title: West Nile virus circulation in South-Eastern Romania, 2011 to 2013.
abstract: Lineage 2 West Nile virus (WNV), previously found only in sub-Saharan Africa and Madagascar, was identified in Hungary in 2004 and has rapidly expanded in Europe in the past decade. Following a significant outbreak of West Nile fever with neurological cases caused by lineage 1 WNV in Romania in 1996, scattered cases have been recorded in the south-east of the country in each transmission season. Another outbreak, affecting a larger area and caused by lineage 2 WNV, was recorded in 2010. We analysed human sera from neuroinvasive West Nile fever cases and mosquitoes, sampled in south-eastern Romania between 2011 and 2013, for the presence of WNV genome, and obtained partial NS5 and envelope glycoprotein sequences. Human- and mosquito-derived WNV sequences were highly similar (99%) to Volgograd 2007 lineage 2 WNV and differed from isolates previously detected in central and southern Europe. WNV was detected in one pool of Culex pipiens s.l. males, documenting vertical transmission. Lineage 4 WNV, of unknown pathogenicity to mammals, was found in the amphibian-feeding mosquito Uranotaenia unguiculata from the Danube Delta. Our results present molecular evidence for the maintenance of the same isolates of Volgograd 2007-like lineage 2 WNV in south-eastern Romania between 2011 and 2013.
authors.affiliation: Molecular Epidemiology Laboratory, Cantacuzino National Institute of Research-Development for Microbiology and Immunology, Bucharest, Romania.
authors.forename: S
authors.initials: S
authors.lastname: Dinu
authors.forename: A I
authors.initials: AI
authors.lastname: Cotar
authors.forename: I R
authors.initials: IR
authors.lastname: Pănculescu-Gătej
authors.forename: E
authors.initials: E
authors.lastname: Fălcuţă
authors.forename: F L
authors.initials: FL
authors.lastname: Prioteasa
authors.forename: A
authors.initials: A
authors.lastname: Sîrbu
authors.forename: G
authors.initials: G
authors.lastname: Oprişan
authors.forename: D
authors.initials: D
authors.lastname: Bădescu
authors.forename: P
authors.initials: P
authors.lastname: Reiter
authors.forename: C S
authors.initials: CS
authors.lastname: Ceianu
mesh_terms: D000818:Animals; D009033:Culicidae / Q000821:virology*; D004196:Disease Outbreaks; D016678:Genome; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral; D060888:Real-Time Polymerase Chain Reaction; D012383:Romania / Q000453:epidemiology; D014901:West Nile Fever / Q000097:blood / Q000453:epidemiology* / Q000635:transmission; D014902:West Nile virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D012367:RNA, Viral