A parasitic infection spread by contaminated produce is catching travellers off guard this holiday season. The UK has documented 67 cases of cyclospora infection since April, with most cases linked to travel in Mexico, according to BBC Health reporting.
Cyclospora cayetanensis, a single-celled parasite, triggers severe gastrointestinal symptoms including the explosive diarrhoea that has alarmed health officials. The infection spreads through food or water contaminated with the parasite's oocysts, which become infectious after several days in the environment. Fresh fruits and vegetables including berries, lettuce, and basil have been implicated in past outbreaks across North America.
The infection typically emerges seven to ten days after exposure. Symptoms include watery diarrhoea, stomach cramps, nausea, and fatigue that can persist for weeks without treatment. The condition, also called "traveller's diarrhoea," affects the small intestine and causes nutrient malabsorption.
Treatment with trimethoprim-sulfamethoxazole, an antibiotic combination, clears the infection more effectively than other antibiotics. Most cases resolve within two to four weeks, though untreated infections can linger for months.
The uptick in UK cases during the holiday travel season reflects increased movement to endemic regions. Mexico experiences regular cyclospora contamination in its water systems and agricultural areas, particularly in rural districts where sanitation infrastructure remains limited.
Public health authorities recommend thorough handwashing, avoiding tap water in high-risk areas, and cooking produce at high temperatures. Peeling fruits before consumption reduces infection risk, though washing alone does not eliminate all parasites. Travellers returning with persistent diarrhoea should seek medical attention and inform clinicians of their travel history, as cyclospora requires specific diagnostic testing to identify.