RESUMO
AIM: Analysis of hepatitis A (HA) incidence in Tyva Republic in 2008 exploiting traditional epidemiological and molecular methods. MATERIALS AND METHODS: Epidemiological analysis of HA cases and contact persons in Erzinsky and Kyzyl regions of Tyva Republic was performed. Class M and G antibodies to HAV were determined in serum samples (n = 28), and HAV RNA--in stool samples (n = 16). Phylogenetic analysis of HAV RNA sequence was performed for VP1/2A region of the HAV genome with length 394 nucleotides. RESULTS: Cases of HA were registered during 3.5 months. Water supply sources did not have deviations from established standards. According to results of interviews, common food factor, which was able to cause the rise of HA incidence, was not determined. Signs of fecal contamination were revealed on environmental objects in preschool institutions and schools that demonstrate the low level of hygienic behaviour. It was shown that all cases of HA are related with different variants of the virus belonged to genotype IA that points to the absence of common source of infection. CONCLUSION: Results of epidemiological and genetic analysis of HAV demonstrate that observed rise in HA incidence in Tyva Republic are connected with phase of seasonal rise of HA incidence, which is characteristic for its perennial dynamics with active realization of contact route of virus transmission.
Assuntos
Vírus da Hepatite A/genética , Vírus da Hepatite A/imunologia , Hepatite A/epidemiologia , Cisteína Endopeptidases/genética , Fezes/química , Variação Genética , Anticorpos Anti-Hepatite A/sangue , Humanos , Higiene , Incidência , Filogenia , RNA Viral/análise , Federação Russa/epidemiologia , Estações do Ano , Estudos Soroepidemiológicos , Proteínas Virais/genética , Proteínas Estruturais Virais/genéticaRESUMO
The spread and genotypical variability of GBV-C virus were determined among the HIV-positive patients in the Russian Federation. More than a fourth (26.2%) of the HIV-infected patients were shown to have GBV-C coinfection; all virus isolates belonged to genotype 2 with a predominance of subtype 2a. Analysis of the impact of GBV-C coinfection on HIV burden and CD4 lymphocyte levels showed no significant impact on these basic characteristics of HIV infection. However, coinfection with GBV-C and HIV was associated with the higher frequency of undetectably low ( < 400 copies/ml) of HIV burden, which enables GBV-C infection to be regarded as a potentially favorable factor in HIV infection.