The World Health Organization (WHO) warns of the spread of certain mosquitoes in Europe and thus an increase in dengue cases. The danger is growing due to climate change and the associated rising temperatures, said WHO specialist Diana Rojas in Geneva.

This year, Italy reported 82 locally transmitted infections, France 43 and Spain 3. European countries still have the chance to prevent these mosquitoes from spreading further, if possible, said Rojas. Worldwide, the number of reported cases increased tenfold from 2000 to 2019.

Mosquito eggs survive the winter

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 the weather got warmer. According to the WHO, most cases this year were reported in North and South America, more than 80 percent.

Aedes mosquitoes are mostly active during the day. They occur primarily 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 it can cause serious complications. The WHO estimates the number of infections at almost 400 million per year. Only a fraction of these are actually diagnosed and reported. There are currently no effective treatments.

Long sleeves help

People can protect themselves by using mosquito spray and long-sleeved clothing. Breeding areas such as standing water would have to be removed. This also includes, for example, plant saucers on the balcony.

According to the WHO, most cases have been reported from North and South America this year, more than 80 percent. However, monitoring is not sufficient in many places, so many infections are not even reported.