They belong to the invasive species and are also multiplying more and more in our latitudes: the Asian tiger mosquito and the yellow fever mosquito. The WHO is now warning that dengue fever could also spread rapidly in Europe because of these pests.
The danger is growing due to climate change and the associated rise in temperatures, said WHO specialist Diana Rojas in Geneva on Friday. This year, Italy has reported 82 locally transmitted infections, France 43, and Spain three.
Eggs do not survive local winters
Rojas said European countries still have the chance to prevent these mosquitoes from spreading further. The number of reported cases worldwide increased tenfold between 2000 and 2019. Small populations of the tiger mosquito and the yellow fever mosquito (Aedes albopictus and Aedes aegypti), which transmit dengue fever, already exist in southern Europe.
The eggs could survive the winter, and larvae could hatch when it gets warmer. According to the WHO, most cases this year have been reported from North and South America—more than 80 percent.
Mosquitoes are mostly active during the day
Aedes mosquitoes are mostly active during the day. They are mainly found in tropical and subtropical regions but are spreading rapidly, both to other latitudes and to higher altitudes; in Nepal, for example, to more than 2000 meters. The viral infection is often mild, but in ten percent of cases, it can cause serious complications.
The WHO estimates the number of infections at almost 400 million a year. Only a fraction of these are actually diagnosed and reported. Effective treatments do not yet exist.
Fever and rash
The signs of the disease usually appear three to ten days, rarely up to 14 days after the bite. The so-called dengue triad is typical: fever, rash, headache, muscle, limb, bone, or joint pain. The severe course often only occurs after repeated infection with dengue virus. Dengue fever is noticeable in Austria.
- source: krone.at/picture: Bild von Mohamed Nuzrath auf Pixabay