Outlook: The prevalence of malaria is shifting

A type of gelatin was not found until the end of April (“Anopheles saccharophy”) theoretically capable of combating infectious diseases malaria Transfer to. No cases of the disease have been reported since then, but the Italian government is closely monitoring the situation.

According to experts, it is not necessarily surprising that malaria-carrying gels are now being seen in Europe. One of the main reasons for this is the increase in global warming. “The warmer the weather becomes, the more likely the mosquito’s distribution area will shift northward – including to continents such as Europe and North America,” explains the British geographer. Mark Smith From the University of Leeds to science.ORF.at.

First sighting in 50 years

It is currently difficult to estimate the realistic level of concern when seeing Gilsen species in Italy. After all, malaria was already present in large parts of Europe by the mid-twentieth century – but the disease was successfully eradicated over time through improved infrastructure, health care, and land management.

According to Smith, seeing a malaria-carrying gelatinous substance for the first time in Italy about 50 years ago does not necessarily mean that the disease will soon spread widely there. “In any case, we have to monitor the situation in Europe in the future.”

Area changes are possible

However, the African continent is much less prepared to combat malaria. Two years ago World Health Organization (fromA total of 249 million malaria cases have been recorded worldwide – 94 percent of them in Africa. People in Western and Southern Africa are currently being particularly affected.

“Mosquitoes are found in places where it is warm enough for them and where they find enough standing water surfaces (note: for example, ponds or river banks) in which they can breed,” says Smith. As the weather becomes warmer, the availability of water in an area also changes – so rising global temperatures could have a significant impact on malaria transmission areas in Africa in the future and shift the risk of malaria to other areas.

Extensive model calculations

To verify this assumption, Smith and a British research team created several models that combined numerous projections of temperature increases in Africa with large-scale data on water availability. Researchers are currently providing more detailed information about the accounts in “Science” magazine.

In most previous model calculations of this type, only the expected amount of precipitation relative to water was taken into account. However, this alone is not a good indicator of the actual availability of standing water. “Precipitation usually does not stay in place. So it is not necessarily necessary to draw conclusions about the amount of standing water from this alone,” says the geographer. So the British researchers used additional hydrological features such as evaporation and runoff in their models.

Danger zones are shrinking dramatically

The hypothetical model calculates that the total area of ​​African transport zones could shrink by more than 1 million square kilometers by 2100 because the water will become very hot in many areas and many areas of water will dry up by then. . The decline significantly exceeds previous expectations.

“This is a very large area, but in our models we also assume a scenario in which there will continue to be strong greenhouse gas emissions in the coming years,” Smith explains. “But even if you look more optimistically at the future and reduce emissions, the danger zones in Africa will shrink dramatically.” According to the model's calculations, there may be a particularly strong reduction in potential risk areas in West Africa.

Expected negative consequences

But, according to the geographer, it is not appropriate to talk about good news. Because if it becomes too warm and dry even in Gelsen, this in turn leads to a number of other problems, such as difficulties in agriculture or even greater water shortages in African regions.

At the same time, according to the models, the areas in Africa where malaria pathogens can be transmitted for at least nine months per year are also increasing. “This is especially the case in areas around large rivers,” Smith said. Since a particularly large number of people live in these areas, and the population in African cities will continue to grow, according to the modeling, many more people could live in malaria areas year-round in the future than before. “Our calculations show that up to four times as many people will be living in these areas by 2100.”

basis for further investigations

However, Smith also recognizes that some factors were not taken into account in the new models. “We focused only on climate and water availability. In order to accurately identify future risk areas, more data is needed on other environmental variables that could have an impact on the spread of the disease,” the geographer said.

The biologist also criticizes this Mario Ryker From the University of Exeter in an independent classification. “Finally, while climate plays an important role in the malaria transmission cycle, future intervention measures and developments are likely to have a much greater impact on this disease than climate change,” he assured the agencies.

Smith also believes that the new findings of the British research team are a basis for combining them with more regional studies in the future and thus obtaining more accurate information about the evolution of African malaria regions. According to him, it is important to monitor vulnerable areas in Africa as well as vulnerable areas on other continents and, if necessary, respond quickly to the spread of the disease.