[Genotyping of West Nile fever virus strains circulating in southern Russia as an epidemiological investigation method: principles and results].

Aim: Characteristic of West Nile fever (WNF) virus strains circulating in southern Russia.

Materials And 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.