The Japanese mosquito that carries the West Nile virus or dengue fever has arrived in Navarre

He Japan mosquito (Aedes Japonicus), a mosquito that transmits pathogenic viruses derived from Japan And Korea which was discovered in Europe (Normandy, France) in 2000, reached Navarre.

The first sighting in Spain occurred in the city Siero (Asturias) in 2018 and in September this year, Enrique Baquero, a researcher at the Biodiversity and Environment Institute (BIOMA) of the University of Navarra, identified a specimen inside a building in Pamplona in broad daylight.

“He promote this mosquito is slowly but continuously moving east of Spain, and so far, in addition to Asturias, it has already been seen in Cantabria and in Gipuzkoa. And its spread, as with other invasive mosquito species, is driven primarily by the movement of people and goods,” he said in a statement.

According to published studies consulted by the expert, the Japanese mosquito has more resistance than other species to winter temperatures found in temperate regions, and the eggs are resistant to freezing and desiccation, remaining inactive during the winter.

In addition, he adds, this species of mosquito has greater resistance to contamination in breeding areas, so they can potentially spread at a faster rate. “In temperate regions such as Navarre, adults will be present from early summer and will remain active until early autumn,” he points out.

For this mosquito species it has been demonstrated vector competition in the transmission of West Nile viruses (WNV), Dengue and Chikungunya. The transmission ability of these arboviruses – viruses that infect vertebrates – he points out raises concerns that this could become a public health problem, especially because they easily colonize urban environments with high population densities.

In this sense, he warns that in Navarre there is a large number birds of prey and the region “is in the bird migration funnel, which increases the potential for WNV transmission as the presence of this new vector is added to the existing species Culex pipiens, which is now “the common vector.” for this virus.”

A recent scientific review (Petersen et al., 2024) assessing the potential risk of mosquitoes to human health found this mosquito among the species in greatest need of observationand is considered to pose a significant risk of transmitting new viruses.

Bakero emphasizes the importance of studying zoonosis – diseases transmitted from animals to humans – and analysis of interactions between human populations and animal communities.