Tiger mosquitoes cause huge rise in dengue fever in Europe

Dengue fever is arriving in Europe due to the spread of the tiger mosquito, the European Centre for Disease Prevention and Control (ECDC) has said, with climate change driving the invasive insect’s migration.

Tiger mosquitoes, a more aggressive species that will bite during the day, originate from Southeast Asia. Previously only found in the tropics, its worrying adaptability has allowed it to spread to new habitats, helped by warming global temperatures. The species has now been found in 13 different European countries, from Greece, Spain, and Italy in Europe’s far south, to France and even Germany. The arrivals have brought with them a significant rise in the incidence of dengue fever cases.

From 2010 to 2021, there were a reported 73 locally acquired cases of dengue in Europe. But the numbers have been soaring. 2022 matched the figures for the previous decade, and that number doubled to 130 in 2023.

Hundreds of Europeans are infected with dengue due to international travel every year, but in a sign that the increase might not only be occurring in Europe, over 4900 Europeans caught dengue while travelling abroad in 2023. That’s a record and over three times the number who caught the disease the previous year.

What’s the disease like?

Most people do not develop symptoms. But those who do, experience them within about 4 to 10 days of a bite from an insect carrying the viral infection. They will be flu-like, such as fever, headaches, joint and muscle pain. These debilitating effects will disappear for around 95% of people after around a week, the World Health Organisation (WHO) says. However, a small percentage of those infected go on to develop more serious symptoms, such as intense headaches, painful nausea and vomiting, and joint pain so severe that the disease has earned the moniker “break bone fever”.

There is no treatment other than plenty of fluids and paracetamol for pain. Note that the WHO urges people not to take anti-inflammatories, due to the increased risk of bleeding complications.

Tips to avoid infection

If you are out and about in Europe, or anywhere where dengue is a risk, steps you can take to reduce the chances of being infected mostly involve mozzie awareness:

• Use a repellent containing at least 30% “deet” or diethyltoluamide, IR3535 or Icaridin. Apply it after sunscreen. 
• Wear light-coloured, full sleeve and full trousered clothes. Tightly woven, thicker fabrics, and some new technical fabrics, are best to create a proboscis-proof barrier.
• Be vigilant about open windows and doors with no screens and invest in a plug-in insect repellent for indoors.
• Sleep under a (treated) mosquito net if possible.
• Avoid lingering in places where there is stagnant water where mosquitoes breed.
• Check your environment for standing water in drainpipes, water storage units, water features, and water that might sit in pools under decking, or even in small containers in rubbish bins.