What is dengue fever? Cases rise across Europe due to spread of tiger mosquitoes
A species of mosquito found in 13 European countries, including France, Spain and Greece, has been linked to a rise in dengue fever on the continent.
The Asian tiger mosquito, aedes albopictus is said to be the most invasive species of mosquito in the world and is now spreading across Europe.
Warmer temperatures due to climate change are creating favourable conditions for the tiger mosquito to spread, according to the European Centre for Disease Prevention and Control (ECDC). The ECDC has also warned that international travel will further increase the risk of more European outbreaks.
People are advised to remove stagnant water from gardens or balconies, where mosquitoes can breed, use mosquito repellent and install flyscreens on windows and doors.
Authorities have been monitoring and trapping the insect in multiple locations including Paris, where the Olympic Games will take place at the end of July. French health authorities announced they were being proactive by deploying “dengue detectives”, after a warning of the risks of imported cases ahead of the Paris Olympics.
The species is a growing threat for Europeans, having become established in Austria, Bulgaria, Croatia, France, Germany, Greece, Hungary, Italy, Malta, Portugal, Romania, Slovenia and Spain, according to the ECDC. It has also been spotted in Belgium, Cyprus, Czechia, the Netherlands and Slovakia.
ECDC director Andrea Ammon said: “Europe is already seeing how climate change is creating more favourable conditions for invasive mosquitos to spread into previously unaffected areas and infect more people with diseases such as dengue. Increased international travel from dengue-endemic countries will also increase the risk of imported cases, and inevitably also the risk of local outbreaks."
Tiger mosquitoes can spread diseases such as dengue fever, chikungunya and Zika virus.
What is dengue fever?
Dengue fever is an infection spread by mosquitoes. Dengue cannot be transmitted between people.
It usually gets better on its own and it’s rare for people to get a severe type of dengue.
There is no vaccine to prevent dengue and the NHS suggests that the best way to prevent being infected with dengue is to avoid being bitten by mosquitoes.
There is also no specific treatment for dengue, but people should generally rest, drink fluids, and take paracetamol.
What are the symptoms of dengue fever?
Symptoms of dengue fever are similar to the flu and typically appear between four and 10 days after being bitten.
According to the NHS, the symptoms include the following:
a high temperature
a severe headache
pain behind your eyes
muscle and joint pain
feeling or being sick
swollen glands
a blotchy rash made up of flat or slightly raised spots
Where is dengue fever found?
Dengue fever is typically found in tropical parts of the world, such as parts of Africa and Asia, Central and South America, the Caribbean, the Pacific islands, and some southern areas of North America.
However, there is also a risk of being infected with dengue in parts of southern Europe. It has been found in Croatia, France, Italy, Spain, and Portugal. Dengue is not found in the UK.
Is there a risk of dengue fever in the UK?
Mosquitos carrying dengue fever could become established in England by the middle of the century because of climate change, government health experts have previously said.
Warmer conditions have allowed the biting insects to spread across much of Europe in recent years, travelling alongside humans and through the transportation of goods.
In a report about the health effects of climate change, the UK Health Security Agency (UKHSA) warned the mosquito could become widely established across the UK eventually.
Most of England will become suitable for the establishment of new domestic mosquitoes by the 2040s and 2050s, according to the report.
For most of the rest of the UK, these mosquitoes may become established by the 2060s or 2070s.
"Slower and reduced warming is likely to delay these risks by decades or beyond this century," according to the report.
UKHSA chief executive Prof Jenny Harries said: “Things that when I trained many years ago were called tropical diseases will actually become national domestic diseases.”
Officials also said other food or water-based infectious diseases could become more common, with an increased risk of pandemics.
The Earth has already warmed by 1.2°C above pre-industrial levels and the amount of carbon in the atmosphere means further warming is already locked in, even if emissions start declining overnight.