Global warming encourages transmitting mosquitoes to develop their lives in cooler climate latitudes where they previously did not thrive.

Dengue transmitting mosquito.

The climate crisis and globalization are two essential factors that explain the spread of tropical diseases such as dengue or malaria, which are transmitted by arthropods that act as vectors, in colder latitudes, where before they did not prosper, as explained by a group of experts to the EFE agency.

“The mosquitoes and ticks they are the most common vectors ”, affirms the researcher of Biogeography and Global Change of the National Museum of Natural Sciences (MNCN), Fernando Valladares, who adds that since they lack a heat regulation system they are dependent on outside temperatures.

Thus, the increase in degrees caused by global warming favors them finding “the possibility of developing their life cycle in latitudes with a cooler climate” in which they are found. countries like Spain or Japan and where, in addition, the seasonal pause of proliferation that winter produces on these species has been softened, which makes them “be active for longer.”

The same applies to altitude in the case of malaria, transmitted by female Anopheles mosquitoes. “In the last 30 years, the free level of this disease has risen between 400 and 500 meters” in regions of Africa, Asia and America, so “there are populations that have been left unprotected,” says Valladares.

The globalization is another essential factor since “trips to longer distances in less time” make a person host a pathogen and that the bite of a local insect spreads the disease or that the eggs of these animals are transferred, says the head scientist of the Department of Biodiversity and Evolutionary Biology of the MNCN, Óscar Soriano.

This would be the case of the tiger mosquito, which transmit dengue and that in Spain it is classified “as an invasive species”, says Beatriz Fernández, a researcher in the Public Health Surveillance area of ​​the Carlos III Health Institute (ISCIII), who recalls that “from its Asian origin it has expanded in the last century over wide territories and continues to spread. “

Nile fever

More recent are the multiple cases of West Nile fever recorded this summer in Andalusia and that it is “a disease considered emerging in the world and in Europe,” says Diana Gómez-Barroso, head scientist of the Communicable Diseases area of ​​the National Epidemiology Center (CNE).

“In Spain the first cases in humans were identified in 2010 and some studies had found that there are risk areas in the peninsula, especially in the southwest and southeast and, therefore, that the disease can spread ”since, in addition, the vector is the common mosquito, the most abundant in our country, continues Gómez-Barroso.

However, he clarifies that in 2020 many other factors have concurred due “to the situation generated by the pandemic, such as, for example, the lower human presence and the increased proliferation of vectors and reservoirs“, In addition to” high temperatures and abrupt and abundant rainfall “typical of the climate crisis” that may have contributed to the appearance of the outbreak. “

For his part, the researcher at the Cabanilles Institute of Valencia, Rubén Bueno, warns that human beings “increasingly invade more ecosystems”, modifies habitats and natural cycles and is introduced into environments where it “becomes just another animal” that is exposed to “a disease taking a leap and being human as well.”

“Health encompasses the ecosystems in which we live,” says Bueno, who emphasizes that There is a relationship between the health of nature and that of the human being since, if the first is protected and preserved, people will also be healthy and strong.

All the experts interviewed agree that in the face of vector diseases in areas where there were no cases It is necessary to continue implementing surveillance and control plans and to have a multidisciplinary approach, where entomology, epidemiology and veterinary medicine are involved.

However, they emphasize that reinforcing the planet’s biodiversity and take care of the environment they are the “most effective and sustainable over time” protective barriers for humans.