Ecology of West Nile Virus in the Danube Delta, Romania: Phylogeography, Xenosurveillance and Mosquito Host-Feeding Patterns

Research on the Danube Delta Biosphere Reserve, Romania, reveals that West Nile virus (WNV) has experienced at least two separate lineage 2 introductions—one from Africa into the delta and another from Greece into southeastern Romania—during the 1990s and early 2000s. The study, spanning 2014 to 2016, analyzed genetic diversity, phylogeography, xenosurveillance, and mosquito host-feeding patterns using data from over 659,000 mosquitoes. Findings indicate that WNV activity in the region is continuous but low, with evidence of in situ evolution shaping its genetic diversity. Notably, Culex pipiens s.l./torrentium emerged as a potential bridge vector due to its catholic host-feeding pattern, predominantly feeding on non-human mammals and birds. While no WNV-RNA was detected in blood-fed mosquitoes, specific antibodies were found in dogs and horses, suggesting persistent but low virus activity during the study period.

Tomazatos, A., Jansen, S., Pfister, S., Török, E., Maranda, I., Horváth, C., Keresztes, L., Spînu, M., Tannich, E., Jöst, H., Schmidt-Chanasit, J., Cadar, D., & Lühken, R. (2019). Ecology of West Nile Virus in the Danube Delta, Romania: Phylogeography, Xenosurveillance and Mosquito Host-Feeding Patterns. Viruses, 11(12), 1159. https://doi.org/10.3390/v11121159