West Nile viruses are avirus is a highly contagious agent to a wide range of hosts. Its spread in the Mediterranean region raises several questions about its origin and the risk factor underlying the virus dispersal. This study aims to reconstruct the temporal and spatial phylodynamics of West Nile Virusvirus lineage 2 in the Mediterranean region using complete genome sequences from different host species, retrieved from international databases. Phylogeographic analysis suggested that WNV-2 likely originated in South Africa or nearby regions at the beginning of the 20th century to spread northwards since the early 2000s, via at least one route crossing the Mediterranean to reach Hungary, to spread thereafter throughout Europe.
The present work suggests another penetration event in 1978 from Africa to Europe. Migratory birds constitute, among others, additional risk factors that enhance the geographical transmission of the infection. Our data underline the importance of the spatial-temporal tracking of migratory birds and phylodynamic reconstruction in setting up an efficient surveillance system for emerging and reemerging zoonoses in the Mediterranean region.