The UK Health Security Agency (UKHSA) has published new data showing a sharp rise in infections causing 'explosive diarrhoea', with most cases linked to travel to Mexico.
Rise in Cyclospora Cases
UKHSA is advising all travellers to take precautions abroad, including maintaining good food and water hygiene. Cyclospora is a parasite that causes 'explosive diarrhoea', according to the health body. Contaminated food, specifically herbs, salad and soft fruit, are common sources. Infection is acquired via consumption of contaminated food. Cyclospora does not naturally occur in the UK and there is no risk of person-to-person spread.
Symptoms can include frequent watery diarrhoea, abdominal cramping, bloating, nausea, flatulence, low-grade fever, loss of appetite and weight loss. While usually mild and most people improve within days without treatment, infections can be more serious or prolonged in immunocompromised individuals, and antibiotics may be prescribed.
Case Numbers and Travel Links
UKHSA said the latest data, published today, showed 67 cases reported in returning travellers in England (30 cases), Wales (10 cases) and Scotland (27 cases) between April 30 and July 15 2026. This represents a sharp rise compared to the annual average of 93 cases recorded between 2022 and 2025. Travel information was available for 52 of the 67 cases; of these, 48 reported travel to Mexico, with one also reporting travel to the USA. One further case reported travel to the USA only, and one to Kenya.
Among those who travelled to Mexico, cases reported staying at a range of hotels in the Riviera Maya and Cancún regions and consuming a variety of food and drink as part of all-inclusive holiday packages. Further investigations are ongoing, UKHSA said. It anticipates a continued rise in travel-associated cases linked to increased summer travel to Mexico and a potential increase in cases linked to travel to the USA, where a widespread outbreak has been reported.
Official Advice and Response
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.' He added that travellers can reduce risk by following good food and water hygiene measures, including drinking bottled water and eating thoroughly cooked food, even in high-end all-inclusive resorts. They should also avoid fresh uncooked berries and herbs, unpeeled fruit and salad items.
UKHSA is liaising with ABTA and Mexican public health authorities to investigate the rise. It continues to work with the National Travel Health Network and Centre (NaTHNaC) to ensure appropriate advice for UK travellers. Further advice is available on NaTHNaC’s TravelHealthPro website.
