Common mosquito (Culex pipiens). Photo: Josué Martínez de la Puente

A scientific team from the Doñana Biological Station – CSIC, the University of Granada and the Mosquito Control Service from the Huelva Provincial Council has analysed the presence of avian malaria parasites in the common mosquito with molecular techniques. The study, published in the journal iScience, was conducted in localities in the provinces of Seville, Huelva, and Cádiz in southern Spain with different land uses. The aim of the study was to determine if habitat type influenced the presence of avian malaria parasites.

The team analysed over 16,500 mosquitoes, which were grouped into more than 750 pools of common mosquitoes (Culex pipiens). In total, parasites were found in 32,7% of the mosquito pools, including 13 different genetic lineages of avian malaria parasites of the genus Plasmodium. This supports the significant role of this species as a potential vector of a wide range of this genus lineages. Martina Ferraguti, first author of the study and Ramón y Cajal researcher at the Doñana Biological Station, explains, “We find higher Plasmodium richness in natural than rural areas, suggesting that habitat characteristics notably impact the diversity of parasites circulating in mosquitoes in southern Spain”. The team also found that Plasmodium prevalence and richness in mosquitoes were higher in areas farther from marshes and rivers.

The common mosquito, a key vector species of avian malaria

Culex pipiens is a common species in Spain, involved in the transmission of different pathogens. Studying the transmission dynamics of avian malaria parasites can help to understand the environmental factors that influence the epidemiology of vector-borne diseases in nature. 

According to Josué Martínez de la Puente, a researcher at the Doñana Biological Station, “Our studies have shown that the common mosquito plays a significant role in the transmission of avian malaria parasites”. These parasites naturally circulate in nature and infect birds through mosquito bites. While aian malaria affects bird health, reproductive success, and survival, but it does not pose any danger to humans.

The results have been obtained within research projects funded by the Junta de Andalucía (Andalusian government) (P11-RNM-7038), the Organismo Autónomo Parques Nacionales (PN2022-2945), and the Leonardo Grant of the BBVA Foundation. This study is a fundamental step in understanding how environmental characteristics affect the epidemiology of mosquito-borne parasites. 

Reference

Ferraguti M, Martínez-de la Puente J, Ruiz S, Soriguer RC, Figuerola J. 2024. Landscape and mosquito community impact the avian Plasmodium infection in Culex pipiens. iScience. 27(3):109194. doi: https://doi.org/10.1016/j.isci.2024.109194