scientists warn that climate change makes Europe a incubator for diseases transmitted by mosquitoes. Longer summer, higher temperatures and heavy rains create favorable conditions for mosquitoes in regions in which they could not thrive beforehand.

The figures published by the European Center for Prevention and the Control of Diseases (ECDC) show that there have been 715 locally transferred cases of the West Nil virus (WNV) in 15 European countries this year. This exceeded the number of cases compared to the same period of the previous year and the 10-year average. By September 4, 51 people died of the consequences of the infection.

"This is the new normal," says Céline Gossner, specialist for emerging and vector -handed diseases at the ECDC in Stockholm, Sweden. The number of WNV cases is expected to rise until September and October. Districts advise people who live in areas in which outbreaks were reported to take precautions to avoid mosquito stitches.

"We are faced with the problem that new places could become a hotspots of the transmission that were not prepared for this," explains Houriiyah Tegally, genome education sepa -upemiologist at the University of Stellenbosch in South Africa.

fatal fever

About 20 % of WNV infections lead to fever of the West Nil virus, which causes fever, headaches, vomiting and tiredness. In less than 1 % of cases, neurological complications occur that can include a life -threatening swelling of the brain.

"Typically most of us have an immune system that simply combats the virus," says Stephen Rich, medical zoologist at the University of Massachusetts Amherst. However, older people and people with a weakened immune system are more susceptible to more serious complications, he adds. In Europe, most of the reports reported are among over 65-year-olds.

The Culex Pipiens Moskito, the WNV transfers from infected birds to humans and other animals, especially horses, is native to Europe. The virus has been on the continent since the 1950s. However, climate change has led to extended transmission periods, so that more regions are confronted with outbreaks, including areas in which no WNV infections were previously reported. "If these viruses spread in communities that have no previous immunity, you can observe large outbreaks," says Rachel Lowe, climate scientist at the Barcelona Supercomputing Center in Spain. A study published at the beginning of this year comes to the conclusion that climate change has made the spatial spread of the WNV in Europe easier. Data track category = "References"> 1

warm conditions have also led to the Asian Tigermoskito aedes Albopictus , which transfers "tropical" diseases such as Denguefieber and Chikungunya. This species has now established itself in 13 European countries and was introduced in 7 others. As a result, both illnesses spread: this summer, Italy and France reported 22 locally transferred cases from dengue fever, and a case of Chikungunya was demonstrated in France.

Since the number of warm and wet days increases, mosquitoes - which thrive in these conditions - spread "in higher widths and also in higher locations," says Lowe.

Although climate change is an important factor for the outbreaks of diseases, it is not the only reason. Increase in travel, especially after COVID-19 pandemic, promotes the transfer of viruses across borders. The increase in dengue cases in Europe is partly a side effect of the records of records in other parts of the world: South and Central America are currently fighting against the worst dengues season ever, with the cases in 2024 already about 230 % higher than at the same time in the previous year.

A preprint from July, in which Tegally is involved as co-author, showed that Denguevirus tribes in Ethiopia are very similar to the tribes in the outbreak in Italy in 2023. Data track label = "Go to Reference" Data Track Category = "References"> 2 "It is impossible to prove the direction of this movement," says Tegally. But this "shows us that the world is very networked, and Europe could also act as a source of these arboviruses at a certain point in time because there are local transmissions."

avoid stitches

With the increase in diseases transferred by mosquitoes in areas in which they were rare before, researchers advise people to pay attention to it, to avoid stitches by using mosquito deflectors, wearing long -sleeved, light -colored clothes and covering windows with mosquito grilles.

Avoiding the standing water in urban gardens, pots or flower vases also helps to reduce the number of potential breeding grounds, says Lowe. The Asian tiger moskito can be easily recognized by its black and white striped legs, adds.

scientists also warn of the risk of asymptomatic carriers that unknown blood banks with diseases such as WNV when they donate blood. "Although the risk is well contained because we have many tests and procedures, it could affect the availability of blood and organ stores," says Celine. The US Centers for Disease Control and Prevention found that 190 blood donors in the United States were tested positively for WNV this year.

emerging risks such as these illustrate the need for careful monitoring of diseases transmitted by mosquitoes, also in areas where they are not endemic.

"There is always a risk that a new vector -handed disease will occur," says Gossner. "We have to be prepared."