The UK Health Security Agency (UKHSA) has identified a sharp increase in cases of *Cyclospora cayetanensis*—a parasitic infection—among travelers returning from Mexico.
Public health officials confirmed dozens of laboratory-confirmed cases since the start of summer. While the illness is rarely fatal, it causes severe gastrointestinal distress, including prolonged watery diarrhea, cramping, and bloating.
Most patients reported staying at all-inclusive resorts in the Riviera Maya and Cancun regions. The infection spreads through contaminated food or water, often when fresh produce is washed in local water supplies.
“We are investigating a cluster of cases linked to travelers returning from Mexico,” a UKHSA spokesperson said. “Those who have recently returned from the region and are experiencing persistent symptoms should seek medical advice promptly.”
The parasite is notoriously difficult to detect through standard stool testing. Patients are often misdiagnosed with common food poisoning or viral gastroenteritis. UKHSA has issued guidance to general practitioners across the country, urging them to specifically request tests for *Cyclospora* if a patient reports persistent diarrhea after returning from Mexico.
This isn’t the first time the region has faced such outbreaks. Seasonal spikes have been recorded periodically over the last decade, often coinciding with peak tourism months. The parasites are resistant to many common disinfectants, making them a persistent challenge for food safety protocols in tropical climates.
Symptoms typically manifest within a week of exposure. Without targeted antibiotic treatment—specifically a combination of trimethoprim and sulfamethoxazole—the infection can linger for weeks, or even months, leading to significant weight loss and dehydration.
Health officials are advising travelers to prioritize bottled water and avoid raw, unpeeled fruits or vegetables while visiting the region. For those already symptomatic, the window for effective medical intervention is closing as the number of cases continues to climb.
