[Monitoring for influenza in population of Western Siberia in 2007-2009].

AIM: To analyze influenza viruses isolated in the 2008-2009 autumn-winter season, and to test sera collected in the south of Western Siberia during the beginning and the end of the epidemic seasons from 2007 until the A/H1N1 pandemic. MATERIALS AND METHODS: Total 149 clinical samples were analyzed and 2190 blood sera were tested. During the 2008-2009 season 17 influenza viruses were isolated. 9 of these were A/H1N1, 5-were A/H3N2, and 3 were influenza B viruses. The nucleotide sequences and amino acid composition of influenza A virus hemagglutinin (HA) were compared with reference strains. RESULTS: Among A/H1N1 viruses circulating in Novosibirsk region three viruses contained four amino acid replacements in antigen sites Ca, Cb and Sb. In A/ H3N2 viruses from Novosibirsk, 2 amino acid substitutions were detected in antigen sites B and E. CONCLUSION: Based on genotyping influenzae epidemic on February to April of 2009 in the south of western Siberia was associated with influenza viruses A/H1N1, A/H3N2, and B. All A/H3N2 influenza virus isolates were variants of reference A/Brisbane/10/2007(H3N2) and A/ H1N1 influenza viruses isolates were similar to reference A/Brisbane/59/2007(H1N1).

[Occurrence of markers, distribution of genotypes and risk factors for viral hepatitis C among some groups of the population in the Novosibirsk region]. / Vstrechaemost' markerov, raspredelenie genotipov i faktory riska virusnogo gepatita C sredi naseleniia Novosibirskoi oblasti.

The occurrence of markers, genotypic variability of isolates and risk factors for viral hepatitis C (HCV) were studied in 4 groups of residents of the Novosibirsk region (altogether 2,000 persons). Anti-HCV IgG were detected within the range from 4.6% among medical personnel to 48% among the patients of the drug-abuse clinic. The detection rate of HCV RNA in seropositive samples varied from 79.3% to 86.3%. The determination of genotype was carried out for 388 isolates: 1b--50.3%, 2a--4.4%, 2c--0.3%, 3a--44.8%. The highest risk indices with respect to HCV among the residents of the region were linked with the drug use (OR=77.5; p<0.05) as well as with risky behavior and low social status. The elevated numbers of seropositive persons were detected among unemployed (OR=16.3), alcohol abusers (OR=3.9), persons having more than 4 sex partners in their lifetime (OR=4.3) and persons having homosexual contacts (OR=6.6). In some groups blood transfusions also played a definite role in the transmission of HCV. In the analysis, carried out separately for two different genotypes the intravenous use of drugs was perceptibly stronger linked with VHC of genotype 3 (OR=85.5) in comparison with HCV of genotype 1 (OR=49.3) and genotype 2 (OR=41.1). Genotype 1 prevailed in the older age group and genotype 3, among young people.

Molecular epidemiology of the hepatitis C virus in Western Siberia.

Western Siberia is the region with little information on the prevalence of hepatitis C virus (HCV) infection, genotypic diversity of HCV isolates and risk factors. A molecular epidemiological survey was conducted to clarify these issues. Four groups of volunteers were included in a cross-sectional study (n = 500 in each group): health care workers; daycare patients from a hospital for drug users, daycare patients from an AIDS prevention and control center; and persons admitted to a local general practice clinic for any reason (outpatients). The anti-HCV IgG prevalence was 4.6% in health care workers, 48.0% in a narcological center, 35.8% in AIDS center, and 5.6% in outpatients. HCV RNA was found in 79.3%-86.3% of seropositives. A total of 388 HCV isolates were genotyped by direct sequencing and phylogenetic analysis of the 5'-UTR and NS5B regions of HCV genome. The genotypes distribution was: 1b--50.3%, 2a--4.4%, 2c--0.3%, 3a--44.8%. One isolate (0.3%) could not be typed unambiguously. This genotypic diversity is intermediate between that of European Russia and China. Genotype 1 prevailed in an older age group (75% among 51-60 years old), and genotype 3 was most prevalent in young people (51.4% in 16-20 years old). A statistically significant (P < 0.05) increase in risk was found in intravenous drug users (odds ratio (OR) = 77.5), unemployed persons (OR = 16.3), persons having >4 sexual partners during lifetime (OR = 4.3), and male homosexuals (OR = 6.6).