UK holidaymakers are being warned about a significant increase in cases of cyclosporiasis, an infectious disease that can cause severe diarrhoea. The UK Health Security Agency (UKHSA) has reported 67 cases since April 2026, with many among travellers returning from Mexico.
Between April 30 and July 15, 2026, 30 cases were reported in England, 27 in Scotland, and 10 in Wales. Of the 52 cases where travel information was available, 48 individuals had travelled to Mexico, often staying in all-inclusive resorts in areas like Riviera Maya and Cancún.
The illness is caused by the cyclospora parasite, which can contaminate foods such as salads, herbs, and soft fruits. It does not naturally occur in the UK and is not spread from person to person. The UKHSA anticipates further cases due to increased summer travel to Mexico and potentially the US.
To protect themselves, travellers are advised to follow good food and water hygiene, including drinking bottled water and eating thoroughly cooked food, even in high-end resorts. Experts also recommend avoiding uncooked berries, herbs, unpeeled fruit, and salad items.
Dr Philip Veal from the UKHSA advises anyone developing symptoms like watery diarrhoea, loss of appetite, or stomach cramps after returning from travel to seek medical attention and inform their healthcare professional of their travel history.