Health impact of native and non-native invasive mosquitoes: the case of Aedes aegypti

Mosquitoes are among the most hazardous animals on Earth due to their capacity to spread illnesses. Some mosquitoes have colonized new areas far from their native range. It is expected that non-native species would have greater consequences because, in part, to lack of coevolutionary history with the local population. This might also apply to the impact of disease carrying mosquitoes. Of the approximately 3500 mosquito species, around 22 species transmit diseases. One of them, Aedes aegypti, poses the greatest threat to human health. Native to Africa, A. aegypti is an invasive non-native species in Asia and the Americas, and it is the principal carrier of Dengue and Chikungunya. We analyzed the impact on human health of A. aegypti in both its native and exotic range. For Dengue, the tropical areas of the Americas and Asia are the ones with the highest distribution of infections. For example, in 2022 the majority of dengue cases reported were in Brazil (>2 million), Vietnam, the Philippines, Indonesia and India. During 2022 most of the countries in Africa did not have reported cases of dengue, and the ones that had reported cases, the numbers were much lower than in the Americas and Asia. A similar pattern is found for Chikungunya where much less cases are reported in Africa. Our preliminary results suggest that for A. aegypti, the impact is much higher when it is non-native. It would be important to see if this pattern also holds for the other mosquitoes that carry diseases.