The UK Health Security Agency (UKHSA) has published new data showing a sharp rise in cyclospora infections among travellers returning from Mexico.

UKHSA is advising all travellers to take precautions when travelling abroad including maintaining good food and water hygiene to reduce their risk of infection.

Cyclospora is a parasite that causes explosive diarrhoea. Contaminated food specifically herbs, salad and soft fruit are common sources of outbreaks and infections. Infection is acquired via consumption of contaminated food. Cyclospora doesn’t naturally occur in the UK and there is no risk of spread from person to person.

Symptoms of infection can include frequent watery diarrhoea, abdominal cramping, bloating, nausea, flatulence, low-grade fever, loss of appetite and weight loss. While cyclosporiasis is usually mild and most people improve typically in a few days without any treatment, infections can be more serious or prolonged in people who are immunocompromised and antibiotics may be prescribed.

The latest data, published today, shows that 67 cases have been reported in returning travellers in England (30 cases) Wales and (10 cases) Scotland (27 cases) between 30 April and 15 July 2026; a sharp rise this year when compared to the annual average of 93 cases recorded between 2022 and 2025.

Travel information is available for 52 out 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 different 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 around the cases are ongoing.

UKHSA 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.

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.

If you develop symptoms after returning from travel, such as watery diarrhoea, loss of appetite, weight loss, stomach cramps or pain, bloating, increased wind, nausea, fatigue or other flu-like symptoms, please seek medical attention and inform your healthcare professional of your travel history.

The TravelHealthPro website has more information on the steps you can take to keep yourself and your family well.

UKHSA is liaising with ABTA and Mexican public health authorities to inform investigations into the rise in cases. We continue to work with the National Travel Health Network and Centre (NaTHNaC) to ensure appropriate advice is in place for UK travellers.

Further advice is available on NaTHNaC’s TravelHealthPro website, including specific information on cyclospora and summer travel.