Brits warned of mosquito-borne illnesses after rise in cases

The advice comes after health officials published new data on infections imported into the UK.

Officials are urging anyone travelling abroad to:

• Use insect repellent
• Wear long sleeves and trousers
• Sleep under mosquito nets where necessary

Health experts have warned Brits to prepare for mosquitoes before travelling. (Image: Alamy Stock Photo/PA)

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."

More than 100 cases of dengue fever reported in England this year (so far)

Dengue fever is often found in tropical areas, according to the NHS, including:

• Parts of Africa and Asia
• Central and South America
• Caribbean
• Pacific islands
• Southern areas of North America

There's also a risk of getting dengue at certain times of the year in parts of southern Europe, including:

• Croatia
• France
• Italy
• Spain
• Portugal and Madeira

The NHS added: "Dengue is not found in the UK and you cannot catch it from another person."

However, from January to June this year, 137 cases of dengue fever were reported in England.

The highest risk areas were South-East Asia and South Asia, with 27 cases traced back to travel in Thailand and 19 in the Maldives.

Dengue fever symptoms

Dengue fever symptoms are similar to the flu, the NHS said, and include:

• High temperature
• Severe headache
• Pain behind the eyes
• Muscle and joint pain
• Nausea

The health experts added: "If you do have symptoms, they usually start 4 to 10 days after being bitten by an infected mosquito."

Other mosquito-borne illnesses found in the UK

UKHSA data also showed cases of other mosquito-borne illnesses.

Zika virus

There were eight cases of the Zika virus in the first half of 2026—already higher than the seven cases recorded in 2025.

Four of this year’s cases were linked to travel in Indonesia.

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.

Chikungunya

Chikungunya, another mosquito-transmitted disease, led to 59 reported cases, with 18 of those connected to trips to Sri Lanka.

Chikungunya typically causes:

• Fever
• Joint pain
• Rash
• Muscle aches

🦟📰 Our latest data shows that in returning travellers, chikungunya, a mosquito-borne illness that can cause severe joint and muscle pain, rose 43% in 2025 compared to 2024. (1/2)

🔗 Find the full news story here:https://t.co/qupbS4fpBV pic.twitter.com/gbHWxT2sQj

— UK Health Security Agency (@UKHSA) March 26, 2026

Malaria

Malaria also remains a concern.

Between January and May this year, 557 cases were reported across England, Wales, and Northern Ireland—compared with 548 during the same period last year.

The illness can be fatal and causes fever, vomiting, and pain.

Typhoid and paratyphoid fever

UKHSA has also reported 287 cases of typhoid and paratyphoid fever so far this year.

These illnesses are not spread by mosquitoes, but by consuming food or water contaminated with Salmonella bacteria.

Health experts urge Brits to prepare before travelling

Health officials stressed the importance of preparation before travelling.

Dr Kirkbride said: "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."

She warned that natural immunity is not the same for visitors as it is for long-term residents in affected regions.

Dr Kirkbride said: "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."

Have you ever contracted a mosquito-borne illness while away on holiday? Let us know in the poll above or in the comments below.