The warmer climate is causing infectious disease-transmitting insects to move to Africa's new latitudes and geographical regions. This is the case of mosquitoes of the genus Anopheles, responsible for malaria transmission, according to a new study conducted by scientists at Georgetown University Medical Center in the United States.

From the pre-industrial period to the present day, the average temperature of the planet has already increased by 1.2° C and the prospect is to get warmer. In the recent analysis, published in the journal Biology Letters on Wednesday (15), researchers indicate that the increase in temperature caused mosquitoes in sub-Saharan Africa to move, annually, 6.5 meters toward higher areas and 4.7 kilometers south of the Equator.

As a region warms up, mosquitoes search for other places with favorable temperatures so they can live and reproduce. Usually, the highest and farthest places from the Equator are colder.

The movement of species has been going on for some time. In 2011, experts estimated that terrestrial specimens were moving at a rate of 1.1 meters per year, and to polar latitudes at 1.7 kilometers per year. However, the speed at which mosquitoes are moving is much higher.

New locations

To reach this conclusion, the team analyzed a data set compiled by several entomologists between 1898 and 2016 to track the limits of reach of the Anopheles mosquito. The research focused primarily on malaria mosquitoes, both because of their ability to spread the disease and the set of unique historical data that tracks their movements.

"If mosquitoes are spreading in these areas for the first time, this may help explain some recent changes in malaria transmission that would otherwise be difficult to track down to the climate," says Colin Carlson, assistant research professor at the Center for Global Health Science and Safety at Georgetown University Medical Center,  in a statement.

The study warns that in recent years, in addition to malaria, other mosquito-borne diseases such as dengue and Zika have also expanded to new latitudes and elevations. The movements tend to continue in the future, since the insects follow the thermal limits of transmission established by the need to adapt the body temperature to the environment.

"We tend to assume that these changes are happening around us, but the evidence base is quite limited," Carlson acknowledges. More research is needed for scientists to get a say on what is happening in different regions or with different diseases to get the most comprehensive picture possible.

"We know so little about how climate change is affecting the biodiversity of invertebrates. Public health is giving us a rare opportunity to observe how some insects may be thriving in a changing climate, even if it's bad news for humans," he says.

Source: Um só Planeta