title: [Genotyping of West Nile fever virus strains circulating in southern Russia as an epidemiological investigation method: principles and results].
abstract: OBJECTIVE
  Characteristic of West Nile fever (WNF) virus strains circulating in southern Russia.
  
  
  METHODS
  WNF RNA was amplified directly from clinical samples, mosquitoes and bird tissues by PCR, nucleotides were sequenced directly and analyzed comparatively.
  
  
  RESULTS
  Related but different genovariants of WNF lineage 1a--"Volgograd" and "Astrakhan"--circulated during WNF outbreaks of 1999 and 2000-2003 in Volgograd and Astrakhan regions. In 2005 "Volgograd" WNF variant emerged in Astrakhan region and along with "Astrakhan" variant caused a new morbidity increase. In 2004 in sera of 2 WNF patients from Rostov region WNF lineage 2 RNA was detected, this was the first WNF clinical case caused by WNF lineage 2 outside of Africa. WNF outbreak in Volgograd region in 2007 was caused by this unique WNF lineage that may preliminary be called Russian. Finally, during a major WNF outbreak in 2010 in Volgograd and Rostov regions in clinical samples only russian genovariant WNF lineage 2 RNA was detected again.
  
  
  CONCLUSIONS
  After emergence of a certain WNF genovariant the virus is capable of persisting in natural foci in southern Russia. A near disappearance of one of the WNF clones by substitution or displacement with another maybe possible. Determination of genetic characteristics of WNF strains circulating in Russia is an important element of WNF epidemiological surveillance and control of this disease.
authors: A E
authors: AE
authors: Platonov
authors: L S
authors: LS
authors: Karan'
authors: T A
authors: TA
authors: Shopenskaia
authors: M V
authors: MV
authors: Fedorova
authors: N M
authors: NM
authors: Koliasnikova
authors: N M
authors: NM
authors: Rusakova
authors: L V
authors: LV
authors: Shishkina
authors: T E
authors: TE
authors: Arshba
authors: V I
authors: VI
authors: Zhuravlev
authors: M V
authors: MV
authors: Govorukhina
authors: A A
authors: AA
authors: Valentseva
authors: G A
authors: GA
authors: Shipulin