diarrhoea

The cyclospora parasite causes explosive diarrhoea and contaminated food, particularly herbs, salad and soft fruit, are common sources of infection

There has been a rise in Brits contracting a parasite that causes explosive diarrhoea.

The UK Health Security Agency (UKHSA) data shows a “sharp rise” in cyclospora infections among people who’ve travelled to Mexico. 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, UKHSA said. A total of 67 cases have been reported across the UK between April 30 and July 15.

The agency has now advised all travellers to take precautions when going abroad by maintaining good food and water hygiene to reduce the risk of infection. Besides frequent watery diarrhoea, cyclospora also causes abdominal cramping, bloating, nausea, flatulence, low-grade fever, loss of appetite and weight loss.

Infections are usually mild and most people improve within a few days without treatment. However, these can present as more severe or prolonged in people who are immunocompromised and antibiotics may be prescribed.

Data published today shows that, out of the 67 cases reported in travellers returning to the UK, 30 of those were in England, 27 in Scotland and 10 in Wales. The UKHSA says this is a “sharp rise” compared to the annual average of 93 cases recorded between 2022 and 2025.

Travel information is available for 52 out of the 67 cases, with 48 of those reported to have travelled to Mexico. One of the 48 also reported travelling to the United States of America.

A further case reported travelling to the USA only and one to Kenya. Those who travelled to Mexico 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 around the cases are ongoing. UKHSA said it anticipates a continued rise in travel-associated cases as an increased number of people travel to Mexico during the summer.

Travel to the USA, where a widespread outbreak has been reported, could also potentially increase the number of cases in the UK.

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.”

UKHSA is liaising with ABTA, the travel association, and Mexican public health authorities to inform investigations into the rise in cases.

Certain holiday destinations have seen a rise in cases of a nasty infection

British travellers have been issued a food warning amid an outbreak of a bug that causes “explosive” diarrhoea. Mexico and the US are among some of the holiday destinations that have seen a rise in cyclosporiasis.

Cyclosporiasis is an infection caused by a microscopic parasite called Cyclospora. This is typically spread by eating food or drinking water contaminated with human faeces containing the parasite.

Symptoms can include “watery diarrhoea” and “explosive bowel movements”, and can last several weeks. In an update provided on its website, Travel Health Pro explained that “most” UK cases have been linked to visits to Mexico.

It said: “Cyclospora is a parasite found in some tropical and subtropical countries. In the UK, infections are most commonly linked to summer travel abroad.

“Cyclospora has been found in Central and South America, South and Southeast Asia, and most UK travel-related cases and outbreaks have been associated with visits to Mexico.”

The US Centres for Disease Control and Prevention (CDC) also recently published data showing there had been 843 confirmed cases of cyclosporiasis in the US between May 1 and July 9 this year. No deaths have been reported, and 86 people were admitted to hospital, the CDC said.

As part of its advice, Travel Health Pro provided guidance on eating while abroad. It said: “People usually become infected by eating or drinking food or water contaminated with human faeces. Foods most commonly linked to Cyclospora include fresh produce such as soft or unpeeled fruit, lettuce, green salads and herbs like coriander or basil.”

It continued: “You can reduce your risk of Cyclospora infection by following good food and water hygiene, even if you are staying in a luxury hotel or high-end all-inclusive resort.” To do so it said you should:

• Wash your hands regularly with soap and clean water; use alcohol hand gel only when handwashing is not possible
• Where there is no clean water supply, drink only bottled or boiled tap water (this includes brushing your teeth)
• Avoid ice in drinks
• Avoid fresh produce that may not have been washed with bottled or boiled water, including berries, salads, vegetables and herbs like basil or coriander
• Choose fruit that you can peel yourself, such as bananas and oranges
• Eat food that has been freshly cooked and is served hot
• Remember that smoothies, juices and other drinks may contain raw fruit, herbs or vegetables

Symptoms

Travel Health Pro said: “Not everyone infected with Cyclospora will become ill. If you do get symptoms, they will usually start about a week after consuming contaminated food or drinks.”

Symptoms of Cyclosporiasis include:

• Watery diarrhoea
• Fever
• Stomach cramps
• Loss of appetite and weight loss
• Tiredness and muscle pain
• Bloating and excess wind
• Feeling sick

It said: “Cyclospora infections are usually mild and resolve themselves. However, symptoms can sometimes last for several weeks and return even after a person seems to have recovered. People with a weakened immune system, including those living with HIV, may be at greater risk of severe illness.”

The CDC added: “Cyclospora infects the small intestine (bowel) and usually causes watery diarrhoea with frequent and sometimes explosive bowel movements.”

When to seek help

Travel Health Pro says you should do the following if you become ill abroad:

• Drink plenty of “safe” fluids, such as bottled water, or tap water that has been thoroughly boiled and cooled
• Use oral rehydration solutions so that you do not become dehydrated
• Get early medical advice if you have a weakened immune system or are at higher risk of complications
• Seek medical help if your symptoms are severe or do not improve

If you are back in the UK, you should ask for an urgent GP appointment or get help from NHS 111 if you have diarrhoea and you’ve recently travelled abroad and:

• The diarrhoea is severe and has lasted for more than three days
• You have bloody diarrhoea or bleeding from your bottom
• You have a high temperature (fever)
• You are dehydrated
• You have a weakened immune system or other condition

The NHS said: “If you’re still abroad, get medical advice where you are as soon as possible.”