The UK Health Security Agency (UKHSA) has warned Brits travelling to Mexico about a surge in cyclospora infections, a parasite that can cause severe diarrhoea. Tourists are advised to drink bottled water and eat only thoroughly cooked food to reduce their risk.
Rise in cases
Between 30 April and 15 July 2026, 67 cases of cyclospora were reported among travellers returning from Mexico to England, Scotland and Wales. This is a sharp increase compared with the annual average of 93 cases recorded between 2022 and 2025. Of the 52 cases with available travel information, 48 reported travel to Mexico, one to the USA and one to Kenya.
Symptoms and transmission
Cyclospora causes diarrhoea, abdominal cramps, bloating, nausea, flatulence, low-grade fever, loss of appetite and weight loss. The infection is usually acquired through contaminated food, with herbs, salad and soft fruit being common sources. The UKHSA notes that the infection does not occur naturally in the UK and cannot be spread from person to person.
Advice for travellers
Dr Philip Veal, Consultant in Travel Health at UKHSA, said: "We have recently detected a rise in Cyclospora infections among travellers returning from Mexico. These infections are caused by a parasite and can affect the stomach and intestines. Travellers to Mexico and other areas where the infection is more common can reduce their risk by following good food and water hygiene measures, including drinking bottled water and eating thoroughly cooked food, even when staying in high-end all-inclusive resorts. We also advise avoiding certain foods such as fresh uncooked berries and herbs, unpeeled fruit and salad items."
Cases in Mexico reported staying at various hotels in the Riviera Maya and Cancún regions, and consuming a range of food and drink as part of all-inclusive packages. While most infections are mild and resolve within days, the UKHSA warns that immunocompromised individuals may require antibiotics. Travellers experiencing symptoms such as watery diarrhoea, fatigue or stomach cramps after returning are advised to seek medical attention and inform their healthcare provider of their travel history.
