The Complete Sequence of a West Nile Virus Lineage 2 Strain Detected in a Hyalomma marginatum marginatum Tick Collected from a Song Thrush (Turdus philomelos) in Eastern Romania in 2013 Revealed Closest Genetic Relationship to Strain Volgograd 2007

In this study the first complete sequence of the West Nile virus (WNV) lineage 2 strain currently circulating in Romania was determined. The virus was detected in a Hyalomma marginatum marginatum tick collected from a juvenile song thrush (Turdus philomelos) in the Romanian Danube Delta close to the city of Tulcea, end of August 2013. Our finding emphasizes the role of ticks in introduction and maintenance of WNV infections. Sequence analyses revealed close genetic relationship of the Romanian WNV strain to strain Reb_Volgograd_07_H, which was isolated from human brain tissue during an outbreak of West Nile neuroinvasive disease (WNND) in Russia in 2007. In 2010 the Eastern European lineage 2 WNV caused an outbreak of human WNND in Romania. Partial sequences from subsequent years demonstrated that this WNV strain became endemic in Eastern Europe and has been causing outbreaks of varying sizes in southern Russia since 2007 and in Romania since 2010.