Urgent health alert to UK travellers after 'unexpected' surge in life-threatening virus

New figures show soaring levels of illnesses including dengue and malaria caused by exposure to mosquitos
-Credit: (Image: Getty)


The Foreign Office has issued a health alert following a ‘growing public health concern’ as ‘the world has faced an unexpected rise’ in cases and deaths from a life-threatening virus. The World Health Organisation is advising that approximately four billion people in 130 countries are at risk of dengue – a virus spread by mosquitoes found in tropical and subtropical regions worldwide, including parts of Europe.

Travel Health Pro, a subdivision of the Foreign Office, has warned that dengue has ‘spread into regions previously thought to be dengue free’. As of April 2024, over five million dengue cases and over 2,000 dengue-related deaths have been reported worldwide since the beginning of 2024.

An increase in dengue cases has been flagged around the world, including in Asia, Central and South America and across the Caribbean. Dengue is not endemic in Europe, says Travel Health Pro.

READ MORE: Foreign Office issues health alert after serious illness found in UK travellers

But if environmental conditions are favourable in parts of Europe where mosquitoes which can carry dengue live, then travel-related cases may cause the spread of dengue locally. Several European countries have previously reported locally acquired cases of dengue.

In 2023, locally acquired cases were reported in France, Italy and Spain, says the Foreign Office subsidiary.

What is dengue?

Dengue is caused by a virus and is spread by the bite of an infected mosquito which mainly feed during daytime hours, says the alert published at the start of May on Travel Health Pro’s website. There are four different types of dengue virus: DENV- 1, DENV- 2, DENV- 3 and DENV- 4.

What are the symptoms?

The majority of people infected with dengue will not have symptoms, says Travel Health Pro.

“If illness develops, it usually begins suddenly with a high fever, severe headache, muscle and joint pain, nausea, vomiting and a rash. Most infections are self-limiting, with a rapid recovery three to four days after the rash appears,” reads the alert.

Are there treatments for dengue?

A small number of infected people can go on to develop a severe form of the illness – called severe dengue, although previously sometimes referred to as dengue haemorrhagic fever. The symptoms of the severe illness include dangerously low blood pressure (shock), fluid build-up in the lungs and severe bleeding (haemorrhage). All four types of dengue virus infection can lead to either dengue or severe dengue, according to Travel Health Pro.

There is currently no specific drug treatment for severe dengue illness, but there are ‘supportive’ treatments for shock and bleeding, which improves survival. Without this help, severe dengue illness can kill.

Advice for travellers

Before you set off:

  • Travel Health Pro says all travellers, including cruise passengers, who are visiting areas where dengue cases have been reported or where dengue is believed to be present, are at risk of infection

  • Refer to the 'other risks' section on Travel Health Pro's country information web pages to assess the dengue risk at your destination and for specific advice about other health risks

  • Check the Foreign, Commonwealth and Development Office (FCDO) country advice for safety and security information for your destination

  • Consult your GP, practice nurse, pharmacist or travel clinic to ensure all your recommended travel vaccines and UK routine vaccines, including MMR, are up-to-date

  • There is a live, attenuated (weakened) dengue vaccine called Qdenga licensed in the United Kingdom, but it is not suitable for all travellers

While you're abroad:

  • Minimise your risk of all insect-borne illnesses, including dengue, by wearing long-sleeved tops and long trousers and regularly applying insect repellent, according to Travel Health Pro

  • Adhere to insect and tick bite avoidance advice at all times

  • As dengue is transmitted by day-biting mosquitoes, take extra precautions during the day, especially around dawn and dusk

  • Remember that dengue poses a risk throughout the year in tropical countries

  • Insect repellent should be applied after sunscreen and reapplied regularly following any activities, including swimming

  • Insect repellents containing 50% DEET (N, N-diethyl-m-toluamide) are currently the most effective and can be used by pregnant or breastfeeding women, as well as children from two-months-old

  • If DEET is not suitable, alternative insect repellents containing Icaridin (Picaridin); Eucalyptus citriodora oil, hydrated, cyclized; or 3-ethlyaminopropionate can be used instead

  • When staying with friends or family, it's important to reduce mosquito breeding sites around the home by eliminating any stagnant water in plant pots, gutters, drains and rubbish

  • Insecticide treated bed and cot nets offer good protection against mosquito bites when sleeping during the day

Upon your return:

Travel Health Pro says that if you experience symptoms such as high fever, severe headache or a rash within two weeks of returning from a country with a risk of dengue, seek urgent medical help. Remember to inform your GP or nurse about every country you visited.