[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. 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. CONCLUSION: 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.

[Results of examination of healthy residents in the southern region of Russia and patients feverish to pappataci fever virus antibodies].

Sera from patients with acute seasonal fevers and apparently healthy individuals living in the Astrakhan Region, Krasnodar Territory, or Rostov Region were examined in two modifications of enzyme immunoassay for detection of IgM and IgG antibodies to Neapolitan and Sicilian pappataci fever viruses. IgM antibodies to Sicilian pappataci fever virus were detected in a patient from the Volodarsky District, Astrakhan Region, who had been admitted for the unverified diagnosis of Q fever. A donor residing in the Novorossiysk District, Krasnodar Territory, was found to have IgA antibodies to Neapolitan pappataci fever virus. The findings show it expedient to conduct further investigations of the serodiagnosis and seroepidemiology of pappataci fevers in the southern Russian region where mosquitoes of the genus Phlebotomus inhabit.