Pathogen diversity in mosquitoes (Diptera: Culicidae) from the Republic of Kosovo: a two-year cross-sectional study

Background Mosquitoes (Diptera: Culicidae) are important vectors of human and animal pathogens. Balkan countries in the southeastern part of Europe exhibit a diverse mosquito fauna and can act as a crossway for both natural and anthropogenic introduction. Some countries however lack data on mosquito fauna distribution, diversity, and pathogen circulation. Methods mosquitoes were trapped in all seven districts of Kosovo in July and August of both 2022 and 2023, then were investigated for the presence of pathogens using PCR-based methods. A total of 144 different locations were surveyed using up to three CDC miniature light traps. Individual trapped mosquitoes were morphologically identified, then pooled, and DNA/RNA was isolated. Identification was confirmed by cytochrome oxidase I ( COI ) barcoding, and PCR-based pathogen screening was performed, targeting the medically relevant Filarioidea, Plasmodium and trypanosomatid protozoans as well as arboviruses (West Nile, Dengue and Zika virus). Results Altogether 6491 mosquitoes belonging to 18 species in six genera were trapped, identified, and screened in 1,122 pools. Of 986 female pools, 21 pools (2.1%) tested positive for DNA of filarioid helminths ( Dirofilaria immitis and D. repens ), 52 pools (5.3%) tested positive for avian Plasmodium DNA, and 82 (8.3%) tested positive for trypanosomatid DNA. Conclusion This study thus presents the most extensive survey of mosquitoes and their parasites in Kosovo to date, providing data on the prevalence of the animal and human pathogens, Filarioidea, Plasmodium and Trypanosoma .