Holidaymakers warned about 'explosive diarrhoea' cyclospora parasite infection

UK holidaymakers are being warned about a nasty infectious illness called cyclosporiasis that can cause explosive diarrhoea after a sharp rise in cases. The UK Health Security Agency (UKHSA) reported that 67 cases have been recorded since April, with many involving travellers returning from Mexico. The warning follows an outbreak in the United States that has infected more than 18,000 people across 45 states. The source of the US outbreak has not yet been identified, and no deaths have been reported. Cyclosporiasis is caused by the parasite Cyclospora, which can contaminate foods such as salads, herbs and washed fruit. The illness does not normally occur in the UK, and experts stress there is no risk of person‑to‑person transmission. Between 30 April and 15 July 2026, the UKHSA recorded 30 cases in England, 27 in Scotland and 10 in Wales. Of the 52 cases for which travel information was available, 48 individuals said they had travelled to Mexico. Many of those respondents indicated they had stayed in the Riviera Maya area or slightly farther north along the coast near Cancún. The UKHSA noted that those affected had stayed in a variety of hotels and consumed a range of foods and drinks within their accommodation as part of all‑inclusive holiday packages. Investigations and monitoring of the situation are ongoing. Travellers can protect themselves abroad by practising good food and water hygiene, including drinking bottled water and eating thoroughly cooked food, even when staying in high‑end all‑inclusive resorts. Experts also advise avoiding raw uncooked berries and herbs, unpeeled fruit and salad items.