The UK Health Security Agency's Travel Health Pro has issued a food warning for British travellers amid outbreaks of cyclosporiasis, a parasitic infection causing explosive diarrhoea, particularly in Mexico and the United States.
Outbreak Details and Affected Regions
Cyclosporiasis is caused by the microscopic parasite Cyclospora, typically spread through food or water contaminated with human faeces. According to Travel Health Pro, most UK cases have been linked to visits to Mexico. The US Centres for Disease Control and Prevention (CDC) reported 843 confirmed cases between 1 May and 9 July 2026, with 86 hospitalisations and no deaths.
Travel Health Pro stated: 'Cyclospora is a parasite found in some tropical and subtropical countries. In the UK, infections are most commonly linked to summer travel abroad.' The parasite has been detected in Central and South America, South and Southeast Asia, and most UK travel-related cases and outbreaks have been associated with visits to Mexico.
Symptoms and Impact
Symptoms include watery diarrhoea, explosive bowel movements, fever, stomach cramps, loss of appetite, weight loss, tiredness, muscle pain, bloating, and nausea. They typically appear about a week after consuming contaminated food or drinks and can last several weeks. The CDC noted that Cyclospora infects the small intestine, causing frequent and sometimes explosive bowel movements.
While infections are usually mild and self-resolving, symptoms may persist for weeks and can recur. People with weakened immune systems, such as those living with HIV, are at higher risk of severe illness.
Prevention Advice for Travellers
Travel Health Pro emphasised that travellers can reduce risk by following good food and water hygiene, even in luxury hotels or all-inclusive resorts. Key recommendations include: washing hands regularly with soap and clean water; using alcohol hand gel only when handwashing is not possible; drinking only bottled or boiled tap water (including for brushing teeth); avoiding ice in drinks; avoiding fresh produce that may not have been washed with safe water, such as berries, salads, vegetables, and herbs like basil or coriander; choosing fruit that can be peeled, like bananas and oranges; eating freshly cooked food served hot; and being aware that smoothies, juices, and other drinks may contain raw fruit, herbs, or vegetables.
Foods most commonly linked to Cyclospora include fresh produce like soft or unpeeled fruit, lettuce, green salads, and herbs such as coriander or basil.
Guidance for Those Who Fall Ill
Travellers who become ill abroad should drink plenty of safe fluids, such as bottled or boiled and cooled tap water, and use oral rehydration solutions to prevent dehydration. Early medical advice is recommended for those with weakened immune systems or at higher risk of complications. If symptoms are severe or do not improve, medical help should be sought.
Upon returning to the UK, individuals should seek an urgent GP appointment or contact NHS 111 if diarrhoea persists for more than three days, if there is bloody diarrhoea or bleeding from the bottom, if there is a high fever, if dehydration is present, or if they have a weakened immune system or other condition. The NHS advises: 'If you're still abroad, get medical advice where you are as soon as possible.'
