The UK Health Security Agency (UKHSA) has urged holidaymakers bound for Mexico to exercise additional caution after a dramatic surge in cases of tourists contracting cyclospora, a parasite that triggers violent diarrhoea.
Rise in cases among UK travellers
Instances of cyclospora have been documented among individuals who stayed at hotels in sought-after holiday spots within the Riviera Maya and Cancun areas, the UKHSA announced. There have been 67 cases in people returning to the UK between April and July, compared with an annual average of 93 cases recorded between 2022 and 2025. Travel information was available for 52 of the 67 cases, with 48 visiting Mexico and one also travelling to the US. One case visited the US only and one travelled to Kenya.
Symptoms and sources
Typical sources of cyclospora outbreaks include tainted food such as salad, soft fruit and herbs. The infection triggers diarrhoea, cramping, bloating, nausea, loss of appetite and a fever. The parasite causes watery diarrhoea. The majority of cases are minor and resolve within several days without intervention, though certain infections can prove severe or extended and necessitate antibiotics.
Official advice
Dr Philip Veal, consultant in travel health at the 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. Symptoms can include 'watery diarrhoea' and 'explosive bowel movements'."
"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."
According to the NHS, cyclospora is not found in the UK, but there is a risk of contracting it while travelling to places where it's prevalent, such as Central and South America, south and south-east Asia, the Middle East and Africa. There is a significant outbreak of the infection in the US, which has spread to 45 states. Over 18,000 individuals may have been infected, according to the Centres for Disease Control and Prevention, with Michigan being the most affected.
Dr Veal further advised: "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."
The UKHSA is working closely with the Abta travel agents' association and Mexican public health authorities as part of its investigation.
