UKHSA

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.

Some people who fall ill will suffer more than others

The UK Health Security Agency (UKHSA) has issued an alert to certain holidaymakers, with some told to avoid particular areas while abroad. It comes as cases of a rare disease have jumped up, as per the most recent figures.

UKHSA said in a post on X, formerly Twitter: “Are you, or someone you know, heading off on a tropical trip? It’s worth being aware of chikungunya, a mosquito-borne virus that can cause severe joint pain. Check out our blog post to learn how to stay protected.”

Further information within the blog explains that there were 112 confirmed and probable cases of chikungunya reported among travellers returning to England, Wales and Northern Ireland in 2024 – almost one and a half times the number reported in 2023. UKHSA added: “Travel to India accounted for the majority of these cases, followed by travel to Pakistan and Brazil – all popular destinations for people travelling from the UK”.

According to the World Health Organisation (WHO), between January 2025 and September 2025, chikungunya was responsible for 40 deaths in Europe, as well as some 115 deaths in the Americas. There are currently no targeted treatments available for chikungunya, so preventing mosquito bites is essential.

Recommended precautions include using repellent containing DEET or picaridin to exposed skin, and wearing loose-fitting and light-coloured clothing to cover your arms and legs. Mosquitoes breed in standing water around human habitation.

UKHSA is urging travellers to avoid “areas with natural and artificial water containers” to help reduce their risk of exposure. UKHSA guidance adds: “Unlike some mosquito species that prefer rural areas, Aedes mosquitoes thrive in urban environments and often bite indoors, making hotel room precautions equally important.”

Chikungunya symptoms

First symptoms are usually a high fever and severe joint pain, often worse in the small joints or where there have been previous injuries. Many who contract the virus also experience muscle pain, headaches, sensitivity to light, and skin rashes.

Most people make a full recovery within a fortnight, though the joint pain can persist for months or even years in some cases. Around one in every 1,000 people with the virus experience serious complications.

Young babies, elderly people, and those with underlying health conditions are more at risk of serious complications. UKHSA adds: “Occasional complications affecting the eyes, nervous system, heart, and digestive system have been reported.”

Before any overseas travel it is vital to check Foreign Office information, including any health precautions that need to be taken, here

The warning comes as many Brits to prepare to go on their summer holidays

Holidaymakers have been warned to protect themselves against mosquitoes as health officials published new data on infections imported into the UK. The UK Health Security Agency (UKHSA) said diseases spread by mosquitoes, such as dengue fever and Zika virus, can be harmful for some people.

It urged travellers to use insect repellent, wear long sleeves and trousers and sleep under a treated bed net if necessary. People should also get any jabs they need for travel and check whether they need malaria tablets.

Dengue fever can feel similar to flu and symptoms include high temperature, severe headache, pain behind the eyes, muscle and joint pain and feeling sick. Chikungunya symptoms include fever, joint pain, headache, muscle pain, joint swelling and rash.

Most people with Zika suffer a mild illness, but it is serious in pregnant women and can cause stillbirth, miscarriage, problems with development and unusually small heads. Meanwhile, malaria can prove fatal, with symptoms including fever, vomiting and pain.

The UKHSA said eight Zika virus cases were reported from January to June 2026 – already above the seven cases recorded in 2025. Four of these were from Indonesia. Some 137 cases of imported dengue were reported in England from January to June this year, with South-East Asia and South Asia remaining the most common regions where people caught it. Some 27 cases were linked to travel to Thailand and 19 to the Maldives.

For comparison, the overall number of cases by the end of June last year was 161, though cases also tend to rise later in the year. A total of 59 chikungunya cases were reported from January to June this year, with Sri Lanka being the most commonly reported country of travel, accounting for 18 cases. There were 73 in the same period last year.

Meanwhile, 557 malaria cases were reported in England, Wales and Northern Ireland from January to May. Last year at the same point, there were 548. As well as mosquito-borne illnesses, there were 287 cases of typhoid and paratyphoid fever between January and June this year.

Typhoid and paratyphoid are caused by Salmonella bacteria, which is usually spread through contaminated food or water. Mosquitoes rely on standing water to lay their eggs. It then needs to be warm enough for the eggs to hatch, which can take just a few days if temperatures are high enough.

Dr Hilary Kirkbride, consultant epidemiologist and head of travel health at UKHSA, said: “Summer is a popular time to travel – don’t let illness spoil your holidays. Good preparation and planning is important for a safe and enjoyable trip.

“Check the TravelHealthPro website for the latest health advice for your destination, including which vaccines you may need and any important medications, such as anti-malarial tablets.

“To protect against mosquito-borne infections, use insect repellent, cover exposed skin and sleep under a treated bed net where needed. For enteric fever and other stomach bugs, make sure you take good food and water hygiene precautions.

“Even if you have visited a country before, you do not have the same level of natural protection against infections as permanent residents, so it is important to take precautions every time you travel.

“And if you are pregnant or trying to conceive, there are special precautions you should take, so please speak to a doctor, nurse or local travel clinic before planning your trip.”

Natalie Hitchins, Which? head of home products and services, said: “If you’re travelling somewhere that has mosquitoes, it’s worth checking that your repellent will actually do the job before you go.

“Which? tests found that while some repellents provided effective protection for almost 10 hours, some trendy alternatives failed to prevent bites for longer than a few minutes.

“Look for products containing active ingredients such as Deet, Icaridin (picaridin) or PMD, rather than relying on marketing claims alone.

“Insect repellent can help protect against mosquito bites, but it should be used alongside – never as a replacement for – any vaccinations or medications recommended by a healthcare professional.”