Cyclosporiasis has appeared repeatedly in recent summers, but analysts note that the pace of reporting this season is faster than in many recent years. Some states, including Michigan, Ohio, Colorado, Louisiana and Texas, are documenting higher-than-expected case numbers, prompting local advisories that coincide with the peak U.S. vacation period.

While current national tallies remain relatively modest compared with large outbreaks in past decades, coverage in outlets such as the Associated Press, Axios and regional broadcasters highlights that numbers in several states are already surpassing their usual annual totals. Experts caution that formal counts likely underestimate the true burden, because confirming cyclosporiasis requires specific stool testing that is not always ordered for routine gastrointestinal complaints.

For travelers, the timing of the uptick is particularly significant. Many of the affected states are popular destinations for summer road trips, national park visits and city breaks, raising the chances that visitors could be exposed through restaurant meals, catered events or grocery purchases away from home.

What cyclosporiasis is and how it spreads

Cyclosporiasis is an intestinal infection that typically causes profuse watery diarrhea, cramping, bloating, nausea, loss of appetite and fatigue. According to educational materials from the Centers for Disease Control and Prevention, symptoms usually start about one week after exposure but can appear anywhere from two days to two weeks later. Without treatment, illness may last several weeks or longer, with symptoms that can come and go.

The parasite is spread when microscopic oocysts from human feces contaminate food or water and are then ingested. Fresh herbs, leafy greens, salad mixes and berries have all been implicated in prior U.S. outbreaks. The organism needs time in the environment to become infectious, so standard person-to-person transmission, such as caring for a sick family member, is not considered the primary route.

Most healthy people recover fully with appropriate antibiotic treatment and supportive care, but the infection can lead to dehydration and weight loss, especially if diarrhea is prolonged. Hospitalizations have been reported this season, although current summaries describe no associated deaths.

Because the parasite is not killed reliably by common chemical disinfectants and may resist simple rinsing, completely eliminating risk from fresh produce is difficult. Nevertheless, food safety guidance continues to emphasize careful washing of fruits and vegetables, particularly items eaten raw, as a practical way to reduce the amount of contamination that might be present.

States affected and what surveillance reports show

Detailed breakdowns of the national case count show that, between May 1 and June 16, at least 145 domestically acquired infections were attributed to residents of 17 states. These included Alaska, Colorado, Connecticut, Florida, Georgia, Illinois, Louisiana, Massachusetts, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, Virginia and Wisconsin. Subsequent media summaries describe additional activity that brings the total number of affected states to at least 18 as new reports are added.

At the same time, Michigan is documenting a separate, unusually large outbreak that began in late June. State updates and independent coverage describe hundreds of confirmed cases there alone, largely in the southeastern part of the state. Those infections are generally being tracked outside the initial 145-case national cluster, underscoring how quickly localized problems can expand once a contaminated food item enters regional distribution.

Regional outlets in Colorado, Louisiana, Ohio, Virginia and Texas are likewise reporting rising numbers of cyclosporiasis diagnoses this summer. Some states characterize their situation as a seasonal increase within expected patterns, while others note that current totals already exceed their typical yearlong counts. The absence of a single identified food source at the national level suggests that more than one contaminated product or supply chain may be involved.

Federal summaries consistently stress that there is, at this stage, no clear evidence linking all reports to one nationwide outbreak. Investigators instead describe multiple clusters that appear to be under active review, with attention on where patients shopped, dined or attended events in the weeks before becoming ill.

Why the surge matters for summer travelers

Cyclosporiasis historically peaks in late spring and summer, a period that overlaps closely with domestic vacation and business travel. People often eat more salads and fresh fruit in warm weather, dine outdoors, and rely more heavily on restaurant and convenience foods during trips, all of which increase potential exposure to contaminated produce.

Travelers may also be less likely to seek medical care promptly if they attribute diarrhea and fatigue to routine travel stress or minor food upset. Because the illness can last for weeks without treatment, visitors might only develop more severe symptoms after returning home, complicating efforts to trace infections back to a particular state or food item.

For those planning travel through the affected regions, the current situation does not mean trips must be canceled. However, it does call for heightened attention to basic food and water precautions. Public-facing guidance encourages travelers to be especially cautious with fresh, uncooked produce and to pay attention to any health advisories that might be issued at their destination.

People with weakened immune systems, older adults and those with underlying health conditions may wish to discuss travel plans with a healthcare provider, particularly if they anticipate eating a large amount of raw produce in settings where food sources are difficult to verify.

Practical steps to reduce risk on the road

Health education resources recommend several common-sense measures travelers can take to reduce, though not entirely eliminate, their chances of encountering Cyclospora. These include thoroughly rinsing fruits and vegetables under running water, removing visibly damaged or bruised areas and drying produce with a clean towel or paper towel before eating.

When traveling, choosing cooked options when possible may further lower risk, since proper cooking temperatures can inactivate many foodborne pathogens. Prepared salads, uncooked herb garnishes and pre-cut fruit mixes are harder to assess visually for contamination, so some travelers may decide to limit these items while outbreak investigations continue.

Frequent handwashing with soap and water, particularly before eating and after using the restroom, remains an important layer of protection. Travelers using shared kitchen facilities in vacation rentals or campgrounds should pay close attention to cleaning cutting boards, knives and countertops that come into contact with raw produce.

Anyone who develops prolonged, watery diarrhea, especially lasting more than a few days or accompanied by significant fatigue, weight loss or dizziness, is advised by public health guidance to seek medical care. Clinicians can request specific testing for Cyclospora if they suspect cyclosporiasis, and targeted antibiotic treatment is available once a diagnosis is confirmed.