What is Dengue?
Dengue is a viral infection that is transmitted to humans from infected mosquitoes. Although it is mostly seen in tropical and subtropical climates, it is currently spreading across the world including Europe. However, dengue is still most widespread in Southeast Asia, the western Pacific islands, Latin America, and Africa with Brazil reporting most cases in 2024.
It has 4 types that are dengue virus 1, 2, 3, and 4. Symptoms include fever, aches and pains, nausea, vomiting, headache, fatigue, swollen glands, rash, and muscle, joint, or bone pain. Notably, most people do not experience any symptoms or signs or may interpret dengue as another illness such as flu. Dengue fever may also result in joint pain that can be so painful that one may feel like he has broken his bones. That’s why it is also called breakbone fever. The symptoms typically start within 2 weeks after the bite of an infected mosquito and generally disappear within a week even though symptoms may worsen and can be life-threatening, suggesting the person develops severe dengue fever.
While mild dengue fever leads to fever and flu-like symptoms, severe dengue may cause shock, in other words, a sudden decline in blood pressure, internal bleeding, and even death.
Severe dengue fever, on the other hand, is a medical emergency that happens when blood vessels get damaged and leaky which requires hospital care since it might lead to serious conditions such as shock, organ failure, and death. About 1 in 20 people diagnosed with dengue develop severe dengue, thus despite the percentage of getting severe dengue not being too high, the risk should not be overlooked.
There is no specific medicine for dengue, nonetheless, there is a vaccine called Dengvaxia for people between ages 9 and 45, living in the continental US who had dengue fever at least once before. FDA approved Dengvaxia’s use for children between 9 and 16 living in the U.S. territories of American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands with a dengue history.
Dengue in Europe and Around the World
With the invasion of tiger mosquitoes, 13 countries in the EU including France, Spain, and Greece have been experiencing an increase in dengue fever cases. To exemplify, in 2023, 130 dengue cases in the EU were reported, whereas in 2022 the number was 71, and between 2010 and 2021 there were only 73 cases in total. European countries are not the only ones that encounter a rapid increase in dengue cases. For example, in 2022, there were 2.8 million cases of dengue recorded in the American continent, a fast increase compared to the 1.2 million cases in 2021. Furthermore, in 2016 there were 5.2 million cases, whereas in 2024 until now, there have already been 7.6 million cases worldwide. With approximately 400 million people getting infected with dengue, 100 million getting ill, and 21,000 losing their lives annually, dengue has already become a global and concerning phenomenon. Dengue fever is being detected in more than 100 countries across the world, and the trend seems not pleasant with dengue spreading to more countries including Europe.
According to the European Centre for Disease Prevention and Control (ECDC), climate change acts as a favorable factor for the spread of tiger mosquitoes and for the infection of more people with diseases including dengue.
ECDC forewarns the risk of international travel increasing dengue cases further, therefore authorities are working hard to control the mosquito population and prevent it from escalating, especially in preparation for the Olympic Games that will take place in Paris in July 2024. Since more than 10 million people’s participation is anticipated for the Olympics, the Paris Olympics may possibly become a super spreader event for dengue fever. As ECDC states "increased international travel from dengue-endemic countries will also increase the risk of imported cases, and inevitably also the risk of local outbreaks." For instance, over 4900 people from Europe are infected with dengue during their travels in 2023, the highest number reached so far considering there were 1572 cases observed in 2022. Therefore, it is significant to be extra cautious and aware of the risk especially when traveling to tropical areas where these kinds of viruses are prevalent.
Although Asian tiger mosquitoes also known as Aedes albopictus, which carry not only dengue but also chikungunya and Zika virus, used to be present in only tropical areas of Africa, Asia, and America, they have been established in 13 European countries lately: Austria, Bulgaria, Croatia, France, Germany, Greece, Hungary, Italy, Malta, Portugal, Romania, Slovenia and Spain in addition to being spotted in UK although have not been established yet. Plus, they have been recorded in Belgium, Cyprus, Czechia, the Netherlands, and Slovakia.
Additionally, another mosquito type named Aedes aegypti which transmits yellow fever along with dengue, chikungunya, Zika fever, and many more diseases, has been settled in Cyprus, potentially spreading to Europe in the near future which ECDC considers “concerning”. Likewise, the West Nile virus appears in Europe particularly in Spain more than ever before lately. As ECDC conveys, “One person was reported to be infected by the virus in southern Spain at the start of March, highlighting how climate conditions are creating a suitable environment for mosquitoes”.
Importantly, ECDC recommends clearing stagnant water from gardens or balconies, to avert mosquitoes from reproducing and utilizing fly repellents as well as nets on windows and doors. ECDC director Andrea Ammon also states the importance of taking personal protective measures along with "early detection of cases, timely surveillance, further research, and awareness-raising activities” for minimizing the outbreak.
To sum up, dengue fever cases are unfortunately on the rise worldwide, primarily due to climate change, and the best thing to do for now is to protect yourself from those malicious mosquitoes.
References:
Booth, Mark. “How the Paris Olympics Could Become a Super-Spreader Event for Dengue.” Yahoo News, Yahoo News, 12 June 2024, uk.news.yahoo.com/paris-olympics-could-become-super-111212404.html. Accessed 12 June 2024.
CDC. “About Dengue.” Dengue, 2024, www.cdc.gov/dengue/about/index.html. Accessed 12 June 2024.
“Dengue Fever - Symptoms and Causes.” Mayo Clinic, 2022, www.mayoclinic.org/diseases-conditions/dengue-fever/symptoms-causes/syc-20353078. Accessed 12 June 2024.
“Dengue Worldwide Overview.”
European Centre for Disease Prevention and Control
4 June 2024, www.ecdc.europa.eu/en/dengue-monthly#:~:text=31 May 2024-,Since the beginning of 2024%2C over 7.5 million dengue cases,with Brazil reporting most cases. Accessed 12 June 2024.
Franks, Josephine. “Dengue Fever Cases Rising as Climate Change Draws Tiger Mosquitoes to Europe.” Sky News, Sky, 12 June 2024, news.sky.com/story/dengue-fever-cases-rising-as-climate-change-draws-tiger-mosquitoes-to-europe-13151795. Accessed 12 June 2024.
Roxby, Philippa. “Spread of Tiger Mosquito behind Rise of Dengue Fever in Europe.” Bbc.com, BBC News, 12 June 2024, www.bbc.com/news/articles/ce5520m6x2go. Accessed 12 June 2024.
“Soaring Numbers of Invasive Tiger Mosquitos in Europe Driving Dengue Surge, Experts Warn.” The Independent, 12 June 2024, www.independent.co.uk/climate-change/news/tiger-mosquitoes-dengue-fever-symptoms-b2561035.html. Accessed 12 June 2024.